Re: [RE-wrenches] Step-up/Step-down Transformer question

[Jay]

Thx Brian. 

I guess I was thinking that 50kw + was probably 
A darn big house and probably be outbuildings 
that the inverters would be installed on. 

Yea bringing 1000vdc to a house is a bit much but then
we said that with 600v too. 

Jay
Peltz power

> On Sep 18, 2018, at 6:34 PM, Brian Mehalic  wrote:
> 
> Currently up in the air as to whether 2020 will allow that on 1- and 2- 
> family houses. If so then yes...currently don’t know of any. 
> 
> Brian
> 
>> On Sep 18, 2018, at 2:45 PM, Jay  wrote:
>> 
>> Does anyone make a 1000vdc single phase inverter?
>> Would reduce wire costs dramatically 
>> 
>> Jay
>> Peltz power. 
>> 
>>> On Sep 18, 2018, at 11:36 AM, Lorenzo Ortiz  wrote:
>>> 
>>> Thanks for all the input guys.  After looking at the 3 phase with 
>>> transformer options with some transformer manufacturers, that has been 
>>> pretty much ruled out due to complexity/cost. 
>>> With single phase step-up and step-down transformers, even at 600VAC, it 
>>> still requires some monster wire.
>>> The best solution seems to be placing the inverters next to the POI and 
>>> just running long strings from the array back to the inverters and 
>>> accepting up to 4%-5% voltage drop. And that's with #8 instead of the usual 
>>> #10 AND accounting for worst-case production.
>>> 
>>> Man, sometimes this solar stuff is just crazy...
>>> 
 On Tue, Sep 18, 2018 at 10:15 AM, Blake Gleason 
  wrote:
 Good advice already on this thread.  A couple of points to consider:
 
 1. Re: step-up/step-down option (probably what I'd do): definitely pay 
 attention to transformer spec to minimize both magnetization and operating 
 losses.  Newer DOE 2016-compliant transformers are MUCH better than 
 before, and that's just the minimum standard.  If you really want to 
 minimize magnetization losses, you can always design a relay/timer to 
 disconnect the transformers at night (from the interconnection side), 
 although I've found that this setup is either very expensive or too 
 unreliable (nuisance tripping upon re-connect, timer gets "off" cycle 
 somehow, etc).
 
 2. I think someone mentioned a 480V single-phase inverter.  I'm not aware 
 of a high-quality product meeting that description.  Is there one?  All of 
 the "480V" single-phase inverters I'm aware of are 277V (line to neutral), 
 which is hardly worth the transformer effort (versus 240V).
 
 3. Definitely use aluminum wire for the long run.  If wire size is still 
 too large, even with step up/down tranformers, consider allowing slightly 
 increased voltage drop at full power (say, 5%), and, depending on typical 
 grid voltage at the site, change taps on one of the transformers to err on 
 the low side (from inverters' point-of-view), to keep the inverters from 
 tripping at upper voltage limit at full power (max voltage drop/rise).
 
 
 Blake
 
> On Tue, Sep 18, 2018 at 9:57 AM, Jerry Shafer  
> wrote:
> Lorenzo
> You might want to look at relocating the inverter(s) closer to the meter 
> instead of the array, one reason is even if there is some line loss at 
> full power its less as the voltage goes up and the inverter does not see 
> the line resistance that can cause high voltage issues at the inverter. 
> Some engineers use more side of peak performance than full power, this 
> keeps wite size down and does not effect output
> Jerry
> 
> On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz"  wrote:
> Wrenches,
> 
> We have a PV array situated about 900' from the POI (240V 1PH). We 
> initially spec'd (5) 11.4kW inverters and the combined output would be 
> 238A. The wire size required for this current over that distance is cost 
> prohibitive.
> 
> A solution was to use a single 50kW 3 phase inverter at the array and 
> then convert it to 240V... somehow? Is anyone familiar with how to go 
> about doing this? My thought was to have a step down transformer at the 
> POI and pull off two legs to get 240V. Is this even a thing?
> 
> The other, more expensive option is to use a step up transformer at the 
> array and a step down at the POI to get us a smaller wire size.
> 
> Thanks for any input.
> 
> 
> -- 
> Loren Ortiz   Commercial PV Designer
> 
> lo...@cal-solar.com  (530) 274-3671
>   
> 
> 
> 
> Showroom located at: 149 E Main St. Grass Valley, CA 95945
> ___
> List sponsored by Redwood Alliance
> 
> List Address: RE-wrenches@lists.re-wrenches.org
> 
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
> 
> List-Archive: 
> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
> 
> List rules & etiquette:
> 

