[RE-wrenches] Neutral run to critical loads sub-panel

[don energysolarnow.com via RE-wrenches]

If all the 120 VAC loads have their neutrals land in the main meter panel then 
there is no need to run a neutral from there to the sub panel, as long as the 
inverter does have a neutral connection back to the meter panel.
Especially when the inverter goes off grid it needs that neutral connection to 
the loads neutral in the meter panel.

Don Barch
Energy Solar



On Mon, Jul 29, 2024 at 11:53?PM William Miller via RE-wrenches
 wrote:
>
> Friends:
>
> I found a grid-tie battery-backup system with a 120/240 VAC critical loads 
> sub-panel that has no neutral run to it.  All of the 120 VAC loads have their 
> neutrals land in the meter panel.
>
> I have always felt instinctively that the neutrals should land in the breaker 
> panel that feeds the circuit.  I have looked through the NEC to find a 
> passage that spells this out but I can seem to find one.
>
> Is this a code requirement?  Is this recommended practice?
>
> Thanks in advance.
>
> William Miller
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com<http://www.millersolar.com>

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[RE-wrenches] Snow mitigation

[don energysolarnow.com via RE-wrenches]

Some time ago there was a post about SMA SunnyBoys that could send current back 
to the solar panels to melt off snow.
This was grid power; but maybe you can use genny or whatever solar power is 
generated to warm up the snowy panels, presuming some of them are uncovered.
Either that or set them steeper to shed the snow.
Don Barch
Energy Solar

Date: Sat, 9 Dec 2023 09:42:33 -0800
From: Bill Battagin 
To: offgridso...@sti.net, Wrenchlist

Subject: [RE-wrenches] Snow mitigation
Message-ID: <2755cb29-257c-427a-ab39-bc6c9c0cc...@psln.com>
Content-Type: text/plain; charset="utf-8"; Format="flowed"

I've been consulting and helping a friend with a mountaintop PV powered
radio system ~7,000' in the No.Sierras. We installed another array this
fall but at 60 degree tilt we're still having problems with snow
accumulation on the PVs, plus once the weather passes it stays too cold
to melt in the bright sun we need to get SOC back up.? Yes, there is
genny back-up, but that's no fun for a solar fanatic.

 ??? ??? ??? Some wrenches have done this kind of install I know, it
would be great to hear of ways to prevent snow from sticking?, ways to
shed it unattended, right? Laser from valley floor!

Thanks,

Bill

Feather River Solar Electric
Bill Battagin, owner
4291 Nelson St. (Shipping)
5575 Genesee Rd. (USPS, UPS)
Taylorsville, CA  95983
530-284-7849, 258-1641(cell)
CA. C10 Lic # 874049
Solar Powered since 1982
Home of the Sunny Side Up



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[RE-wrenches] Sol-Ark phantom loads

[don energysolarnow.com via RE-wrenches]

Just spent yesterday debugging a Sol-Ark 15 kW inverter phantom load weirdness.
With Work Mode set at Limited Power To Home it seemed to get a bit schizo, 
pulling around 6kW in from the grid on leg L1 and around 13 kW on the other L2 
leg, with 7kW of PV added. No house loads were involved. The monitoring called 
this a 13 kW load.
I measured something like 50 amps on L2 and neutral; 120 Volts on L1 and 125 
Volts on L2 at the house. My Fluke clamp-on amp meter does not say which way AC 
current is flowing. The utility meter showed it as  power coming in.
At the main meter panel about 150 ft away from the house the voltages were 
better balanced; probably due to proximity to the utility transformer. Those 
leg voltages were balanced when the inverter was shut down.
Oddly, this phantom loading decreased with decreasing PV production later in 
the day.
Working with Sol-Ark tech support we (of course) downloaded new firmware, then 
changed Work Mode to Limited Power To Load. After a couple of resets this had 
the effect of allowing the inverter to cover just the loads in the 
battery-backed subpanel; not those at the house main panel where the CT sensors 
are located. The phantom 13kW load has not recurred.
Has anyone seen an inverter try to mix import and export on different legs by 
creating phantom loads?

Don Barch
Energy Solar



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Re: [RE-wrenches] Inverter output fluctuations

[don energysolarnow.com via RE-wrenches]

Howie-
 it sounds like the XW+ is trying to curtail the Solar Edge by shifting 
frequency, and the loads don't like it.
When off-grid and batteries are charged there is no place for all that AC 
coupled solar power to go.
This is an issue windmill folks have too. The solution can be as simple as a 
dump load such as a water heater to absorb the excess energy.
Tell the customer to turn the hot tub up high, or something like that. Heat up 
a bathtub in a greenhouse and plant bananas.

DonBarch
Energy Solar

From: Howie Michaelson 
To: Dave Angelini , RE-wrenches

Subject: Re: [RE-wrenches] Inverter output fluctuations
Message-ID:

Content-Type: text/plain; charset="utf-8"

Hi,
I was finally able to get to the site with the light pulsating issue. It
turns out it is that it directly corresponds to the AC coupled SolarEdge
HDwave 6kW inverter.  Moreover, the pulsating gets stronger with higher
output of the SolarEdge inverter (as more sun pouches more current through
the inverter). And the hum of the XW+ very noticeably fluctuates in direct
proportion to light fluxuations. It affects all the lights in the house,
regardless of manufacturer, wattage or age. I did not have an oscilloscope,
but looking at the Hz, it does sag very slightly to 59.9 when the SolarEdge
is producing, down from a rock solid 60 Hz when the SE is not producing.
The output voltage does not change at all.  The fluctuations in both the
lights and the inverter hum immediately stops when the SolarEdge production
is shut off. So it is clearly some interaction between the 2 inverters
causing this issue.

Has anyone dealt with this issue before? Does anyone have any suggestions
for dealing with this, short of replacing the SolarEdge with a Schneider
high voltage Charge Controller?
Thanks,
Howie

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[RE-wrenches] AFCI tripping on SB 4000US-12

[don energysolarnow.com via RE-wrenches]

You should also check the AC wiring. AFCI is detected as radio frequency noise 
from some kind of arc fault. It can be either AC or DC arcing.
I had some AFCI tripping issues that turned out to be loose wiring at the AC 
connector inside the SunnyBoy. It was easily fixed by tightening the screws. 
Since this connector is much closer than the DC wiring it would take less 
faulting to set off the alarm.

Don Barch
Energy Solar

>Friends:
>
> We installed a bunch of Shell SQ-150-PC modules on a ground mount almost
> 20 years ago.  The original SB2500 inverters died so we upgraded to
> SB4000US-21 inverters.  We had some ground fault or AFCI issues a number of
> years ago so we replaced all homeruns with PV wire which resolved the
> problem.
>
> These panels have J-boxes which we interconnected with 1/2? NMLT.  The
> home runs are with PV wire with absolutely no splices and the inter-panel
> jumpers are THWN.
>
> Recently we started getting AFCI disturbances on one inverter.  We
> isolated the fault to one string.  We opened every pull box and panel J-box
> and all of the wiring looks dry, clean and tightly connected.  We inspected
> every panel front and back and see no hotspots or visible corrosion.
>
> I have a megger I have never used.  The homerun is kind of long so maybe
> it has insulation problems.  I could isolate the homerun and megger those
> leads.  I am researching if I can megger PV modules.  It looks like this is
> commonly done.  That looks like my next step.
>
> Does anyone have any ideas on what I should do next? I suppose I could
> start swapping each of the 10 modules in the problem string with panels in
> the non-problem strings, but that seems like a lot of work.
>
> Thanks in advance.
>
> William Miller
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com<http://www.millersolar.com>
>
> CA Lic. 773985

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Re: [RE-wrenches] Envoy R replacement (Dave Tedayan)

[don energysolarnow.com via RE-wrenches]

Hi Dave
You can get a used Envoy-R to talk to the local microinverters, but you will 
not be able to reassign it to the new site. You will have to beg Enphase to do 
this for you. Sometimes this costs money if they think you are reassigning the 
whole system to a new owner.
But why bother? The Envoy-R was superseded by the Envoy-S that can do Wifi and 
talk to the app in AP mode as well.

Don Barch
Energy Solar




Message: 1
Date: Fri, 13 Jan 2023 13:20:25 -0500
From: Dave Tedeyan 
To: RE-wrenches 
Subject: [RE-wrenches] Envoy-R replacement
Message-ID:

Content-Type: text/plain; charset="utf-8"

Hi all,

Does anyone know if you can get any old used Envoy-R (the one in the
attached image) off ebay to replace a failed one? If the used one used to
be associated with another site, would there be issues with installing it
somewhere else?

Cheers,
Dave

--
[image: Logo] <https://www.sungineersolar.com/>
Dave Tedeyan, P.E.
Owner | Sungineer Solar
p: he | him | his
a: 1653 Slaterville Rd. | Ithaca, NY 14850
w: www.sungineersolar.com<http://www.sungineersolar.com> 
<http://www.sungineersolar.com/>
c: (607) 288-2898


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Re: [RE-wrenches] wire management on Qcell AC module

[don energysolarnow.com via RE-wrenches]

No you certainly cannot rely on that tape for long.
We use stainless wire clips like Heyco SunRunner or RevRunner attached to the 
module frame.
https://www.heyco.com/Solar_Power_Components/?sub=wire-management

The QCells AC modules have the microinverters attached so they hang down past 
the module frame so that the support rails cannot be within 12" of the module 
edge. Also it makes attaching the Enphase trunk cable difficult.
I find this inconvenient and no longer use the AC modules.

DonBarch
d...@energysolarnow.com

On Thu, Jun 2, 2022 at 9:37 AM Dave Tedeyan via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Hi All,
>
> I just got some of the Qcell 360w AC modules that have the Enphase
> microinverter factory applied to the back. The module is the half cut cell
> type with the DC leads coming from either side of the middle of the module.
> The modules come with the wires taped to the back of the module. If you
> remove that tape, there appears to be almost no way to properly manage
> those wires. Is that tape meant to just keep the wire on the back of the
> module forever? Would that even last more than a year? I am curious what
> other people have done for these if they have used them or something
> similar. Maybe if you get the rail in the right spot, the wires will just
> sit on the rail...
>
> I realize that we have had a thread on wire management with half cut cell
> modules before, but this is a little different, as I am specifically asking
> about that tape and if anyone knows if it holds up over time.
>
> Cheers,
> Dave
>
> --
> [image: Logo] 
> Dave Tedeyan, P.E.
> Owner | Sungineer Solar
> p: he | him | his
> a: 1653 Slaterville Rd. | Ithaca, NY 14850
> w: www.sungineersolar.com 
> 
> c: (607) 288-2898
> 
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[RE-wrenches] SMA Rapid Shutdown and Secure Power Supply

[don energysolarnow.com via RE-wrenches]

Date: Wed, 27 Apr 2022 12:08:24 -0400
From: Dave Tedeyan 
To: RE-wrenches 
Subject: [RE-wrenches] SMA Rapid Shutdown and Secure Power Supply
Message-ID:

Content-Type: text/plain; charset="utf-8"

Hi All,

The last SMA-41 inverter I commissioned, had the option for SunSpec rapid
shutdown with Secure Power Supply. I just talked to a level one tech who
was not particularly familiar, but told me that with a sunspec rapid
shutdown device like the JMS-F, you can still use the Secure Power Supply
as if there was no rapid shutdown. I had stopped installing the SPS on
rooftop systems, because if losing grid power initiates rapid shutdown,
then you clearly do not have the power to run a SPS. But it sounds like
maybe the inverter has the smarts to wake the solar back up once you flip
the switch to activate the SPS. Can anyone here verify this? Have you done
this, and does it work as expected with no extra hardware needed?

Cheers,
Dave

--
[image: Logo] <https://www.sungineersolar.com/>
Dave Tedeyan, P.E.
Owner | Sungineer Solar
p: he | him | his
a: 1653 Slaterville Rd. | Ithaca, NY 14850
w: www.sungineersolar.com<http://www.sungineersolar.com> 
<http://www.sungineersolar.com/>
c: (607) 288-2898

Hi Dave
I just installed a pair of SB7.7-US41 inverters with the JMS-F Sunspec devices.
The onboard software setup specifies that the Secure Power outlet will not work 
with the JMS-F devices.
These are de-activated when the AC power is off, so even if you connected the 
Secure Power outlet there is no signal to turn on the JMS-F switches.

Don Barch
Energy Solar
707-483-4751
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Re: [RE-wrenches] Aquion troubleshooting

[don]

Hi MacYou did not say what is the history of these batteries or how they are charged.They accept an unusually low charge current;  that means long charge time.They may not be fully charging in a solar day. This would have been apparent from the start of course.DonB
Date: Sat, 24 Jul 2021 11:03:39 -0600
From: Mac Lewis 
To: RE-wrenches 
Subject: [RE-wrenches] Aquion troubleshooting
Message-ID:
	
Content-Type: text/plain; charset="utf-8"

Hey wrenches,

Does anyone have any advice for troubleshooting Aquion batteries? This
particular stack is an Aspen 48M-25.9. They are losing power on a nightly
basis. I'm not seeing much technical literature out there and I'm not
familiar with these batteries.

