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 Barch
Energy Solar
-------- Original Message --------
Subject: RE-wrenches Digest, Vol 13, Issue 59
From: [email protected]
Date: Sun, March 01, 2020 2:19 pm
To: [email protected]
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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 <[email protected]>
To: RE-wrenches <[email protected]>
Subject: [RE-wrenches] OK, so what iwould happen if I do this...
Message-ID: <[email protected]>
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 <[email protected]>
To: [email protected]
Subject: Re: [RE-wrenches] OK, so what iwould happen if I do this...
Message-ID: <[email protected]>
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 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
>
> _______________________________________________
> List sponsored by Redwood Alliance
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Message: 3
Date: Sun, 1 Mar 2020 08:58:45 -0800
From: Kent Osterberg <[email protected]>
To: [email protected]
Subject: Re: [RE-wrenches] OK, so what iwould happen if I do this...
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8; format=flowed
Mark,
I believe that your plan would fail because you are forcing power to
flow through the XP inverter backwards to charge the batteries. I don't
believe the XP inverter can do that. The grid tied inverter would
probably connect then immediately shut down, or connect and immediately
ruin the XP inverter. It would work if you had a inverter with a
bidirectional architecture like a Magnum, Outback, or Schneider
inverter. But even then you'd have a hazardous situation because the
cooling water is going to evaporate.
Kent Osterberg
Blue Mountain Solar
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 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
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> List Address: [email protected]
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://www.mail-archive.com/[email protected]/maillist.html
>
> List rules & etiquette:
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>
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> www.members.re-wrenches.org
>
>
------------------------------
Message: 4
Date: Sun, 1 Mar 2020 07:31:36 -1000
From: Jerry Shafer <[email protected]>
To: RE-wrenches <[email protected]>
Subject: Re: [RE-wrenches] OK, so what iwould happen if I do this...
Message-ID:
<camufgmvybnmmzge__tjds9xpfsou59jdf3wwskfhjw291vg...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Mark
What you are saying is to AC couple but most likely this would fail as your
battery fills not enough loads HBCO or to much loads and your battery does
a LBCO, either way you would be better off spending the money in a maybe a
Outback Skybox easy install and is high voltage PV input and even a small
48 volt bank but think about storage
Jerry
On Sat, Feb 29, 2020 at 1:27 PM Mark Frye <[email protected]> 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 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
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> List Address: [email protected]
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://www.mail-archive.com/[email protected]/maillist.html
>
> List rules & etiquette:
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>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>
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