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Brian Mehalic]

Currently up in the air as to whether 2020 will allow that on 1- and 2- family 
houses. If so then yes...currently don’t know of any. 

Brian

> On Sep 18, 2018, at 2:45 PM, Jay  wrote:
> 
> Does anyone make a 1000vdc single phase inverter?
> Would reduce wire costs dramatically 
> 
> Jay
> Peltz power. 
> 
>> On Sep 18, 2018, at 11:36 AM, Lorenzo Ortiz  wrote:
>> 
>> Thanks for all the input guys.  After looking at the 3 phase with 
>> transformer options with some transformer manufacturers, that has been 
>> pretty much ruled out due to complexity/cost. 
>> With single phase step-up and step-down transformers, even at 600VAC, it 
>> still requires some monster wire.
>> The best solution seems to be placing the inverters next to the POI and just 
>> running long strings from the array back to the inverters and accepting up 
>> to 4%-5% voltage drop. And that's with #8 instead of the usual #10 AND 
>> accounting for worst-case production.
>> 
>> Man, sometimes this solar stuff is just crazy...
>> 
>>> On Tue, Sep 18, 2018 at 10:15 AM, Blake Gleason 
>>>  wrote:
>>> Good advice already on this thread.  A couple of points to consider:
>>> 
>>> 1. Re: step-up/step-down option (probably what I'd do): definitely pay 
>>> attention to transformer spec to minimize both magnetization and operating 
>>> losses.  Newer DOE 2016-compliant transformers are MUCH better than before, 
>>> and that's just the minimum standard.  If you really want to minimize 
>>> magnetization losses, you can always design a relay/timer to disconnect the 
>>> transformers at night (from the interconnection side), although I've found 
>>> that this setup is either very expensive or too unreliable (nuisance 
>>> tripping upon re-connect, timer gets "off" cycle somehow, etc).
>>> 
>>> 2. I think someone mentioned a 480V single-phase inverter.  I'm not aware 
>>> of a high-quality product meeting that description.  Is there one?  All of 
>>> the "480V" single-phase inverters I'm aware of are 277V (line to neutral), 
>>> which is hardly worth the transformer effort (versus 240V).
>>> 
>>> 3. Definitely use aluminum wire for the long run.  If wire size is still 
>>> too large, even with step up/down tranformers, consider allowing slightly 
>>> increased voltage drop at full power (say, 5%), and, depending on typical 
>>> grid voltage at the site, change taps on one of the transformers to err on 
>>> the low side (from inverters' point-of-view), to keep the inverters from 
>>> tripping at upper voltage limit at full power (max voltage drop/rise).
>>> 
>>> 
>>> Blake
>>> 
 On Tue, Sep 18, 2018 at 9:57 AM, Jerry Shafer  
 wrote:
 Lorenzo
 You might want to look at relocating the inverter(s) closer to the meter 
 instead of the array, one reason is even if there is some line loss at 
 full power its less as the voltage goes up and the inverter does not see 
 the line resistance that can cause high voltage issues at the inverter. 
 Some engineers use more side of peak performance than full power, this 
 keeps wite size down and does not effect output
 Jerry
 
 On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz"  wrote:
 Wrenches,
 
 We have a PV array situated about 900' from the POI (240V 1PH). We 
 initially spec'd (5) 11.4kW inverters and the combined output would be 
 238A. The wire size required for this current over that distance is cost 
 prohibitive.
 