Are there any common failures? How do you safely open the container to
check parallel strings. It may not be worth digging too deep but I'd be
interested in other opinions and experiences out there. Glad I didn't sell
them to him!

Thanks

--




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Re: [RE-wrenches] Positive grounded inverters for SunPower modules

[don]

I had good luck finding an old but unused Sunny Boy that was easy to set to positive ground.I wonder how many of those are still sitting in warehouses...DonB

Message: 1
Date: Fri, 19 Mar 2021 18:59:51 +
From: Isaac Opalinsky <david.opalin...@sunpower.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] [EXT] Re: Positive grounded inverters for
	SunPower modules
Message-ID:
	<byapr07mb78138b8aa507c6d5d37eb3fe88...@byapr07mb7813.namprd07.prod.outlook.com>
	
Content-Type: text/plain; charset="utf-8"

Don,

Have you contacted SunPower Technical Support yet? If you can?t find what you need from third parties, some SMA inverter options might be available directly from SunPower. I?m assuming the original inverters are long out of warranty, but we may have a compatible SMA inverter available for sale. The disconnects and original mounting plates tend to be harder to come by, however.

The most important thing to ensure expected performance is that you maintain the positively grounded configuration of the array. Galvanically isolated SMA inverters have proven to be the simplest ? reconfigure the jumper and fuse position and then check the voltage and polarity of the array before you recommission.

If you have any difficulty finding what you need, please feel free to contact me directly.

Best Regards,
Isaac Opalinsky | Director, Training & Field Enablement
mobile 443-277-6286 | isaac.opalin...@sunpower.com<mailto:isaac.opalin...@sunpower.com>
[sp_2014_logo_black_orange_CMYK-01]




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[RE-wrenches] Positive grounded inverters for SunPower modules

[don]

We have several older-than-10-year installs with SunPower positively grounded modules and inverters that have failed.  The inverters were branded by SunPower but made by various vendors like PVPowered and Xantrex that aren't around any more. We know if a negative grounded inverter is used with these SunPower 
modules they gather some parasitic charge that inhibits 
normal current flow. I have a few used inverters with negative ground that look like they can be modified to positive ground, with the risk there is some internal software that cannot be adjusted. It looks like a Fronius IG can be changed over with a software adjustment that is actually in the manual. What I'm wondering is whether a new ungrounded inverter can be used with these SunPower modules and keep them operating normally. Does anyone have some pertinent experience with this?ThanksDon Barch
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Re: [RE-wrenches] Aurora PVI 4.2 inverter

[don]

Howie-Sounds like you may need a replacement Aurora inverter.I
 recently replaced one of these Aurora PVI 4.2-OUTD-S-US with a 5 kW 
SunnyBoy to get the Secure Power feature and upgrade to a larger size. This Aurora inverter is vintage 2013 like yours. It was working fine. The owner located in Fairfax CA  would like to sell it off inexpensively. Let me know if you are interested.Don BarchEnergy Solar Date: Tue, 3 Nov 2020 17:52:14 -0500 From: Howie Michaelson  To: RE-wrenches  Subject: [RE-wrenches] Aurora PVI 4.2 inverter Message-ID:  Content-Type: text/plain; charset="utf-8"  Hi All, Does anyone know if any manufacturer is currently responsible for warranty issues of 2013 Aurora PVI 4.2-OUTD-S-US inverters? I don't remember if this is an "ungrounded" inverter, but in any case, if it needs replacement, what are the code rules for replacing it with a different inverter? I believe it isn't required to upgrade to RSD equipment since it is just a repair. Any suggestions for a good replacement that will reasonably match the PVI's input DC voltage specs? Thanks, Howie  *Howie Michaelson**Sun Catcher*  *NABCEP Certified Solar PV Installer?*  *Solar Electric Systems Sales & Service802-272-0004* -- next part -- An HTML attachment was scrubbed... URL:   --  Message: 2 Date: Tue, 3 Nov 2020 18:01:17 -0500 From: Rich Nicol  To: RE-wrenches  Subject: Re: [RE-wrenches] Aurora PVI 4.2 inverter Message-ID:  Content-Type: text/plain; charset="utf-8"  Hi Howie ABB (now Fimer) 1-877-261-1374. They typically require specific photos for warranty. Error code 031 is common. Junk arc fault detector that require upgrade also common. Thanks Rich  Sent from my iPad  > On Nov 3, 2020, at 5:52 PM, Howie Michaelson  wrote: >  > ? > Hi All, > Does anyone know if any manufacturer is currently responsible for warranty issues of 2013 Aurora PVI 4.2-OUTD-S-US inverters?  > I don't remember if this is an "ungrounded" inverter, but in any case, if it needs replacement, what are the code rules for replacing it with a different inverter? I believe it isn't required to upgrade to RSD equipment since it is just a repair. Any suggestions for a good replacement that will reasonably match the PVI's input DC voltage specs? > Thanks, > Howie > Howie Michaelson > Sun Catcher > NABCEP Certified Solar PV Installer? >  > Solar Electric Systems Sales & Service > 802-272-0004 > __


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Re: [RE-wrenches] Commissioning issues with Enphase Ensemble

[don]

With help and a site visit from Adam of Enphase tech support this Ensemble system was successfully brought through commissioning. We had to do a battery black start after it discharged over the weekend. However, functional testing brought up another issue-- in off grid mode the well pump consistently kicks off the two Encharge3 batteries, presumably from inrush current. This is a 3/4 Franklin pump that apparently lacks any capacitor soft start. It is on a 20 amp 2-pole breaker. We measured the operating current at something like 6 amps; the inrush current is likely a multiple of that. The soft starters from Hyper Engineering recommended by Enphase are made for HVAC units with more accessible wires for compressor and fan. This well pump has only two wires. Can anyone recommend a soft starter or variable frequency drive (VFD) starter for a two-wire well pump?ThanksDon BarchEnergy Solar


 Original Message 
Date: Thu, 1 Oct 2020 18:12:39 -0700
From: Louis Woofenden <lo...@woofenden.net>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Commissioning issues with Enphase Ensemble
Message-ID: <12123009-ea4a-ffdc-f927-8e0ac3891...@woofenden.net>
Content-Type: text/plain; charset="utf-8"; Format="flowed"


Hi Don and Wrenches,

I have commissioned four new Ensemble systems over the past two weeks. 
All storage additions to existing PV systems with Enphase 
microinverters. Although there are parts of the process that are a bit 
clunky, we have not had the problems you mention. I followed the 
instructions in the tech brief "Ensemble Commissioning via Installer 
Toolkit 3.0," linked at 
https://enphase.com/en-us/certification-support-program-guidelines 
(direct link to the PDF is 
https://enphase.com/sites/default/files/Tech%20Brief%20-%20Ensemble%20Commissioning%20via%20Installer%20Toolkit%203.0.pdf).

My experience is that each of the four Enpower microgrid interconnection 
devices we've installed started up in passthrough mode, so if input 
breakers are on in the MID, backup loads have had power before 
commissioning is completed, and power has remained on for those backup 
loads even after we turned off the PV and ESS disconnects to wait for 
utility PTO after doing commissioning and functional testing.

It did take us some time to do the Envoy software update before 
commissioning, and the system does require a second trip for functional 
testing after the Encharge battery software updates have been done (up 
to 12 hours). I haven't stuck on site for the Encharge/Enpower software 
updates, but it looks like they are taking 4-6 hours for us, based on 
percentage done by the time I've left the site (system sizes from 10.08 
kWh to 20.16 kWh). Yeah, it's a second trip. I've used the trip to meet 
with electrical inspectors for these first systems.

One "trick" I've used on the Envoy software update is that you once you 
scan in the serial numbers of each Enpower & Encharge with the installer 
toolkit and plug in the cell modem and wireless communications kit, the 
installer toolkit will allow the Envoy software update to work, and you 
can get it taken care of early in the day, while still hanging boxes, 
running conduit, etc.

I would agree that there are definitely parts of the new installer 
toolkit that aren't intuitive. I missed the "edit" button on the devices 
page for a bit (which is not mentioned in the tech brief), and couldn't 
figure out how to increase the device count, for example. I also had to 
try the Envoy update twice for some of these systems, as it threw an 
error code the first time around, so for some of the systems it took 
closer to 45-50 minutes to get the Envoy software update done.

Hope the next one goes more smoothly for you! New products, new 
challenges, I guess.

Best,

Louis Woofenden

d...@energysolarnow.com wrote on 9/30/20 2:59 PM:
> Wrenches-
> I'm having a lot of difficulty commissioning my first Enphase Ensemble 
> installation. This is on a pre-existing microinverter installation. 
> Have been on the phone with tech support several times; each time they 
> forward a Tech Brief about commissioning that has different and 
> slightly conflicting instructions. It seems the order of turning on 
> each box is critical. Because of already-obsolete software that they 
> ship with, the software must be updated before activating the Envoy, 
> Enpower, and Encharge or they will not work.
> And for some reason the Envoy must have both Wifi and cell connection 
> before even starting commissioning, but the slower cell connection is 
> used for software download so it takes up to 12 hours.
> This commissioning must be done on-site using their latest version of 
> Installer Toolkit on a smart phone. Sure, there are buttons in 
> Enlighten's Activation page to add an Enpo

Re: [RE-wrenches] Commissioning issues with Enphase Ensemble

[don]

Thanks for that advice, Louis. Next time I will start the necessary downloads first. This week with a site visit from Enphase tech support we determined the Enpower switch was stuck in an unknown state. This
 was resolved successfully, and now the Enpower switch and Encharge 
batteries are commissioned and functional. Their status and power flow 
can be seen on Enlighten. During 
functional testing we determined that a major cause of the system going 
down when off-grid is that the well pump turn-on surge is too much for 
the two Encharge3 batteries.This issue should be able to be solved by a motor soft starter.  Enphase recommends SureStart from Hyper Engineering. These are made for larger A/C units with access to separate fan and compressor windings so are not appropriate for this two-wire 3/4 hp well pump. Does anyone have a recommendation for a suitable soft start rated at something like 8 amps load, 16 amps surge?Don BarchEnergy Solar


 Original Message 
Subject: Re: [RE-wrenches] Commissioning issues with Enphase Ensemble
From: Louis Woofenden <lo...@woofenden.net>
Date: Thu, October 01, 2020 3:54 pm
To: d...@energysolarnow.com

   Hi Don,  I have commissioned four new Ensemble systems over the past two weeks. All storage additions to existing PV systems with Enphase microinverters. Although there are parts of the process that are a bit clunky, we have not had the problems you mention. I followed the instructions in the tech brief "Ensemble Commissioning via Installer Toolkit 3.0," linked at https://enphase.com/en-us/certification-support-program-guidelines (direct link to the PDF is https://enphase.com/sites/default/files/Tech%20Brief%20-%20Ensemble%20Commissioning%20via%20Installer%20Toolkit%203.0.pdf).  My experience is that each of the four Enpower microgrid interconnection devices we've installed started up in passthrough mode, so if input breakers are on in the MID, backup loads have had power before commissioning is completed, and power has remained on for those backup loads even after we turned off the PV and ESS disconnects to wait for utility PTO after doing commissioning and functional testing.  It did take us some time to do the Envoy software update before commissioning, and the system does require a second trip for functional testing after the Encharge battery software updates have been done (up to 12 hours). I haven't stuck on site for the Encharge/Enpower software updates, but it looks like they are taking 4-6 hours for us, based on percentage done by the time I've left the site (system sizes from 10.08 kWh to 20.16 kWh). Yeah, it's a second trip. I've used the trip to meet with electrical inspectors for these first systems.   One "trick" I've used on the Envoy software update is that you once you scan in the serial numbers of each Enpower & Encharge with the installer toolkit and plug in the cell modem and wireless communications kit, the installer toolkit will allow the Envoy software update to work, and you can get it taken care of early in the day, while still hanging boxes, running conduit, etc.   I would agree that there are definitely parts of the new installer toolkit that aren't intuitive. I missed the "edit" button on the devices page for a bit (which is not mentioned in the tech brief), and couldn't figure out how to increase the device count, for example. I also had to try the Envoy update twice for some of these systems, as it threw an error code the first time around, so for some of the systems it took closer to 45-50 minutes to get the Envoy software update done.   Hope the next one goes more smoothly for you! New products, new challenges, I guess.  Best,  Louis Woofenden   d...@energysolarnow.com wrote on 9/30/20 2:59 PM:   Wrenches-I'm having a lot of difficulty commissioning my first Enphase Ensemble installation. This is on a pre-existing microinverter installation.  Have been on the phone with tech support several times; each time they forward a Tech Brief about commissioning that has different and slightly conflicting instructions. It seems the order of turning on each box is critical. Because of already-obsolete software that they ship with, the software must be updated before activating the Envoy, Enpower, and Encharge or they will not work. And for some reason the Envoy must have both Wifi and cell connection before even starting commissioning, but the slower cell connection is used for software download so it takes up to 12 hours. This commissioning must be done on-site using their latest version of Installer Toolkit on a smart phone. Sure, there are buttons in Enlighten's Activation page to add an Enpower and Encharge, but these do not work "yet". Enphase tech support says they are working on making this a single-day process rather than the current multi-day commissioning. This does not even count the actual hardware installation time. I wou

[RE-wrenches] Commissioning issues with Enphase Ensemble

[don]

Wrenches-I'm having a lot of difficulty commissioning my first Enphase Ensemble installation. This is on a pre-existing microinverter installation.  Have been on the phone with tech support several times; each time they forward a Tech Brief about commissioning that has different and slightly conflicting instructions. It seems the order of turning on each box is critical. Because of already-obsolete software that they ship with, the software must be updated before activating the Envoy, Enpower, and Encharge or they will not work. And for some reason the Envoy must have both Wifi and cell connection before even starting commissioning, but the slower cell connection is used for software download so it takes up to 12 hours. This commissioning must be done on-site using their latest version of 
Installer Toolkit on a smart phone. Sure, there are buttons in 
Enlighten's Activation page to add an Enpower and Encharge, but these 
do not work "yet". Enphase tech support says they are working on making this a single-day process rather than the current multi-day commissioning. This does not even count the actual hardware installation time. I would advise anyone against moving any loads to a new subpanel before the entire system is commissioned and operating. As of now I have an Enpower that mistakenly thinks it is off-grid when the grid is present, so it has told the Envoy to shut down the PV microinverters and batteries. These are relay controlled, therefore it is not possible to have them connected without software control.  It has already committed the major crime of shutting down the backed-up loads while the grid is still present. Enphase is working on it, but seem to be developing software on the fly. I suppose their integration process has been hit hard by pandemic distancing, and they are all working remotely. Has anyone else had a successful experience commissioning an Ensemble? I'd like to hear about the doos-and-don'ts. Don Barchd...@energysolarnow.com
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Re: [RE-wrenches] Skybox

[don]

Hi DaveThe 5kW limit is the inverter power rating; that's all the solar or battery power it can generate. Asking for more than that won't trip a breaker, the voltage will start to sag. The grid breaker is 50 amps, so when the grid is present the loads should be able to draw (50 amps) x (240 volts) = 12 kWatts from the grid, not from the inverter itself.Yes you have to be conservative as to how many loads can be backed up. Typically that's not the whole house; critical loads are moved to a new critical load sub panel. The SkyBox does not have a built in bypass, that must be added if it is needed. Don BarchEnergy Solar


 Original Message 
Subject: Re: [RE-wrenches] Skybox
From: Dave Tedeyan <dtede...@taitem.com>
Date: Wed, May 06, 2020 6:30 pm
To: d...@energysolarnow.com
Cc: "re-wrenches@lists.re-wrenches.org"
<re-wrenches@lists.re-wrenches.org>

Is the 5kw limit and no surge capacity for the backed up AC loads only when operating off grid? If you occasionally trip a breaker during the relatively rare times when the grid is out (around here at least) it is not such a big deal. But if you had to deal with that daily, you would have to be way more conservative as to what loads are allowed to be backed up.Also, is there an inverter bypass built into the BOS enclosure, or do you need to wire up a separate one in case of inverter failure.Cheers, DaveDave Tedeyan, PESenior Engineer | Taitem Engineering, PC110 South Albany Street | Ithaca, NY 14850o. 607.277.1118 x121  f. 607.277.2119www.taitem.comSolar • Sustainability • Energy • DesignCertified B-Corporation since 2013On Mon, May 4, 2020 at 8:24 PM <d...@energysolarnow.com> wrote:I'm finding the SkyBox to be reliable hardware, if you don't need big surge capability. But the software is still in flux. I have had to reject software updates that froze the system, going back to the previous version to bring it back again. One issue is that AC coupling does not work with multiple Skyboxen, unlike with older Radians. Another huge problem that seems to be software related is that dual SkyBoxen with different sized solar arrays discharge their battery banks at different rates. This becomes an issue in multiple day grid outages like we now expect in north CA fire season.  You'd think the SkyBox master-slave relationship would allow them to coordinate, but this causes the one with a smaller solar array to run down it's battery sooner, faulting the system causing a complete shutdown of both SkyBoxen. OutBack says they are not fixing this, so I'm looking at SolArk for systems larger than 5 kW. Don BarchEnergy Solar    Original Message  Subject: RE-wrenches Digest, Vol 13, Issue 124 From: re-wrenches-requ...@lists.re-wrenches.org Date: Mon, May 04, 2020 2:40 pm To: re-wrenches@lists.re-wrenches.org  Send RE-wrenches mailing list submissions to re-wrenches@lists.re-wrenches.org  To subscribe or unsubscribe via the World Wide Web, visit http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org or, via email, send a message with subject or body 'help' to re-wrenches-requ...@lists.re-wrenches.org  You can reach the person managing the list at re-wrenches-ow...@lists.re-wrenches.org  When replying, please edit your Subject line so it is more specific than "Re: Contents of RE-wrenches digest..."   When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message.   Today's Topics:  1. Skybox (Dave Tedeyan) 2. Re: Skybox (Jerry Shafer) 3. Re: Skybox (jay) 4. Re: Skybox (penobscotso...@midmaine.com)   --  Message: 1 Date: Sun, 3 May 2020 21:32:38 -0400 From: Dave Tedeyan <dtede...@taitem.com> To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Subject: [RE-wrenches] Skybox Message-ID: <ca+cq0butzbbg84gavcjoyq6ahpgz6ctwy_i_eczepubrfe7...@mail.gmail.com> Content-Type: text/plain; charset="utf-8"  Hi All,  Does anyone have experience using Outback's Skybox inverter? I have someone interested and am curious to hear if people have had luck with them and if they are reliable.  Also, I've been seeing promo material for Fronius' Gen 24 Plus inverter, which looks like it fills the same niche. Are those even available for purchase yet? If so, does anyone have experience with these?  Cheers, Dave  *Dave Tedeyan, PE* Senior Engineer | Taitem Engineering, PC  110 South Albany Street | Ithaca, NY 14850 o. *607.277.1118 x121* f. 607.277.2119 www.taitem.com  Solar ? Sustainability ? Energy ? Design Certified B-Corporation since 2013 -- next part -- An HTML attachment was scrubbed... URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20200503/bd47522b/attachment-0001.html>;  -

Re: [RE-wrenches] Rapid Shutdown Compliance Secure Power

[don]

Thanks for the suggestion of using a SPDT; but there is a who's-on-first problem there. Normally the switch supplies utility power to the RS controller. When that goes down, we want AC from the Secure Power. But that won't activate until the inverter gets solar power, which is now cut off by the RS system that needs AC to activate it firstDon BarchEnergy Solar
Date: Tue, 5 May 2020 08:35:51 -0400
From: Tump <t...@swnl.net>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Rapid Shutdown Compliance
Message-ID: <7273560e-f55b-4007-824e-fd6bb740a...@swnl.net>
Content-Type: text/plain; charset="utf-8"

How about a SPDT switch, all one is doing is supplying AC voltage from the utility,  (powering the MLPE box's Ac to Dc converter) their utility or SSP from the SB's utility. 
> On May 4, 2020, at 8:04 PM, <d...@energysolarnow.com> <d...@energysolarnow.com> wrote:
> 
> Many customers ask about keeping power alive when the grid is down. Besides battery backup, I advocate the Secure Power feature of SunnyBoy inverters.
> But the problem with MLPE is that it is incompatible with Secure Power. When the grid goes down the MLPE disconnect each solar module's DC feed. So when the Secure Power activation switch is thrown there is no DC to power it up, even if the Secure Power output is fed to the MLPE power feedin.
> So I have only been able to install SunnyBoy Secure Power on existing systems without Rapid Shutdown MLPE. 
> 
> Does anyone have a work around for this, short of installing a separate small battery backed inverter to keep the MLPE alive?
> 
> Don Barch
> Energy Solar
> ___
> List sponsored by Redwood Alliance



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[RE-wrenches] Skybox

[don]

I'm finding the SkyBox to be reliable hardware, if you don't need big surge capability. But the software is still in flux. I have had to reject software updates that froze the system, going back to the previous version to bring it back again. One issue is that AC coupling does not work with multiple Skyboxen, unlike with older Radians. Another huge problem that seems to be software related is that dual SkyBoxen with different sized solar arrays discharge their battery banks at different rates. This becomes an issue in multiple day grid outages like we now expect in north CA fire season.  You'd think the SkyBox master-slave relationship would allow them to coordinate, but this causes the one with a smaller solar array to run down it's battery sooner, faulting the system causing a complete shutdown of both SkyBoxen. OutBack says they are not fixing this, so I'm looking at SolArk for systems larger than 5 kW. Don BarchEnergy Solar


 Original Message 
Subject: RE-wrenches Digest, Vol 13, Issue 124
From: re-wrenches-requ...@lists.re-wrenches.org
Date: Mon, May 04, 2020 2:40 pm
To: re-wrenches@lists.re-wrenches.org

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Today's Topics:

   1. Skybox (Dave Tedeyan)
   2. Re: Skybox (Jerry Shafer)
   3. Re: Skybox (jay)
   4. Re: Skybox (penobscotso...@midmaine.com)


--

Message: 1
Date: Sun, 3 May 2020 21:32:38 -0400
From: Dave Tedeyan <dtede...@taitem.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] Skybox
Message-ID:
	<ca+cq0butzbbg84gavcjoyq6ahpgz6ctwy_i_eczepubrfe7...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Hi All,

Does anyone have experience using Outback's Skybox inverter? I have someone
interested and am curious to hear if people have had luck with them and if
they are reliable.

Also, I've been seeing promo material for Fronius' Gen 24 Plus inverter,
which looks like it fills the same niche. Are those even available for
purchase yet? If so, does anyone have experience with these?

Cheers,
Dave

*Dave Tedeyan, PE*
Senior Engineer | Taitem Engineering, PC

110 South Albany Street | Ithaca, NY 14850
o. *607.277.1118 x121*  f. 607.277.2119
www.taitem.com

Solar ? Sustainability ? Energy ? Design
Certified B-Corporation since 2013
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Message: 2
Date: Sun, 3 May 2020 18:46:09 -0700
From: Jerry Shafer <jerrysgarag...@gmail.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Skybox
Message-ID:
	<camufgmwachaodr+puaxlrude8igsxd7mkpc+l-hnopqwbwx...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Dave
I have used the radian and started using the skybox, it works well and is
as simple as it gets to install. My personal experience with fronius is not
good with there grid tie units. Outback has been around in the off grid
environment and is my go to, but hey that's just me
Jerry

On Sun, May 3, 2020, 6:32 PM Dave Tedeyan <dtede...@taitem.com> wrote:

> Hi All,
>
> Does anyone have experience using Outback's Skybox inverter? I have
> someone interested and am curious to hear if people have had luck with them
> and if they are reliable.
>
> Also, I've been seeing promo material for Fronius' Gen 24 Plus inverter,
> which looks like it fills the same niche. Are those even available for
> purchase yet? If so, does anyone have experience with these?
>
> Cheers,
> Dave
>
> *Dave Tedeyan, PE*
> Senior Engineer | Taitem Engineering, PC
>
> 110 South Albany Street | Ithaca, NY 14850
> o. *607.277.1118 x121*  f. 607.277.2119
> www.taitem.com
>
> Solar ? Sustainability ? Energy ? Design
> Certified B-Corporation since 2013
> ___
> List sponsored by Redwood Alliance
>
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>
> Change listserver email address & settings:
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Re: [RE-wrenches] Rapid Shutdown Compliance

[don]

Many customers ask about keeping power alive when the grid is down. Besides battery backup, I advocate the Secure Power feature of SunnyBoy inverters. But the problem with MLPE is that it is incompatible with Secure Power. When the grid goes down the MLPE disconnect each solar module's DC feed. So when the Secure Power activation switch is thrown there is no DC to power it up, even if the Secure Power output is fed to the MLPE power feedin. So I have only been able to install SunnyBoy Secure Power on existing systems without Rapid Shutdown MLPE. Does anyone have a work around for this, short of installing a separate small battery backed inverter to keep the MLPE alive? Don BarchEnergy Solar
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Re: [RE-wrenches] Name that Racking

[don]

Yes that's SnapNRac ground mount rail, now discontinued. The sliding nuts are compatible with ProSolar, but be aware that SnapNRac midclamps are 1/2" wide vs. ProSolar at 5/8" wide, so you will have to use them in pairs to get the modules to line up. DonBEnergy Solar


 Original Message 
Subject: RE-wrenches Digest, Vol 13, Issue 122
From: re-wrenches-requ...@lists.re-wrenches.org
Date: Thu, April 30, 2020 2:41 pm
To: re-wrenches@lists.re-wrenches.org

Send RE-wrenches mailing list submissions to
	re-wrenches@lists.re-wrenches.org

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	http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org
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When responding to posts within the Digest, be sure to restore the Subject: line to the original, and please edit out any extraneous lines from the quoted message.
 