 A solution was to use a single 50kW 3 phase inverter at the array and then 
 convert it to 240V... somehow? Is anyone familiar with how to go about 
 doing this? My thought was to have a step down transformer at the POI and 
 pull off two legs to get 240V. Is this even a thing?
 
 The other, more expensive option is to use a step up transformer at the 
 array and a step down at the POI to get us a smaller wire size.
 
 Thanks for any input.
 
 
 -- 
 Loren Ortiz   Commercial PV Designer
 
 lo...@cal-solar.com  (530) 274-3671
   
 
 
 
 Showroom located at: 149 E Main St. Grass Valley, CA 95945
 ___
 List sponsored by Redwood Alliance
 
 List Address: RE-wrenches@lists.re-wrenches.org
 
 Change listserver email address & settings:
 http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
 
 List-Archive: 
 http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
 
 List rules & etiquette:
 www.re-wrenches.org/etiquette.htm
 
 Check out or update participant bios:
 www.members.re-wrenches.org
 
 
 
 ___
 List sponsored by Redwood Alliance
 
 List Address: RE-wrenches@lists.re-wrenches.org
 
 Change listserver email address & settings:
 http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
 
 List-Archive: 

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Jay]

Does anyone make a 1000vdc single phase inverter?
Would reduce wire costs dramatically 

Jay
Peltz power. 

> On Sep 18, 2018, at 11:36 AM, Lorenzo Ortiz  wrote:
> 
> Thanks for all the input guys.  After looking at the 3 phase with transformer 
> options with some transformer manufacturers, that has been pretty much ruled 
> out due to complexity/cost. 
> With single phase step-up and step-down transformers, even at 600VAC, it 
> still requires some monster wire.
> The best solution seems to be placing the inverters next to the POI and just 
> running long strings from the array back to the inverters and accepting up to 
> 4%-5% voltage drop. And that's with #8 instead of the usual #10 AND 
> accounting for worst-case production.
> 
> Man, sometimes this solar stuff is just crazy...
> 
>> On Tue, Sep 18, 2018 at 10:15 AM, Blake Gleason  
>> wrote:
>> Good advice already on this thread.  A couple of points to consider:
>> 
>> 1. Re: step-up/step-down option (probably what I'd do): definitely pay 
>> attention to transformer spec to minimize both magnetization and operating 
>> losses.  Newer DOE 2016-compliant transformers are MUCH better than before, 
>> and that's just the minimum standard.  If you really want to minimize 
>> magnetization losses, you can always design a relay/timer to disconnect the 
>> transformers at night (from the interconnection side), although I've found 
>> that this setup is either very expensive or too unreliable (nuisance 
>> tripping upon re-connect, timer gets "off" cycle somehow, etc).
>> 
>> 2. I think someone mentioned a 480V single-phase inverter.  I'm not aware of 
>> a high-quality product meeting that description.  Is there one?  All of the 