Today's Topics:

   1. Re: Name that Racking (Tump)
   2. Re: Rapid Shutdown Compliance (Dave Tedeyan)
   3. Re: Rapid Shutdown Compliance (Harry Mahon)


--

Message: 1
Date: Thu, 30 Apr 2020 12:20:28 -0400
From: Tump 
To: RE-wrenches 
Subject: Re: [RE-wrenches] Name that Racking
Message-ID: 
Content-Type: text/plain; charset="utf-8"

Snap n rac series 200
> On Apr 30, 2020, at 12:17 PM, Dave Tedeyan > wrote:
> 
> Hi All, 
> Does anyone know what kind of racking is shown in the attached photos?
> I just need to get a few midclamps to add a couple modules, but have not seen it before.
> Thanks!
> -Dave
> 
> Dave Tedeyan, PE
> Senior Engineer | Taitem Engineering, PC
> 
> 110 South Albany Street | Ithaca, NY 14850
> o. 607.277.1118 x121  f. 607.277.2119
> www.taitem.com www.taitem.com/>
> 
> Solar ? Sustainability ? Energy ? Design
> Certified B-Corporation since 2013
> sm.JPG>sm.JPG>___
> List sponsored by Redwood Alliance
> 



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[RE-wrenches] OK, so what iwould happen if I do this...

[don]

You wrote that you would connect the Exeltech to just one of the service phases. But most GT inverters are 240 and require both phases. Is yours different? You did not mention which model it is. Also, as Kent Osterberg mentioned, the Exeltech will not charge its batteries from the AC output. Your scheme with the PLC controlling an SCR leaves unaddressed how any charge current gets directed into the batteries to allegedly raise their voltage. Is there a charger somewhere in this scheme?You still need some way to charge batteries from solar. How about connecting a charge controller to some of the solar panels?Don BarchEnergy Solar


 Original Message 
Subject: RE-wrenches Digest, Vol 13, Issue 59
From: re-wrenches-requ...@lists.re-wrenches.org
Date: Sun, March 01, 2020 2:19 pm
To: re-wrenches@lists.re-wrenches.org

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Today's Topics:

   1. OK, so what iwould happen if I do this... (Mark Frye)
   2. Re: OK, so what iwould happen if I do this... (frenergy)
   3. Re: OK, so what iwould happen if I do this... (Kent Osterberg)
   4. Re: OK, so what iwould happen if I do this... (Jerry Shafer)


--

Message: 1
Date: Sat, 29 Feb 2020 15:27:32 -0800
From: Mark Frye <ma...@berkeleysolar.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] OK, so what iwould happen if I do this...
Message-ID: <93731c38-40b5-7c63-1d74-a879fbdd9...@berkeleysolar.com>
Content-Type: text/plain; charset=utf-8; format=flowed

I have 2kw of grid tied PV on my house.

Suppose I:

- Open the main breaker to disconnect from the grid

- I open the PV breaker

- I connect a small good quality inverter like an Exeltech XP 500 to one 
of the phases of the service (120 VAC)

- I put a small battery pack, 100 AH at 24 VDC on the inverter

OK so far, I could run some small loads for a relatively short period of 
time before the batteries get low

-I have a PLC with an AD input and DA output. On the input I measure the 
battery voltage, on the output I control a SCR. The SCR controls a 2kw 
immersion heater sitting in a big bucket of water. The PLC has a scan 
time of 2 mS and I program it to increase the duty cycle of the SCR as 
voltage of the battery rises above 24 VDC.

OK so far nothing has really changed from above.

- I close the PV breaker, the GT inverters see the battery inverter, 
sync and connect after five minutes.

Voila, I can run house loads from 0 to 2kw with my existing GT PV with 
the balance of energy dumped as needed to the immersion heater.

Right?

Mark Frye



--

Message: 2
Date: Sun, 1 Mar 2020 06:26:27 -0800
From: frenergy <frene...@psln.com>
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [RE-wrenches] OK, so what iwould happen if I do this...
Message-ID: <c97234cd-4441-34d7-740c-51f07837b...@psln.com>
Content-Type: text/plain; charset=utf-8; format=flowed

Mark,

 ??? ??? ??? OR, you change-out your inverter to an SMA with Secure 
Power Supply and during grid power outage, while there is some sun on 
the panels, you would have up to 2KW of 120VAC power on the SPS circuit 
by just flipping a switch. We usually install a 4X outdoor box with a 
120 VAC outlet ganged with a switch right under the inverter and let the 
customer run the power to the : frig, lights, battery charger, TV or 
whatever during an outage, though some romex could be run to close to 
the frig.

Bill

Feather River Solar Electric
Bill Battagin, Owner
4291 Nelson St.
Taylorsville, CA 95983
530.284.7849
CA Lic 874049
www.frenergy.net

On 2/29/2020 3:27 PM, Mark Frye wrote:
> I have 2kw of grid tied PV on my house.
>
> Suppose I:
>
> - Open the main breaker to disconnect from the grid
>
> - I open the PV breaker
>
> - I connect a small good quality inverter like an Exeltech XP 500 to 
> one of the phases of the service (120 VAC)
>
> - I put a small battery pack, 100 AH at 24 VDC on the inverter
>
> OK so far, I could run some small loads for a relatively short period 
> of time before the batteries get low
>
> -I have a PLC with an AD input and DA output. On the input I measure 
> the battery voltage, on the output I control a SCR. The SCR 

Re: [RE-wrenches] Xantrex SW 4048 grid tie mystery

[don]

Hi DaveYour experience here closely resembles mine on at least two jobs with these inverters. When the AC1in light blinks the inverter is no longer connected to the grid. The loads are running off battery power, but this will be short term in winter weather. I have a VFXR3648A in my truck now to replace an SW4048 that has lost the ability to connect to the grid.  It killed the batteries in rainy weather, so they are being replaced as well. If you set the terminals of your meter from the AC1 input to the Load output you will see the voltage phase difference. If they are in phase the voltage difference is zero. In my case this voltage drifts from 0 to 240 over a period of 15 secs or so, indicating the lack of sync.  I have not found anyone who repairs these old modified square wave inverters. The old SW4048 should still be good for off grid use. If anyone wants it let me know. Located in Bolinas, CA. At least I can go surfing after service calls thereDon BarchEnergy Solar


 Original Message 
Subject: RE-wrenches Digest, Vol 12, Issue 362
From: re-wrenches-requ...@lists.re-wrenches.org
Date: Tue, December 24, 2019 2:34 pm
To: re-wrenches@lists.re-wrenches.org

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Today's Topics:

   1. Re: Xantrex SW 4048 grid tie mystery (Dave Tedeyan)


--

Message: 1
Date: Tue, 24 Dec 2019 15:14:18 -0500
From: Dave Tedeyan <dtede...@taitem.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Xantrex SW 4048 grid tie mystery
Message-ID:
	<ca+cq0bvfmczx5vakqo-1vhztqadvsob42hkg1--7no9emrr...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Hi All,
So I went back today and updated all the programming. There was actually
lots of sun too (a rare event in upstate NY this time of year)!

The inverters have not yet had any issues with powering the backed up loads
so far. But there have been issues with selling back to the grid. One
inverter was selling just fine, with the sell current right around the max
sell setting. The other inverter would very quickly ramp up its sell and go
way past the setting (set at 30A) and start selling at up to about 60A, and
then would stop selling (but continue to power the backed up loads. When
selling, the AC1 in good light would stay on green solid. Then when the one
inverter would stop selling, that light would flash. Then 5 minutes or so
later, it would click a bunch of times, start selling, and within about 10
seconds overshoot the setting again and kick off.

I tried Tumps suggestion of removing the black jumper. When I did that in
each inverter, neither one would sell, but they would continue to power the
backed up loads.

I also tried bypassing the GTI on the inverter that was having selling
issues. When I did that, the AC1 in good light never came on at all, even
though I verified AC voltage on the input. It never started selling, but it
would at least continue to power the backed up loads. I only had it like
this for about 15 minutes before I had to leave the site, so will be
checking in on the system in the coming days. Last time I was there and
fired it up, it worked fine to begin with and it was not until many hours
later that the issues with powering the backed up loads started appearing.

Cheers,
Dave

*Dave Tedeyan, PE*
Senior Engineer | Taitem Engineering, PC

110 South Albany Street | Ithaca, NY 14850
o. *607.277.1118 x121*  f. 607.277.2119
www.taitem.com

Solar ? Sustainability ? Energy ? Design
Certified B-Corporation since 2013


On Sun, Dec 22, 2019 at 5:11 PM b...@midnitesolar.com <b...@midnitesolar.com>
wrote:

>
> Forgot to say that if the inverters ARE grid tied, then they will NOT
> drift around in phase and will
>
> be synchronized  and therefore will stay in sync and be passing through
> from grid to output.
>
> boB
>
>
>
> On 12/22/2019 12:57 AM, Jerry Shafer wrote:
>
> Well l would start simple and get a sync cable and make sure that they are
> al least staying g in correct phasing, then look closely at the
> programming, look at the grid voltages and settings, take it out of IEEE
> for test purposes only, you might find out you have a board that's ou

[RE-wrenches] expanding OutBack SkyBox

[don]

Hi WrenchesI have installed an OutBack SkyBox for a customer with 13 290 watt solar panels feeding it. At
 this point the Skybox is installed without batteries connected the main service panel in his garage, with a 100 amp breaker feeding a
 house subpanel. My plan has been to put in a smaller critical-load subpanel in the house, as well as one in the garage to support the well pump. When we went into the details and he realized all the house
 loads could not be completely backed up by the 5kW Skybox, he halted to
 reconsider.I'm 
thinking it might be possible to expand the battery backup 
capacity with something like an OutBack VFXR3048 or perhaps a Radian 
slaved to the SkyBox. This additional 
inverter would be idle most of the time. The SkyBox documentation 
indicates it can handle more than one SkyBox; how about another VFX 
inverter?Also, when 
the SkyBox does load shaving using stored battery power to feed loads after dark, is it
 feeding the critical loads panel only or all loads in the main panel? 
If it is feeding all loads, how does it know how much current is for 
loads and how much it is selling back to the grid, lacking CT's to
measure this? Thanks for any insight you can offer.DonBarchd...@energysolarnow.com
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Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[don]

Yes this is an interesting case, as are the debug suggestions given. The wire pairs working out of metal conduit point strongly at either ground faulting or inductive coupling. You seem to have eliminated the obvious wiring issues like polarity and grounding. Since you have a working system next door and you are already putting in the 
hard work of swapping inverters and wires, it is worth trying to 
swap the inverter from that working system with the non-working one. 
This would either indict or eliminate the inverter as the culprit. It is worth noting that the TrinaSmart modules with Tigo Maximizers are quite capable of being the source of the problem. They attempt to do MPPT at the module level, and can conflict with the inverter's attempts at MPPT. We have had problems with other inverter brands to the extent that power production was impaired, although not as bad as your complete shutdown. It was necessary to use the inverter setup options to shut off MPPT. If Solectria allows this it is worth trying. Also I have had problems with Tigo Maximizers on mismatched strings shutting down one string completely to "maximize" others. You may be seeing the effect of communication problems from the maximizer wireless controller. Try disabling them if possible by shutting down their controller with its secret software.I'm guessing that plain dumb modules with a plain dumb inverter would not be suffering this shutdown problem. Something in your system is too smart for your own good.Don BarchEnergy Solar


 Original Message 

-Original Message-
From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On
Behalf Of Matt Partymiller
Sent: Wednesday, September 07, 2016 4:46 PM
To: re-wrenches@lists.re-wrenches.org
Subject: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in
Conduit/Inverter Turning Off/On Rapidly

Wrenches,

One of our systems is having an issue I have not encountered before where
the inverter switches between nighttime mode and interconnection every few
seconds.  I am hoping for some technical wisdom from the community.

We have an array of 20 TrinaSmart modules in two strings of 10.  The array
is connected to a Solectria 3.8 kW inverter.  The conduit run is simple, all
four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the
Solectria inverter where the conduit switches to 1" LFMC before entering the
inverter.  The run is about 20', straight down the side of the wall before
hitting the inverter.  A 600V jacketed communications wire was also in the
conduit but has since been removed and run separately.

Our inverter is starting up, running for a few seconds, giving a low voltage
error, briefly showing nighttime mode, then going into startup mode again.
Solectria was gracious enough to send us a new inverter but we have the
exact same issue.  They tell us their error codes (266, 274) indicate 0
volts.  The transition between low voltage error and startup is almost
instant.  Basically we have 20 seconds of start up, 5 seconds of run, 5
seconds of error then repeat.  This is not a grid problem, the identical
system next door works fine.

In the process of troubleshooting, our technician pulled all four homerun
wires out of our conduit and meggered them.  They all tested fine so he
connected to the inverter.  The inverter worked fine.  The technician
verified grounding of the array and conduit, pulled new homeruns back
through the conduit, and reconnected to the inverter.  He had the same error
as before.

He connected each string separately to the inverter by removing the string
fuses.  Either string will operate fine independently.  With string one in
conduit and either homerun of string two in conduit (but not both) the
inverter operates fine.  With string two in conduit but string one outside
of conduit, the inverter does not operate.

I was certain the error had something to do with homerun roof wiring so I
went out with the technician and removed and checked pretty much every
module.  Everything appears fine, all connections solid, all homeruns have
been remade at least once at this point.  Now I am stumped and lack the
technical knowledge to diagnose the problem.  I would be extremely grateful
if an esteemed wrench can provide technical support/advice.

Thanks,

Matt




Matthew Partymiller
Solar Energy Solutions LLC
(877) 312-7456
m...@solar-energy-solutions.com


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Re: [RE-wrenches] Buck-Boost transformer to mitigate high voltage drop?

[don]

Howard- Any voltage drop at the house will be a function of current drawn by the house load. Shut off most loads and there will be minimal voltage drop.  If there was a low voltage issue now before solar is installed, there would be symptoms like florescent lights not working well. That's why they flicker when a big motor kicks on nearby.  A transformer could be used to boost the voltage to the house, but that assumes more or less constant load. When the house load is low there is minimal voltage drop and the boosted voltage may become too high. The utility service transformer may have different wire taps to adjust its output voltage as well. But again, this assumes more or less constant load. When there are long wire runs it is more common to use a pair of transformers, one at the utility drop and one at the house, to boost (or step up) the voltage at the service drop end to, say, 480 with a 2:1 transformer. That is, the ratio of number of primary to secondary windings is 2:1. Then at the house another matching transformer bucks (steps down) the voltage back to 240. The current in the long wire run is cut in half, and so is voltage drop. This boosted voltage can be higher-- thousands of volts are not uncommon on ranch properties with miles-long wire runs. A solar inverter senses the voltage at it's connection point, and raises it's voltage a couple volts higher to push solar current into the wire. If there is voltage drop in the wire, the solar inverter must raise it's voltage even higher to overcome voltage drop and still be a couple volts above the grid. If voltage drop is severe, the inverter will sense that it's voltage is getting too high out of range and fault with a grid voltage error. Grid voltage is not changing, inverter voltage is. For example, we had an inverter sited at a 10 KW array connected to a garage with 200' of existing 6 AWG AL buried wire. The attendant voltage drop from nearly 40 amps solar current caused the inverter to raise it's own voltage so much to overcome voltage drop that it faulted. It was necessary to tweak the software settings to allow the voltage range to be extended.When your client's 20 KW solar inverter is sited at the house, any solar current will first be consumed by the house loads. This reduces current through the long wire run and so reduces voltage drop. When the solar current matches the house loads, no current flows through the long wire run and there is no voltage drop. Everyone is happy, except the utility company who now doesn't get to sell energy.Excess solar current not consumed by house loads will run back through the long wire to the utility grid, causing some voltage drop. This must be overcome by the inverter raising it's voltage to still be a couple volts over grid-voltage-plus-voltage-drop. Without running the numbers I suspect that the less-than-40 solar amps you may run into 4/0 AL wire will not be a problem. You will want to measure the voltage at the house under low and maximum load conditions. If the load is at max when the sun shines, a solar inverter will tend to help alleviate any low voltage issue at the house, as Ray W. wrote. Don BarchEnergy Solar
Date: Tue, 16 Aug 2016 14:23:27 -0600
From: Ray Walters <r...@solarray.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Buck-Boost transformer to mitigate high
	voltage drop?
Message-ID: <c0339c2a-4d02-f64c-2512-fb1a7bbc0...@solarray.com>
Content-Type: text/plain; charset="windows-1252"; Format="flowed"

My guess is that in your case the GTPV will just help alleviate the volt 
drop situation.  I wouldn't start adding transformers, etc until you are 
having a problem.  Put in the contract that this extra cost may be 
necessary for proper function, but I would keep it as a backup.  Based 
on the numbers you just mentioned, you would only be selling a surplus 
of 30 amps, and the existing wire should be adequate for that.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 8/16/2016 1:16 PM, Howard Arey wrote:
>
> Answers to all:
>
> No ? I did not measure voltage at the house. Right now, only an 
> assumption of voltage drop based on my perception of what ?typical? 
> loads might be on this 150-amp service. I wasn?t expecting to see such 
> small wires for such a long run from transformer to house when I 
> showed up there without a voltmeter. He is a heavy user, using 6,000 
> kwh in some months
>
> We?re looking at a 20KW system (he has some other expansion 
> requirements, he has the roof space, and the need.) I roughly estimate 
> that he?ll use onsite 40-50 amps of the 82 amps at peak inverter power 
> output.
>
> Interesting to hear of one transformer response and hope to learn more 
> on that, too.
>
> *Howard ?Scot? Arey*
>

[RE-wrenches] CA wrenches

[don]

Bill- When there is rebate money involved the utilities like to require a Revenue Grade meter. The list of eligible meters is on the Go Solar site http://www.gosolarcalifornia.ca.gov/equipment/system_perf.phpSMA's Sunny Beam and WebBox monitors are on the list. Give the customer a web based monitor and then you can see the generation too. Don BarchEnergy Solar

Date: Mon, 1 Aug 2016 20:04:36 -0700
From: frenergy <frene...@psln.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] CA wrenches
Message-ID: <c2aabcd1-65d4-b5d5-a3d5-4771e7fe7...@psln.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

California Wrenches,

 One of my utilities which is still offering rebates for 
grid tie went to the Go Solar California website to see that the newest 
SMA TL inverters (5.0 and 6.0) are on the "approved" list which of 
course it is.  However, in the "Approved built-in meter" column shows a 
"NO" for it.  My utility wants me to add an additional, separate meter 
to show KWhr power production.I've talked with SMA about this and 
the onboard monitor gives KWhrs and they've showed me their docs for it, 
but my utility is still using the fact that the Go Solar site says no.

How have others dealt with this or is it just my utility that's made an 
issue of this?

Thanks,

Bill

Feather River Solar Electric
Bill Battagin, Owner
4291 Nelson St.
Taylorsville, CA 95983
530.284.7849
CA Lic 874049
www.frenergy.net






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Re: [RE-wrenches] 480 single phase delta

[don]

Hi Jay -Usually 408 delta will have 3 legs.  See https://en.wikipedia.org/wiki/Three-phase_electric_powerUnlike Wye, the neutral is center tapped from the winding between two of the legs.The third is a hi leg or "stinger" leg that is 1.5 times the others voltage to neutral.Sounds like what you have is two of three legs with a center tapped neutral; the the hi leg is probably around somewhere on site. If you can find it then a 3-phase inverter will work. Otherwise, as mentioned you will need a transformer to get 240 across the legs you have. But 10kW of solar will unbalance the phases. Best to find that third leg and use a 3-phase inverter. I have used the Fronius IG Plus 11.4 for this with good results. Don BarchEnergy Solar
Date: Fri, 29 Apr 2016 08:03:26 -0700
From: jay <jay.pe...@gmail.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] 480 single phase delta
Message-ID: <b75c4e4a-5eb4-49d0-a7d4-9bdee1e40...@gmail.com>
Content-Type: text/plain; charset="utf-8"

HI Jerry and all,

I?m sorry if I confused the issue.  
I haven?t seen this, I?m doing the research for a friend.  
It has been measured at numbers  provided.  480 line to line, 240v line to neutral, 2 hots wires, not 3.

The client has been told by 3 different installers that its impossible system to do.  
And as the experts here have provided, thats just not true.

Thanks for the input.  

jay


> On Apr 28, 2016, at 6:58 PM, Jerry Shafer <jerrysgarag...@gmail.com> wrote:
> 
> I cant say l have seen a single phase delta, open delta, use two of the three legs but not on pumps, can someone explain,  what am l missing as the term delta is three points
> Jerry
> 
> On Apr 28, 2016 3:50 PM, "Jay" <jay.pe...@gmail.com ><mailto:jay.pe...@gmail.com>> wrote:
> Great inverter but this is single phase. 
> Jay
> 
> Sent from my iPhone
> 
> On Apr 28, 2016, at 3:10 PM, jerrysgarage01 <jerrysgarag...@gmail.com ><mailto:jerrysgarag...@gmail.com>> wrote:
> 
>> What about an SMA Tri Power inverter
>> Jerry
>> 
>> 
>> Sent via the Samsung Galaxy S? III, an AT&T 4G LTE smartphone
>> 
>> 
>>  Original message 
>> From: Chris Mason
>> Date:04/28/2016 8:52 AM (GMT-10:00)
>> To: RE-wrenches
>> Subject: Re: [RE-wrenches] 480 single phase delta
>> 
>> You will use a 240:480v step up transformer
>> 
>> On Apr 28, 2016 14:17, "jay" <jay.pe...@gmail.com ><mailto:jay.pe...@gmail.com>> wrote:
>> HI All,
>> 
>> I have a question from a person wanting to do a intertie on a commercial water pumping site with
>> 
>> 480v single phase delta configuration.
>> 
>> PV will be in the 10kw range.
>> 
>> Anybody have an idea of what equipment will work for this?
>> 
>> 
>> 
>> thanks
>> 
>> jay
>> 
>> peltz power




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Re: [RE-wrenches] LiFePO4; WAS Availability of Powerwall Batteries

[don]

Thanks for sharing your experience with these batteries, Dan.I have similar SOC issues with an off-grid customer who has the Aquion Hybrid Ion batteries.It has difficulty reaching full charge from solar, requiring the genny to kick on each morning even in the summer.This is even worse in cold winter weather.Your explanation of the change in Peukert's exponent above 80% SOC with NiFe batteries sounds like what is happening here as well. Do you have any experience with Aquion batteries that you can share?ThanksDon Barch Energy Solar d...@energysolarnow.com
Message: 2
Date: Mon, 25 Jan 2016 15:51:26 -0700
From: Dan Fink 
To: RE-wrenches 
Subject: Re: [RE-wrenches] LiFePO4; WAS Availability of Powerwall
	Batteries
Message-ID:
	
Content-Type: text/plain; charset="utf-8"

Hello Mark;
My NiFes went in last March, I'm almost at a year living with them off the
grid.
To avoid writing a novel here I'll group my comments into Oddities,
Advantages and Disadvantages.

Advantages:
~ at least 25 year lifespan
~ 10 year warranty
~ Can add more parallel strings at any time/age, just drain and replace
electrolyte of old batteries
~ 80% depth of discharge no problem, so can size smaller amp-hour capacity

Oddities:
~ alkaline electrolyte, neutralize spills and clean tops with white vinegar
~ Specific gravity of electrolyte does not change with state of charge so a
hydrometer is useless
~ Charge / discharge efficiency changes greatly with state of charge.
Sometimes my Magnum ME-BMK amp hour meter matches the Midnite Whizbang Jr
exactly, sometimes they are way off from each other. For ground truth, the
state of charge vs. voltage curve from the battery manufacturer seems right
on, not counting false readings when the batteries are not at rest for a
couple hours.
~ Fooling PV MPPT charge controllers into dealing with NiFes involves
setting a very long and high Absorb voltage
~ Charge efficiency is great up to 80% state of charge, but after that
drops way off. Above 80% SOC these batteries want to see 1.65v per cell to
really fill up. No problem for modern MPPT PV controllers, but-
~ Some inverter / chargers (Magnum here) freak out and shut down at 1.6v
per cell, so the solution from the battery manufacturer is-
~ Run fewer cells during times of year when charging is frequent from the
generator, put the extra cells back in the string during times of year when
the charging is mostly PV. Sitting uncharged does not damage these "extra"
cells.
~ So I am running a 10.8v battery bank right now, will bring it back to 12v
this spring. No big deal, but does affect inverter surge capacity. Would
not be as much of a problem at 24v or 48v.
~

Disadvantages:
~ The high Absorb voltage to get that last 20% SOC efficiently bubbles
through a lot of distilled water. My schedule is 1-2 gallons every 40 days,
and the company sends a reminder email at that interval.
~ The bubbling gets the tops dirty fast. A cleaning every 40 days is about
right.
~ High cost
~ Twiddling with string voltages semi-annually. This would not be an issue
if most charging is from PV.

My thoughts:
My overall impression of being married to NiFes way off the grid has so far
been favorable.In a grid standby situation, I think string voltage
twiddling would be a non-issue, who cares about the last 20% of SOC charge
efficiency in that situation? Off the grid with daily cycling, generator
use, etc, I would not consider these to be batteries for off-grid
beginners. But anyone who has been off grid for a few years with lead acid
batteries will immediately appreciate the advantages and only occasionally
curse the quirks of Nife.
Plans here: Increase my PV by about 30%. Cheap and easy, no more taking
cells in and out of the string, and less winter generator run time. Get 'em
to 80% on genny during tough snowbound times and let PV do the rest. Figure
out some Arduino solution for monitoring when Peukert's exponent changes
depending on SOC. Complain to inverter/charger manufacturers to make them
work better with NiFe.

Best regards;

Dan Fink
Adjunct Professor, Ecotech Institute
IREC Certified Instructor? for:
~ PV Installation Professional
~ Small Wind Installer
Executive Director, Buckville Energy
NABCEP Accredited Continuing Education Providers?
970.672.4342







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Re: [RE-wrenches] fusing requirement for 4 strings run to a Inverter with 2 MPPT's

[don]

While Brian T.  is correct that fusing is not required for string-to-string overcurrent protection with two strings into two channels, there is another reason to require fusing. Transformerless inverters like Fronius Primo have no transformer to provide AC-DC isolation, so a ground fault can allow excessive AC current from AC neutral to enter the DC side and fry inverter components. Transformerless inverters need fuses on both DC 
positive and DC negative legs to protect the inverter in case of ground 
fault. This is why both DC+ and DC- are switched and PV wire is 
required for DC connections-- to protect 
the inverters, not just the PV modules.  This is  also why SMA, for example, no longer has any fuses in their disconnect switches but requires a separate fused DC combiner box with fuses for both positive and negative circuits. I have had inverter damage with another inverter brand that only had fuses for the DC+. They now provide fuses on both legs. Don BarchEnergy Solar
Date: Wed, 27 Jan 2016 17:31:22 -0800
From: Brian Teitelbaum <bteitelb...@aeesolar.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] fusing requirement for 4 strings run to a
	Inverter with 2 MPPT's
Message-ID: <7b344022a97655195ced29e564a31...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Al,



As long as you only have a max of two strings going into each of the
separate MPPT channels, no string fusing is needed. So with four strings,
two on each MPPT input channel in the inverter, no string fusing is needed.
This is one of the big advantages to having multiple MPPT channels in GT
inverters.