>> "480V" single-phase inverters I'm aware of are 277V (line to neutral), which 
>> is hardly worth the transformer effort (versus 240V).
>> 
>> 3. Definitely use aluminum wire for the long run.  If wire size is still too 
>> large, even with step up/down tranformers, consider allowing slightly 
>> increased voltage drop at full power (say, 5%), and, depending on typical 
>> grid voltage at the site, change taps on one of the transformers to err on 
>> the low side (from inverters' point-of-view), to keep the inverters from 
>> tripping at upper voltage limit at full power (max voltage drop/rise).
>> 
>> 
>> Blake
>> 
>>> On Tue, Sep 18, 2018 at 9:57 AM, Jerry Shafer  
>>> wrote:
>>> Lorenzo
>>> You might want to look at relocating the inverter(s) closer to the meter 
>>> instead of the array, one reason is even if there is some line loss at full 
>>> power its less as the voltage goes up and the inverter does not see the 
>>> line resistance that can cause high voltage issues at the inverter. Some 
>>> engineers use more side of peak performance than full power, this keeps 
>>> wite size down and does not effect output
>>> Jerry
>>> 
>>> On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz"  wrote:
>>> Wrenches,
>>> 
>>> We have a PV array situated about 900' from the POI (240V 1PH). We 
>>> initially spec'd (5) 11.4kW inverters and the combined output would be 
>>> 238A. The wire size required for this current over that distance is cost 
>>> prohibitive.
>>> 
>>> A solution was to use a single 50kW 3 phase inverter at the array and then 
>>> convert it to 240V... somehow? Is anyone familiar with how to go about 
>>> doing this? My thought was to have a step down transformer at the POI and 
>>> pull off two legs to get 240V. Is this even a thing?
>>> 
>>> The other, more expensive option is to use a step up transformer at the 
>>> array and a step down at the POI to get us a smaller wire size.
>>> 
>>> Thanks for any input.
>>> 
>>> 
>>> -- 
>>> Loren Ortiz   Commercial PV Designer
>>> 
>>> lo...@cal-solar.com  (530) 274-3671
>>>   
>>> 
>>> 
>>> 
>>> Showroom located at: 149 E Main St. Grass Valley, CA 95945
>>> ___
>>> List sponsored by Redwood Alliance
>>> 
>>> List Address: RE-wrenches@lists.re-wrenches.org
>>> 
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>> 
>>> List-Archive: 
>>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>> 
>>> List rules & etiquette:
>>> www.re-wrenches.org/etiquette.htm
>>> 
>>> Check out or update participant bios:
>>> www.members.re-wrenches.org
>>> 
>>> 
>>> 
>>> ___
>>> List sponsored by Redwood Alliance
>>> 
>>> List Address: RE-wrenches@lists.re-wrenches.org
>>> 
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>> 
>>> List-Archive: 
>>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>> 
>>> List rules & etiquette:
>>> www.re-wrenches.org/etiquette.htm
>>> 
>>> Check out or update participant bios:
>>> www.members.re-wrenches.org
>>> 
>>> 
>> 
>> 
>> 
>> -- 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Lorenzo Ortiz]