No need to run separate conduits either. All four PV string circuits can be
run in a single conduit, as long as the conduit is properly sized for wire
fill, of course.





Brian Teitelbaum

AEE Solar





*From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
Behalf Of *Allen Frishman
*Sent:* Wednesday, January 27, 2016 6:12 AM
*To:* re-wrenches@lists.re-wrenches.org
*Subject:* [RE-wrenches] fusing requirement for 4 strings run to a Inverter
with 2 MPPT's



Wrenchers,

What is the requirement for fusing 2 strings per MPPT? Specifically for
an inverter like the Fronius Primo that has no integrated fuses.If you
run 2 strings to each MPPT do you need to fuse each string?In this case
there is a total of 4 strings which would need to be fused if using a
single mppt.



If the home runs are run in separate conduits from the array to limit the
strings in the conduit to 2 per you still have all 4 strings together in
the inverter.



All thoughts and feedback are appreciated.

*Al Frishman*
AeonSolar

*(917) 699-6641 <%28917%29%20699-6641> - cell*
*(888) 460-2867 <%2%29%20460-2867>*
*www.aeonsolar.com www.aeonsolar.com/>*
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Re: [RE-wrenches] PV step-up transformer design

[don]

Kelly- You've got phase-balancing issues that will not be entirely solved with 3-phase breakers, but that's a good place to start. As Jarmo wrote, some inverters will talk to each other to shut them all down  when one stops. Many manufacturers are now building 3-phase inverters to solve this phase-balancing issue. So your proposed solution with 3-phase breakers on both the PV and grid side is a necessary but not sufficient upgrade. Your real problem is overloaded neutral, as indicated by the melted insulation. If you put an OCPD  on the neutral (not allowed to break neutral if it is grounded) you would discover that it is running a lot more current than it is supposed to. It's not clear to me why you chose delta connection on the PV side.  A delta-wound transformer has the neutral as a center tap on one of the windings. The neutral is not balanced on all windings. If the neutral is center-tapped between legs A and B, the voltage from either A or B to neutral is the same, but from C to neutral is much higher. Each of A or B sees neutral as a half-winding away, while C is a winding-and-a-half away from neutral. It is called the High Leg or Stinger Leg. See the excellent WikiPedia listing with pictures for Delta windings. Then while an inverter across A-B is balanced on neutral, the inverters across B-C or A-C are not. Those inverters will have a lot of neutral current, leading to overloaded neutral as you are seeing. So you've got to get rid of that Delta wound transformer. Replacing it with a step-down transformer in reverse is not a fix, because that still has a delta winding. You could replace it with a 208-480 step-up with both sides in Wye configuration. Maybe you can find a straight 2-to-1 240-480 3-phase transformer with both sides in Wye; I'm not sure if these are made in 3-phase.  This would allow all the inverters to see the same neutral. Check the inverter spec sheet-- They can work with 208 Vac as well as 240 Vac although with a bit more AC current to get their power rating. The spec sheet will also show that many inverters (such as Sunny Boys) can also connect 277-to-neutral direct to the 480 grid without a big 3-phase step-up transformer at all. You did not specify which inverters you are using, but with your system configuration using several 3.8kW inverters this would seem like the best re-configuration. And it has the added advantage of not having the transformer parasitic load on the grid side all night.  Be sure to use 3-phase breakers as well. If you send me your system schematic back-channel I'd be happy to suggest a least expensive reconfiguration. Don BarchEnergy Solar
Message: 2
Date: Thu, 2 Apr 2015 15:19:11 -0700
From: "Kelly Keilwitz, Whidbey Sun & Wind" <ke...@whidbeysunwind.com>
To: RE Wrenches listserve <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] PV step-up transformer design
Message-ID: <7010da9f-54ad-477e-b855-6dec65cf8...@whidbeysunwind.com>
Content-Type: text/plain; charset="utf-8"

Wrenches,
We have issues with a 1-1/2 year old 25 kW grid-tied PV system utilizing 2 step up transformers from the array to grid. Actually it?s two identical, 12.5 kW systems (for incentive and financing reasons) on each transformer. Note that the inverter size and voltage selection was also dictated by incentives. Each of the two systems are designed as follows:

- 3, 3.8 kW, 240 Vac inverters (16A max output current) across each phase of the 240V, 3-ph Delta primary of a 15 kVA transformer. Each inverter 1-ph output has a fused disconnect. The output of all three inverters is combined into 3 phase delta configuration with terminal blocks before the transformer. Other than the inverter AC disconnects there is no OCPD on the 3-ph primary side of the transformer.

- Transformer secondary to grid is 277/480 wye. The secondary output has two fused disconnects (one at each end of the 600-ft run between array and line-side connection) each with 20-A fuses.

After more than year of operation we noticed one inverter, in one of the two identical systems, was down (monitoring showed it happened past December), indicating a grid problem. One fuse (of the 3) in the secondary (grid-side) fused disco had blown. Replaced that fuse, but then 2 fuses at the disconnect near the meter, 600 feet away, popped. 

Systematic checking of the system reveals no shorted conductors, but a problem at the transformer. Close inspection revealed that the insulation on our 90?C neutral conductor had slightly melted where it touched the X-O neutral wire of the transformer (the splice looked fine). Now it gets more interesting?.

In the last week, while troubleshooting the first 12.5 kW system, its adjacent twin system had an inverter quit with a ground-fault error (these inverters commonly will display ground fault errors for other reasons). One of the 20A fuses in the secondary (grid 277/480) side had popped. And, yup, the neutral wire h

[RE-wrenches] LG Neon 300 watt modules

[don]

Hi Jerry-I just finished a 20kW installation with 81 of these LG300s with Enphase inverters. These are the best performing 60-cell modules I could find besides SunPower.They're a bit pricey, but the customer thought they're worth it. I first tried to sell him a China brand; but this has the cachet of a more quality product from a well known company.They are performing very well. I would recommend them highly.  Don BarchEnergy Solar
Message: 7
Date: Tue, 20 Jan 2015 09:13:36 -1000
From: Jerry Shafer <jerrysgarag...@gmail.com>
To: RE-wrenches <RE-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] LG Neon 300 watt modules
Message-ID:
	<CAMUFgmUaESX3mo8NG=zye1wfpxexr1eedyje-c1aret07zt...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Hello to all.
Has anyone used or knows anything about the LG modules I am looking at the
Neon 300 for a customer, its a 60 cell 300 watt module but I/we don't use
the LG product so I am looking to the list
Jerry




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[RE-wrenches] circuit breaker for SW5548

[don]

Hi all-  I'm having some difficulty finding a replacement for the little push-button circuit breaker on an old Trace SW5548 inverter. This is located on the lower left corner of the box, below the wiring access panel. The customer has had repeated tripping of this breaker from overcurrent, so it has been doing it's job. But now the button won't reset. It's a 35 amp breaker.  I have only been able to find smaller ones in the online catalogs.Anyone know of a better parts supplier?ThanksDon BarchEnergy Solar
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Re: [RE-wrenches] 480 Wye or Delta for a SolarEdge 10K

[don]

Jarmo is correct in that 480 and 277 are right for 480 WYE.The alternative is Delta which will have different  Phase-Neutral voltages, with a hi leg from one phase. But this is never (to my knowledge) done with 480, only 240. See http://en.wikipedia.org/wiki/Three-phase_electric_powerhttp://en.wikipedia.org/wiki/High-leg_deltaAll your questions are answered by the fact that neutral and ground are connected together in your service panel, as in most every grid connected main service panel in this country.Don BarchEnergy Solar

Message: 4
Date: Tue, 16 Dec 2014 11:25:35 -0500
From: jarmo.venalai...@schneider-electric.com
To: RE-wrenches 
Subject: Re: [RE-wrenches] 480 Wye or Delta for a SolarEdge 10K
	3-phase; how can I determine what this panel is?
Message-ID:
	
	
Content-Type: text/plain; charset="utf-8"

Hi:

Grounding, (they use the term earthing in the IEC/Euro world), variations 
like this are not very common in North America as we overwhelmingly use a 
TT method which means there is a dedicated ground rod at the building.

In many other parts of the world power lines are underground and so the 
systems use different grounding/earthing methods.

These methods are classed as TT, TN, TN-C, TN-C-S, and so on...

From your explanation, I think this new building uses a variation of 
TN-C-S, (T is GND, N is neutral, the C-S means single combined Neutral/GND 
wire to the building which separates at the service entrance).

You can find a lot of info on the net, but here is an explanation from the 
IEC rules regarding TN-C-S grounding/earthing.

480/277 are the right voltages for a 480WYE.

Since its been done, there must be some applicable North American codes 
somewhere.

JARMO


_ 


Jarmo Venalainen  |   Schneider Electric   |  Solar Business  |   CANADA | 
  Training & Development Specialist - Senior 
Phone: +604-422-2528  |   Fax: +604-420-1591  |   Mobile: +604-505-0291 
Email: jarmo.venalai...@schneider-electric.com  |   Site: www.SEsolar.com 
|   Address: 3700 Gilmore Way, Burnaby, BC V5G4M1 


*** Please consider the environment before printing this e-mail 

From:
"Howard \"Scot\" Arey" 
To:
, 
Date:
12/15/2014 05:50 PM
Subject:
[RE-wrenches] 480 Wye or Delta for a SolarEdge 10K 3-phase; how can I 
determine what this panel is?

My challenge is determining the correct 480V configuration so I can use a 
3-phase Solar Edge 1 for a 12KW commercial system.  The SE10K requires 
a 480V Wye configuration.
 
The main 480 panel looks straightforward.  L1, L2, L3 come from below 
grade to three separate busbars in the panel.  A 4th wire, not taped 
white, goes to what appears to be a ground bar at the lower right of the 
panel.  Green and green-taped wires come from this bar. I do not see any 
physical connections between the L1, L2, L3 bus bars and the ground bar in 
the lower right, other than the box itself as the ground bar appears to be 
bonded to the main box itself.
 
Voltage measurements depicts 480V at line to line, and 277 Volts from each 
line to the ground (neutral?).
 
The overhead service at the road depicts 4 wires into the service head. 
The three from the three each transformers at the pole are taped 
traditional 3-phase colors.  The bare wire from the pole to the service 
head is bare wire, but is taped white as it goes into the service head 
with an insulated conductor (wire).  There is no apparent ground wire at 
the pole or inside the building that I can see but the service is 
underground and under concrete until it comes up inside the facility at 
the 480 panel board.
 
My master electrician is researching to determine the type but I wanted to 
post it here for comments, too.
 
My questions:
-  Is it possible to have an ungrounded Wye where the ?4th wire? 
actually is a neutral to the lower right bus bar, and the wires leaving 
that bar are in fact ground wires?
-  The SE10K calls for a neutral wire in a Wye config.  If this 4
th wire is a neutral, and is bonded to ground, can I run a wire from this 
to the inverter neutral, then another wire from this same bar t0 other 
ground wire location in the SE10K (right beside the neutral).
-  Is the white taped wire (the bare wire from the pole, then 
insulated and taped white into the service head) a neutral or is that 
ground.
-  Can anything other than a 480 Wye give the 480/277 voltages 
indicated above?
-  If the 4th wire is a neutral (I certainly hope it is), where 
might I find the ground electrode conductor (the building is relatively 
new, less than 10 years I believe.).  FYI, the building is metal.
 
I look forward to your comments
 
Howard ?Scot? Arey
254-300-1228
scot.a...@solarcentex.com



___

Re: [RE-wrenches] SMA TL meter communication interference?

[don]

Even at night? This is hardly believable, as the inverter is supposedly shut down at night. Maybe he meant late evening, when the inverter has not shut down yet?If the utility tech claims he can see meter interference that disappears when he opens the AC disconnect, ask him to try the same test with the DC disconnect. This simulates the inverter state at night. It is not unheard of that inverters can generate radio interference. We had to replace a pair of PVPowered 5.2 kW inverters a few years back because they interfered with the customer's AM reception so he could not listen to the ball game. The company sent replacements of a newer generation with interference filters installed that solved the problem. Don BarchEnergy Solar

Message: 11
Date: Sat, 18 Oct 2014 09:34:47 -0500
From: Kristopher Schmid <sol...@legacysolar.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] SMA TL meter communication interference?
Message-ID:
	<CAJB-iS8=qniQz3LjTJ8XZYTUbABruP-gmA9XJAyr=vmpahs...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

August,

The meter is recording correctly in both directions, but they are unable to
communicate with it remotely...even at night.  According to the utility
contact, when he opens the PV AC disconnect, the communication is restored.