Thanks for all the input guys.  After looking at the 3 phase with
transformer options with some transformer manufacturers, that has been
pretty much ruled out due to complexity/cost.
With single phase step-up and step-down transformers, even at 600VAC, it
still requires some monster wire.
The best solution seems to be placing the inverters next to the POI and
just running long strings from the array back to the inverters and
accepting up to 4%-5% voltage drop. And that's with #8 instead of the usual
#10 AND accounting for worst-case production.

Man, sometimes this solar stuff is just crazy...

On Tue, Sep 18, 2018 at 10:15 AM, Blake Gleason 
wrote:

> Good advice already on this thread.  A couple of points to consider:
>
> 1. Re: step-up/step-down option (probably what I'd do): definitely pay
> attention to transformer spec to minimize both magnetization and operating
> losses.  Newer DOE 2016-compliant transformers are MUCH better than before,
> and that's just the minimum standard.  If you really want to minimize
> magnetization losses, you can always design a relay/timer to disconnect the
> transformers at night (from the interconnection side), although I've found
> that this setup is either very expensive or too unreliable (nuisance
> tripping upon re-connect, timer gets "off" cycle somehow, etc).
>
> 2. I think someone mentioned a 480V single-phase inverter.  I'm not aware
> of a high-quality product meeting that description.  Is there one?  All of
> the "480V" single-phase inverters I'm aware of are 277V (line to neutral),
> which is hardly worth the transformer effort (versus 240V).
>
> 3. Definitely use aluminum wire for the long run.  If wire size is still
> too large, even with step up/down tranformers, consider allowing slightly
> increased voltage drop at full power (say, 5%), and, depending on typical
> grid voltage at the site, change taps on one of the transformers to err on
> the low side (from inverters' point-of-view), to keep the inverters from
> tripping at upper voltage limit at full power (max voltage drop/rise).
>
>
> Blake
>
> On Tue, Sep 18, 2018 at 9:57 AM, Jerry Shafer 
> wrote:
>
>> Lorenzo
>> You might want to look at relocating the inverter(s) closer to the meter
>> instead of the array, one reason is even if there is some line loss at full
>> power its less as the voltage goes up and the inverter does not see the
>> line resistance that can cause high voltage issues at the inverter. Some
>> engineers use more side of peak performance than full power, this keeps
>> wite size down and does not effect output
>> Jerry
>>
>> On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz"  wrote:
>>
>> Wrenches,
>>
>> We have a PV array situated about 900' from the POI (240V 1PH). We
>> initially spec'd (5) 11.4kW inverters and the combined output would be
>> 238A. The wire size required for this current over that distance is cost
>> prohibitive.
>>
>> A solution was to use a single 50kW 3 phase inverter at the array and
>> then convert it to 240V... somehow? Is anyone familiar with how to go about
>> doing this? My thought was to have a step down transformer at the POI and
>> pull off two legs to get 240V. Is this even a thing?
>>
>> The other, more expensive option is to use a step up transformer at the
>> array and a step down at the POI to get us a smaller wire size.
>>
>> Thanks for any input.
>>
>>
>> --
>> *Loren Ortiz   Commercial PV Designer*
>>
>> lo...@cal-solar.com *  (530) 274-3671*
>>
>>
>>
>> 
>> *Showroom located at: 149 E Main St. Grass Valley, CA 95945*
>> ___
>> List sponsored by Redwood Alliance
>>
>> List Address: RE-wrenches@lists.re-wrenches.org
>>
>> Change listserver email address & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> List-Archive: http://www.mail-archive.com/re
>> -wrenc...@lists.re-wrenches.org/maillist.html
>>
>> List rules & etiquette:
>> www.re-wrenches.org/etiquette.htm
>>
>> Check out or update participant bios:
>> www.members.re-wrenches.org
>>
>>
>>
>> ___
>> List sponsored by Redwood Alliance
>>
>> List Address: RE-wrenches@lists.re-wrenches.org
>>
>> Change listserver email address & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> List-Archive: http://www.mail-archive.com/re
>> -wrenc...@lists.re-wrenches.org/maillist.html
>>
>> List rules & etiquette:
>> www.re-wrenches.org/etiquette.htm
>>
>> Check out or update participant bios:
>> www.members.re-wrenches.org
>>
>>
>>
>
>
> --
>
>
>
>
> 
>
>
> 
> 
> 
> 
> 
> 

Re: [RE-wrenches] Low voltage DC v. higher voltage DC

[Harry Mahon]

Marco –

I will need to ask for information about the BYD availability.  Once those 
units have all required listings/certifications and are available in US, they 
should be ready to use with SBS.  The CANBUS comms to the BMS has already been 
vetted, and they are on the SMA Approved battery list already.  But I will get 
confirmation on the immediate usability.

Best regards –
Mike




SMA America
Michael Mahon
Technical Trainer, Solar Academy
6020 West Oaks Boulevard, Suite 300
Rocklin, CA 95765
U.S.A.
Mobile:   +1 916 918 9412
www.SMA-America.com

Solar Academy: 
www.SMA-America.com/partners/sma-solar-academy/overview.html

Full training schedule: 
https://www.sma-america.com/partners/sma-solar-academy/seminars/trainings/training/list.html


[http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/facebook.jpg]
 [http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/twitter.jpg] 
  
[http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/wordpress.jpg] 
  [Linkedin Logo] 
  
[http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/youtube.jpg] 
  [SMAAFORUM_ICON] 

[cid:image008.jpg@01D43B9E.70803930]


This email and any attachments thereto may contain SMA America, LLC 
confidential, privileged and private material for the sole use of the intended 
recipient. Any review, copying, or distribution of this email (or any 
attachments thereto) by others is strictly prohibited. If you are not the 
intended recipient, please contact the sender immediately and permanently 
delete the original and any copies of this email and any attachments thereto. 
Thank you.

From: RE-wrenches  On Behalf Of 
Marco Mangelsdorf
Sent: Monday, September 17, 2018 10:20 PM
To: RE-wrenches 
Subject: Re: [RE-wrenches] Low voltage DC v. higher voltage DC

Mahalo Mike.

Can you tell us please when the SS will actually be able to integrate the BYD 
battery platform in the north American market?

marco

On Monday, September 17, 2018, Harry Mahon 
mailto:michael.ma...@sma-america.com>> wrote:
Marco and all – yes that is the correct spec sheet for the BYD batteries that 
will work with Sunny Boy Storage.

SMA strongly would recommend the Sunny Island for off-grid in general and 
certainly whole home backup.  See the attached from Home Power April/May 2011; 
quad stack of SIs acting as UPS for the home – just charging batteries when 
grid is present, powering home with batteries/PV when grid is gone.  A dual 
split phase cluster is almost 24,000 W continuous (!) capability and can handle 
crazy power factor loads with no issues.  Built in generator functions and two 
relay positions per Sunny Island allow for lots of redundancy and fail-safe 
load shedding to be built in.

The Sunny Boy Storage (SBS) is designed to be a grid-tied inverter to allow 
higher self consumption of local PV power.  Even with the ABU to allow off grid 
operation (grid forming on its AC outputs rather than just on the dedicated 
120VAC Secure Power Supply outlet), there can be a several second delay in the 
switch from grid power to microgrid as the ABU must signal the Sunny Boy 
Storage that it has disconnected from the grid and that it is safe for the SBS 
to form a grid on its output terminals.  Also be aware that there is no 
master-slave configuration ability with the SBS – they will always assume they 
are acting independently on their energy meter input information.

Best regards –
Mike

SMA America
Michael Mahon
Technical Trainer, Solar Academy
6020 West Oaks Boulevard, Suite 300
Rocklin, CA 95765
U.S.A.
Mobile:   +1 916 918 9412
www.SMA-America.com

Solar Academy: 
www.SMA-America.com/partners/sma-solar-academy/overview.html

Full training schedule: 
https://www.sma-america.com/partners/sma-solar-academy/seminars/trainings/training/list.html


[http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/facebook.jpg][http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/twitter.jpg]
 [http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/wordpress.jpg] 
  [Linkedin Logo] 
  
[http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/youtube.jpg] 
  [SMAAFORUM_ICON] 

[cid:image008.jpg@01D43B9E.70803930]


This email and any attachments thereto may contain SMA America, LLC 
confidential, privileged and private material for the sole use 

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Blake Gleason]

Good advice already on this thread.  A couple of points to consider:

1. Re: step-up/step-down option (probably what I'd do): definitely pay
attention to transformer spec to minimize both magnetization and operating
losses.  Newer DOE 2016-compliant transformers are MUCH better than before,
and that's just the minimum standard.  If you really want to minimize
magnetization losses, you can always design a relay/timer to disconnect the
transformers at night (from the interconnection side), although I've found
that this setup is either very expensive or too unreliable (nuisance
tripping upon re-connect, timer gets "off" cycle somehow, etc).

2. I think someone mentioned a 480V single-phase inverter.  I'm not aware
of a high-quality product meeting that description.  Is there one?  All of
the "480V" single-phase inverters I'm aware of are 277V (line to neutral),
which is hardly worth the transformer effort (versus 240V).

3. Definitely use aluminum wire for the long run.  If wire size is still
too large, even with step up/down tranformers, consider allowing slightly
increased voltage drop at full power (say, 5%), and, depending on typical
grid voltage at the site, change taps on one of the transformers to err on
the low side (from inverters' point-of-view), to keep the inverters from
tripping at upper voltage limit at full power (max voltage drop/rise).