Kris
On Fri, Oct 17, 2014 at 6:32 PM, August Goers <aug...@luminalt.com> wrote:

> HI Kris,
>
> It sure seems unlikely that the inverter is interfering with the the
> utility meter unless the meter isn't programmed to run backwards? What kind
> of problem is the utility reporting?
>
> Best,
>
> August
>
> Luminalt
>
> *August Goers*
>
> Luminalt Energy Corporation
>
> o: 415.641.4000
>
> m: 415.559.1525
>
> www.luminalt.com
>
>
>
> On Fri, Oct 17, 2014 at 6:51 AM, Kristopher Schmid <sol...@legacysolar.com
> > wrote:
>
>> Hi All,
>>
>> I seem to remember seeing this posted a while back, but i was unable to
>> get the archive search function to work on my browser.
>>
>> I have a recent install of an SMA SB5000TL-US-240VAC where the utility is
>> claiming that the inverter is interfering with their communication with the
>> meter.  Anyone have experience with this?  Solutions?
>>
>> Thanks!
>>
>> --
>> Shine On!
>>
>> Kris Schmid
>> Legacy Solar, LLC
>> 864 Clam Falls Trail
>> Frederic, WI 54837
>> www.legacysolar.com
>> 715-653-4295
>> NABCEP Certified PV Installer
>> Licensed Wisconsin Master Electrician
>> BSEE
>>
>> _

-- 
Shine On!

Kris Schmid
Legacy Solar, LLC
864 Clam Falls Trail
Frederic, WI 54837
www.legacysolar.com
715-653-4295
NABCEP Certified PV Installer
Licensed Wisconsin Master Electrician
BSEE
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[RE-wrenches] PV panel backing

[don]

Hi Ron- While I agree with Dan of Exeltech that it would be best to just replace the damaged panel, if you want to try salvage you might want to use a conformal coating that is commonly used to seal PC boards.  Conformal coatings can be sprayed or brushed on. In your case a brushing may further damage the fragile surfaces so you should stick with a spray on type. There are several brands that come up on a Google search. Read the Wiki page to pick the right chemistry.  http://en.wikipedia.org/wiki/Conformal_coatingDon BarchEnergy Solar> On Sun, Aug 31, 2014 at 5:32 AM, Ron Young 
> wrote:
>
>> Hello Wrenches,
>> I have an installation of 165w PV on a pole mount that was exposed to a
>> fire from the rear when the customers shop burned. 6 of the 10 panels
>> survived with only replacement of the MC4 plugs required but one of the
>> panels that is still functioning had the rear coating melted off. The cells
>> and electrical grid still function. Can anyone recommend a replacement
>> coating that may salvage this panel for a few more years. I know if left
>> exposed it will soon deteriorate but am wondering if some kind of commonly
>> available non conductive rubberized or latex type of coating might do the
>> job?
>>
>> Ron Young
>> ___
>>
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[RE-wrenches] inverter monitoring

[don]

Looking for an online monitoring solution for a pair of PowerOne (now ABB) 27.6 kW inverters. There is no need for revenue grade, so inverter monitoring will be fine. There is RS485 on board. The manufacturer ABB's website shows several options: Their VSN300 is not shipping and seems to be vaporware; and they do not sell their VSN700 to customers, they want me to go through a distributor, but the ones I know about do not know about or carry this product. So I'm looking for a reasonably priced online monitoring system that will work with these 3-phase inverters. A third-party system will probably not be able to communicate directly with the inverters, and will require current transducers. This is OK; there is a 100 amp combiner panel with a 40 amp breaker for each inverter. WiFi would save the need to run a long wire onsite, as there is a WiFi LAN onsite. Any pointers to such a data logger would be appreciated. ThanksDon BarchEnergy Solar
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Re: [RE-wrenches] Three Inverters, One Disconnect?

[don]

Hi Garrison- The dedicated breaker referred to in 705.12(D)(1) means they do not want the inverters plugged into branch breakers. One (and only one) inverter into each pole of a 3-pole breaker seems safer and better than 3 individual breakers, and seems to fit the definition of "dedicated" breaker.I don't know that you can even find single-pole 277 Vac breakersDonB


 Original Message 

Message: 6
Date: Fri, 4 Apr 2014 08:01:00 -0500
From: "Garrison Riegel" <garri...@solarserviceinc.com>
To: <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Three Inverters, One Disconnect?
Message-ID: <828201cf5005$edd065b0$c9713110$@solarserviceinc.com>
Content-Type: text/plain; charset="utf-8"

Hi Don,

Thank you for your reply.  Good idea on the single 480V inverter, but multiple subarrays at different tilts/orientations and strings lengths make that impractical unfortunately.  

It also seems like a good idea to use a single 3-pole breaker to prevent phase imbalance, but I thought each inverter required a dedicated breaker as per 705.12(D)(1).  Thoughts?

Thanks,

Garrison

From: d...@energysolarnow.com [mailto:d...@energysolarnow.com] 
Sent: Thursday, April 03, 2014 1:55 PM
To: re-wrenches@lists.re-wrenches.org; Garrison Riegel
Subject: RE: [RE-wrenches] Three Inverters, One Disconnect?

With single phase 240 each inverter output is two poles; but since you are using 277 each inverter output is between one pole and neutral, so you could indeed use a 3-pole disconnect since the neutrals are not switched.

A 3-pole breaker is usually used with 3-phase systems, but since there are 3 separate inverters it is legal to use 3 single pole breakers provided you get them into separate phase poles. However, there would be a phase imbalance if one breaker tripped and the others were still sourcing current, so it's better to use a 3-pole breaker here. 

But rather than go to all the work of wiring 3 separate 3.6 kW inverters, why not just use the PowerOne 10.0 or 12.0 kW 3-phase inverters? This would be less expensive and would need just one conduit run for input and output.

Don Barch

Energy Solar

 

 Original Message 
--

Message: 1
Date: Wed, 2 Apr 2014 17:20:36 -0500
From: "Garrison Riegel" <garri...@solarserviceinc.com ><mailto:garri...@solarserviceinc.com> >
To: "'RE-wrenches'" <re-wrenches@lists.re-wrenches.org ><mailto:re-wrenches@lists.re-wrenches.org> >
Subject: [RE-wrenches] Three Inverters, One Disconnect?
Message-ID: <817a01cf4ec1$c5d8ad00$518a0700$@solarserviceinc.com >solarserviceinc.com> >
Content-Type: text/plain; charset="us-ascii"

Hello Wrenches,

On an upcoming project we are interconnecting (3) Power-One, ahem, ABB PVI
3.6 inverters to a 3Ph 277/480V service. Each inverter output is 16A at
277V, 1Ph. Is it code compliant to run the single phase output of each
inverter to a single pole of a 3-pole [utility required] AC disconnect
before landing at each 1-pole 20A breaker in the main panel? It would be
great to avoid an inverter subpanel and 3-pole breaker in the MDP if
possible.

Thanks for your thoughts.

Garrison

Garrison Riegel

Project Manager | solarserviceinc.com >solarserviceinc.com> /> Solar Service Inc

[p] 847-677-0950 | <mailto:garri...@solarserviceinc.com>
garri...@solarserviceinc.com <mailto:garri...@solarserviceinc.com> 

NABCEP Certified PV Installation ProfessionalT







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Re: [RE-wrenches] Three Inverters, One Disconnect?

[don]

With single phase 240 each inverter output is two poles; but since you are using 277 each inverter output is between one pole and neutral, so you could indeed use a 3-pole disconnect since the neutrals are not switched.A 3-pole breaker is usually used with 3-phase systems, but since there are 3 separate inverters it is legal to use 3 single pole breakers provided you get them into separate phase poles. However, there would be a phase imbalance if one breaker tripped and the others were still sourcing current, so it's better to use a 3-pole breaker here. But rather than go to all the work of wiring 3 separate 3.6 kW inverters, why not just use the PowerOne 10.0 or 12.0 kW 3-phase inverters? This would be less expensive and would need just one conduit run for input and output.Don BarchEnergy Solar


 Original Message 
--

Message: 1
Date: Wed, 2 Apr 2014 17:20:36 -0500
From: "Garrison Riegel" 
To: "'RE-wrenches'" 
Subject: [RE-wrenches] Three Inverters, One Disconnect?
Message-ID: <817a01cf4ec1$c5d8ad00$518a0700$@solarserviceinc.com>
Content-Type: text/plain; charset="us-ascii"

Hello Wrenches,

 

On an upcoming project we are interconnecting (3) Power-One, ahem, ABB PVI
3.6 inverters to a 3Ph 277/480V service.  Each inverter output is 16A at
277V, 1Ph.  Is it code compliant to run the single phase output of each
inverter to a single pole of a 3-pole [utility required] AC disconnect
before landing at each 1-pole 20A breaker in the main panel?  It would be
great to avoid an inverter subpanel and 3-pole breaker in the MDP if
possible.

 

Thanks for your thoughts.

 

Garrison

 

Garrison Riegel

Project Manager |  solarserviceinc.com/> Solar Service Inc

[p] 847-677-0950 |  
garri...@solarserviceinc.com

 

NABCEP Certified PV Installation ProfessionalT

 




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Re: [RE-wrenches] Busbar rating with multiple main breakers

[don]

Eric-Sounds like you have a ranch panel. One 200 amp breaker will go to 200 amp busbars; the other does not have busbars at all but lugs for another subpanel. Generally these panels are sold with a  main breaker that match the busbar rating. The 120% rating is on the busbars, not the breakers per se.  The busbars allow .12 x 200 = 240 amps total as the sum of grid current coming in through the main breaker plus solar backfed current.One way to get more solar is to downsize the 200 amp main breaker to maybe 150 amps. Now you have an extra 50 amps allowance on top of the 40 amps allowed by the 120% rule, for a total of 90 amps solar current. We just did something like this with a new 600 amp subpanel. With a 600 amp main breaker it would allow .12 x 600 = 720 amps total, so only 720-600=120 amps solar allowed. But with a 400 amp main breaker then 720-400=320 amps is allowed for solar current to accommodate this 55 kW system at 208 VAC. 


 Original Message 

From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Chris Mason
Sent: Thursday, December 19, 2013 2:41 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Busbar rating with multiple main breakers

 

The 120% rule refers to source breakers, not load breakers. 

 

On Thu, Dec 19, 2013 at 3:16 PM, SunHarvest  wrote:

Hi guys -

 

Concerning the 120% rule: I've encountered several circumstances recently
where a 400A nameplate-rated (listed on inside label) main panel has two
200A main breakers. One of the breakers will be feeding the busbar in the
main and the other will feed a subpanel. I had previously thought the main
busbar is rated at the nameplate rating (400A in this case) regardless of
quantity of main breakers. My lead electrician says the main busbar in these
types of panels is derated to 200A because of the split. However, I have two
other reliable electrician friends who disagree with my lead electrician.
One of my C10 buddies says it depends on whether or not the busbar in the
main is broken up into 2 sections (200A) or it is continuous (400A). Can
anyone clear up, beyond doubt, our disagreement?

 

Thanks!

 

Eric Stikes
SunHarvest





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[RE-wrenches] 3-phase xformer efficiencies

[don]

Kirk-  The spec sheet for the 75 kva Acme transformer I just bought shows 98% efficiency. I'm planning to use this to connect 480 volt solar inverters to a 208 VAC main panel.Then a line side tap to bypass the existing 600 amp busbars in the 208 VAC panel since they won't be sufficient for the solar current backfeed with the 120% rule. Is this what you have in mind also?Don BarchEnergy Solar


 Original Message 

Message: 3
Date: Mon, 9 Dec 2013 11:57:57 -0500
From: "Kirk Herander" <k...@vtsolar.com>
To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] 3-phase xformer efficiencies
Message-ID: <006f01cef4ff$cffd39c0$6ff7ad40$@vtsolar.com>
Content-Type: text/plain; charset="us-ascii"

Hello folks,

Generally speaking, what is the efficiency range of a 480 to 208 3-phase
delta xformer, common in industrial settings, rated from 35 to 75kva?
Thanks.

Kirk Herander

VT Solar, LLC

dba Vermont Solar Engineering

NABCEPTM Certified Inaugural Certificant

NYSERDA-eligible Installer

VT RE Incentive Program Partner

802.863.1202

 




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[RE-wrenches] House fire news

[don]

Wow was that news story hard to watch with all the fear mongering. They generalized one brand to all solar panels when they asked the big question about safety. Similarly for Marco's question--- we cannot generalize all BIPV systems and judge from problems with one brand. That said, I agree with William M. that we want to do the best work possible to avoid and taint on the industry. That means fix or remove the problems...
Date: Mon, 11 Nov 2013 08:36:13 -1000
From: "Marco Mangelsdorf" 
To: "'RE-wrenches'" 
Subject: [RE-wrenches] House fire news
Message-ID: <006c01cedf0c$e7a70f50$b6f52df0$@com>
Content-Type: text/plain; charset="us-ascii"

Brings up an obvious question: are BIPV systems more of a fire risk than
standard modules mounted on top of the roof systems.

 

Opinions?

 

marco

 

Date: Mon, 11 Nov 2013 10:09:08 -0800
From: "William Miller" 
To: "RE-wrenches" 
Subject: [RE-wrenches] House fire news
Message-ID: <035801cedf09$21d24090$6576c1b0$@millersolar.com>
Content-Type: text/plain; charset="us-ascii"

Friends:

 

This was brought to my attention:
http://on.aol.com/video/are-solar-panels-a-fire-hazard--518000682?hp=1

&playlist=127173&icid=maing-grid7%7Cmain5%7Cdl12%7Csec1_lnk3%26pLid%3D403848

 
I know this is an isolated scenario, but bad PR can spread like umm,
wildfire.  We should all be aware of bad press so we can respond to
questions about safety hazards.


I think this story is relevant in that as the number of PV installations
continues to grow, the chance of an accident naturally increases. I believe
we all need to do the best work possible to minimize this risk.  Even though
some of the Code requirements seem illogical, I favor strict adherence to
the code, including the more subjective judgments on good workmanship. 

 

I look forward to the day when plastic wire ties of any type are not
accepted for wire management - I think they are sub-standard practice and
increase the likelihood of fire or shock hazards.


William Miller


cid:679355323@23072013-1054

17395 Oak Rd. Atascadero, CA 93422

www.millersolar.com millersolar.com/> 

805-438-5600 voice

 




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Re: [RE-wrenches] Fronius Installer Support Sucks- but who else?

[don]

Chris Mason wrote:>SMA just came out with their Sunny Tripower line for the US. Yes those are interesting. But they are only for 480 Wye, not 240 Delta.Is the Fronius 11.4-3 the only 3-phase inverter that can work with 240 3-phase with a hi-leg (stinger)?
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Re: [RE-wrenches] Fronius Installer Support Sucks- but who else?

[don]

Jeff- Sorry to hear about your frustration with Fronius. And thanks Bob-O for posting their tech support number. Recently I had to get this number from AEE since it is not listed in the Fronius manuals. A new installation with a pair of 11.4-3 phase Delta inverters refused to come up and detect the grid. A call to Barry at tech support solved the problem-- press the Menu button 5 times and enter a secret code number. This was of course undocumented in their manual. No reason for this kind of opaque secrecy. But is there any other option for 240 VAC 3-phase Delta inverters?   (Except for Sunny Tower with single phase inverters.)  I'm about to buy some more for another new installation with the same serviceThanksDon BarchEnergy Solar
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Re: [RE-wrenches] transformerless inverters and conductor colors

[don]

Marco- You should not transition to THHN wire at all for the DC run. The PV wire is double insulated for a good reason- the transformerless inverters are such suckers for a ground fault that they need the extra protection. That's why the NEC specifies PV wire.  I recently did an installation like you wrote, with a transition at the j-box. This developed an intermittent ground fault when wet, and when the P1 inverter failed it was deemed out of warranty.  Learn from my mistake-- use PV wire all the way to the inverter. That said, does anyone know where to get 1000 volt PV wire in colors other than red, black, and white?It would be nice to color code the positive runs like is possible with colors of THHN.I'm thinking of buying spools of white and spraying plastic paint on them for a striped color coding.Don BarchEnergy Solar
Message: 3
Date: Mon, 23 Sep 2013 09:27:30 -1000
From: "Marco Mangelsdorf" 
To: "'RE-wrenches'" 
Subject: [RE-wrenches] transformerless inverters and conductor colors
Message-ID: <01ceb892$f3e41470$dbac3d50$@com>
Content-Type: text/plain; charset="us-ascii"

Hi all,

We're doing more and more installs with TL inverters (SMA and P1).

I'm using double-insulated wire from the array string to the first
enclosure, as in j-box, and then transitioning to standard THHN/THWN wire.

 



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Re: [RE-wrenches] RE-wrenches Digest, Vol 6, Issue 221

[don]

Robin's description of the problem matches that given by the Tigo and PowerOne techs when we recently had the same issue. In fact, PowerOne now has a pdf on their website to the effect that you must disable the inverter's MPPT scan when using Tigos with them. But they will not admit to any product shortcomings. Each accused the other's tracking algorithm of being "too aggressive," leading me to suspect they don't really quite know what is going on. The crux is the Tigo Maximizers have the solar modules in series strings, with multiple strings in parallel. They do their own MPPT tracking at the module level, and attempt to adjust module and string voltages to match each other in the presence of shading. This can drive inverters nuts, as they are trying to do this also. It does not bode well for the new "smart" solar modules with Tigo Maximizers built in. They have to learn to play nice.Tigos drive themselves nuts if, for example, two out of three series strings have Tigos but the third string does not. They worked OK for the two strings with mixed modules, but their algorithm could not figure out why it was unable to control net string voltage, and shut down some modules until it arrived at some reduced power level it can control. This caused me to remove them from the array. Solar Edge is different-- their module units are DC-DC converters that boost module voltage to a fixed 375 VDC. All modules can be in parallel (up to amperage limitations) like with microinverters-- no series strings. This is potentially more compatible with other inverters, hence their announcement to that effect. Don BarchEnergy Solar
From: Ryan <r...@kb1uas.com>
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [RE-wrenches] Tigo and SMA AFCI - 

 From Robin

It has been pointed out that the Tigo modules can and do blow up some 
charge controllers and inverters. When a charge controller or inverter 
has fairly fast tracking, the two units fight each other. We have found 
Classics using the fast tracking mode will blow up with Tigo's in the 
system. We also found that putting the Classic in the slower tracking 
mode, Legacy, solves the issue. We are aware that at least one major 
inverter model must defeat the tracking in order not to blow up. We have 
not yet tested our arc fault detectors with Tigo modules, but plan on 
doing this in the near future. It might be possible that the Tigo 
modules present a signature that looks like an arc. That must be what is 
happening with the SMA inverter.

Robin


On 6/5/2013 3:33 PM, SunHarvest wrote:
> Just an FYI for anyone wanting to use Tigo optimizers with SMA 
> inverters incorporating AFCI -
> According to SMA the Tigo optimizers will not operate with the SMA 
> inverters. They didn't go into detail. They just said the AFCI feature 
> of the Sunny Boy is not compatible with Tigo. After further discussion 
> they acknowledged that disabling the AFCI feature in the Sunny Boy 
> would allow compatibility with the Tigo optimizer. Awesome.
> After talking this over with Tigo they came to the same conclusion but 
> neither company seemed too happy or confident in the marriage. Awesome.
> Eric Stikes
> SunHarvest


From: Richard L Ratico
Sent: Wednesday, June 5, 2013 6:44 PM
To: re-wrenches@lists.re-wrenches.org
Reply To: RE-wrenches
Subject: Re: [RE-wrenches] SolarEdge Optimizer - Was: Tigo and SMA AFCI - Was: AC coupled, grid-tied Sunny Island - contactor & bypass


SolarEdge makes an optimizer / inverter system. We just installed one. Our
clients are happy. So are we.

Don't know if you can AC couple the inverter. Their website says they are about
to release a version of the optimizer that will work with other manufacturer's
inverters.

Dick Ratico
Solarwind Electric




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Re: [RE-wrenches] Solar Presentations for Kids

[don]

Kids love things that move. Get an electric motor powered by a solar panel and make something move.Recently at a science fair there was some difficulty with the distinction between power and voltage, especially Voc and Vmp. But when the solar panel and voltmeter were attached to a model car chassis so it would show voltage as the solar panel was lit  and made the car move, the light bulbs in their heads lit up. Another visual demonstration is the solar powered fan pointing straight up that balances a beach ball on the column of air. Shade the solar panel and watch the beach ball fallDon Barchenergy Solar
From: Jason Szumlanski <ja...@fafcosolar.com>

I'm looking for an idea, project, or pre-made kit to engage a group of 6-10
year old kids for an hour. I've been doing PowerPoint presentations and
games in the past for these types of events, but I'm finding it a bit
stale. Any ideas to create a little more excitement and wonder?




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Re: [RE-wrenches] used panel mount questions

[don]

I would not trust adhesive on the backs of panels for decades. This would be especially a concern with tiltups or ground mounts where there is more wind loading. When mounting some frameless BP modules I made some 4-inch long edge moldings of slotted hard foam called SeaFoam that is sold (but not manufactured) by Tap Plastics. Then they were compatible with standard bolt-down edge-  and mid-clamps.Don BarchEnergy SolarOn 5/30/2013 4:14 PM, Todd Cory wrote:
wrenches,

 i have a customer who purchased 20 used astropower ap75   
modules. they are frameless and appear to have been previously  
 mounted using four, 2" wide X 10" long strips of blue rigid   
foam, glued to the back of each module with some kind of   
adhesive.

 two questions:

 this seems to be a reasonable mounting system id like to   
repeat. would anyone familiar with this kind of mounting   
technique be willing to comment/speculate on an adhesive that   
would not degrade the tedlar backsheet? whatever was   
previously used worked great.

 what kind of flat/smooth mounting surface would folks suggest  
 the other side of the blue foam be attached to? the only thing 
  i can think of is plywood, but that would rot over time.

 thanks,

 todd
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Re: [RE-wrenches] not sure what's going on here

[don]

Ron et al-The firmware in the controller sounds likely, but a faulty shorted bypass diode does not. Isn't that what bypass diodes are supposed to do-- turn on and short (bypass) a shaded row of cells?We use to see this half-panel voltage as a failure mode with the old Kyocera 120's when they were still blue. The solder mask fails in a hot spot and opens, so no current can flow in that row of cells. Then the bypass diode is just doing it's job by bypassing current at lower module voltage, just as it does when half the module is shaded. If there are other modules in parallel they will push current into the reduced-voltage one until they are also at reduced voltage, which is sensed by the controller. Sounds like a lot of current is being pushed through the damaged module, which will fry the hard-working bypass diode(s) or the solder mask wire in that low module.  Best to disconnect the low module or the others will kill it. I cannot think of any physical way the rest of the solar modules can work at full voltage for awhile without the damaged one, then have the voltage drop suddenly under load, only to be seen at full voltage again when disconnected. Do I have this sequence right?-- This sounds like software (or firmware) attempting to do MPPT in the controller.  If it is faulty firmware as Larry C. wrote then it should be upgraded. So, could the controller be complicit in damaging the low module? HmmmDon BarchEnergy Solar
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[RE-wrenches] Dual Channel Inverters

[don]

Hi all- While I have not had the failure problems noted with microinverters, PowerOne inverters have recently given me a big headache. Installed their 6kW model last November that failed in a month. They replaced it under warranty, no problem no reimbursement. Then the replacement failed in March. Again replaced, no problem. But that's the problem-- there was no indication from the inverter of why it failed. When the replacement inverter that was installed in March failed in April, they declared it out of warranty and made me pay nearly $900 for repairs. This is less than 6 months from initial installation. All the failures occurred after rainy weather. This time I bought megaohm meter and checked the wiring. There was a nick in the insulation where a negative DC home run pulled around a rail corner, with a small but noticable burn spot. This did not show up with a standard meter check, but it did with the megger and some watering from a hose. OK, so there is an intermittent ground fault. With a transformer inverter that would just be a blown fuse with a ground fault error message. But it seems this inverter will self destruct with a ground fault. No error message or any other indication that even PowerOne would or could relate before sending 3 replacements. The Tigo monitors indicated that each inverter failure happened at 
morning power-up, with minimal solar current. Oh, and having Tigo 
monitors in the system but not on the one-line drawing was PowerOne's 
nominal excuse for canceling their warranty. They posted a document on their website dated March 10,
 right after the second failure, to the effect that when using Tigo 
monitors you must disable the inverter MPPT scan so they don't fight. 
But didn't tell me, or apparently their tech staffThe post-mortem on the last two inverters (performed well after the replacements were sent) indicated over-current in the IGBTs.  So where is this lethal current coming from? There are only two strings, one each into this dual channel inverter.  There is not enough solar current to kill it even in broad daylight. But a morning power-up failure can only mean some AC input surge current sneaks through the ground fault and into the DC inputs. Sounds like a design flaw to me... There should not be anything that can kill an inverter other than over-voltage or over-current; and that would kill it quick, not a month or months later after a rain.Can anyone suggest a possible failure mechanism? Surely not the dreaded electrolytic caps-- the inverter is mounted under a dry eve.In general, how are transformerless inverters protected internally from external ground faults? And the obvious question is: how could anyone trust a company with this kind of warranty service?ThanksDon BarchEnergy Solar

Message: 13
Date: Tue, 7 May 2013 09:03:13 -0600
From: Troy Harvey 
To: RE-wrenches 
Subject: [RE-wrenches] Dual Channel Inverters
Message-ID: <1f568bac-8d04-4e09-bc44-9090c147f...@heliocentric.org>
Content-Type: text/plain; charset="windows-1252"

Since we stopped using micro-inverters due to the high failure rate, network problems, difficultly in replacement ? I've been using the power-one inverters a bunch because the dual channels solve most of tricky issues like different roof aspects, shading, and uneven strings.

However, they are limited to 6kW, which is only mid sized in todays world. I'm constantly having to design 7-12k systems in residential applications all the time. Any other dual channel inverts of the market for 240VAC? I remember back a few years ago that sharp had a 3-channel inverter. Doesn't look like it is still around.

thanks,

Troy Harvey
-
Principal Engineer
Heliocentric
801-453-9434
tahar...@heliocentric.org





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