Blake

On Tue, Sep 18, 2018 at 9:57 AM, Jerry Shafer 
wrote:

> Lorenzo
> You might want to look at relocating the inverter(s) closer to the meter
> instead of the array, one reason is even if there is some line loss at full
> power its less as the voltage goes up and the inverter does not see the
> line resistance that can cause high voltage issues at the inverter. Some
> engineers use more side of peak performance than full power, this keeps
> wite size down and does not effect output
> Jerry
>
> On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz"  wrote:
>
> Wrenches,
>
> We have a PV array situated about 900' from the POI (240V 1PH). We
> initially spec'd (5) 11.4kW inverters and the combined output would be
> 238A. The wire size required for this current over that distance is cost
> prohibitive.
>
> A solution was to use a single 50kW 3 phase inverter at the array and then
> convert it to 240V... somehow? Is anyone familiar with how to go about
> doing this? My thought was to have a step down transformer at the POI and
> pull off two legs to get 240V. Is this even a thing?
>
> The other, more expensive option is to use a step up transformer at the
> array and a step down at the POI to get us a smaller wire size.
>
> Thanks for any input.
>
>
> --
> *Loren Ortiz   Commercial PV Designer*
>
> lo...@cal-solar.com *  (530) 274-3671*
>
>
>
> 
> *Showroom located at: 149 E Main St. Grass Valley, CA 95945*
> ___
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.
> org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>
>
> ___
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.
> org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>
>


-- 













* Blake Gleason* - PE, LEED AP
*Director of Innovation & Technical Excellence*

*P:* 510.845.2997 x128
*E:* bl...@sunlightandpower.com
*W:* sunlightandpower.com 

See how universities are using business as a force for good with solar!

___
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or 

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Jerry Shafer]

Lorenzo
You might want to look at relocating the inverter(s) closer to the meter
instead of the array, one reason is even if there is some line loss at full
power its less as the voltage goes up and the inverter does not see the
line resistance that can cause high voltage issues at the inverter. Some
engineers use more side of peak performance than full power, this keeps
wite size down and does not effect output
Jerry

On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz"  wrote:

Wrenches,

We have a PV array situated about 900' from the POI (240V 1PH). We
initially spec'd (5) 11.4kW inverters and the combined output would be
238A. The wire size required for this current over that distance is cost
prohibitive.

A solution was to use a single 50kW 3 phase inverter at the array and then
convert it to 240V... somehow? Is anyone familiar with how to go about
doing this? My thought was to have a step down transformer at the POI and
pull off two legs to get 240V. Is this even a thing?

The other, more expensive option is to use a step up transformer at the
array and a step down at the POI to get us a smaller wire size.

Thanks for any input.


-- 
*Loren Ortiz   Commercial PV Designer*

lo...@cal-solar.com *  (530) 274-3671*




*Showroom located at: 149 E Main St. Grass Valley, CA 95945*
___
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive:
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org
___
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Kevin Pegg]

Curious some years ago I was asked to audit a system with a similar design. The 
question I was asked to answer is why the net kWh exported to the grid was much 
less than they hoped. The punchine was the idle load on the dry transformers 
were soaking up about 20% of the PV array's net production.

So from that lesson, I have made it a practice to avoid transformers if at all 
possible. In fact, a mini-grid retrofit we are doing now involves removal of 
numerous transformers and to consolidate with 120/208V for all but the deep 
well pumps and effluent plant we will keep at 600V.

What I concluded from this is better to run higher voltage DC lines for the 
long runs. Haven't had that situation come up again to test.

Have others looked into transformer losses?

Kevin

From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf 
Of Darryl Thayer
Sent: September-18-18 9:34 AM
To: newrewrenches 
Subject: Re: [RE-wrenches] Step-up/Step-down Transformer question

The single phase - 3phase change is too difficult and expensive.  Stay with 
single phase.  I have done this successfully with a step up and down 
transformer.  You, of course, need to select the correct transformer.  
Transformers seem to have a price advantage using standard voltages.  For 
example, starting at building 240 to 480 and then use 480-volt inverters.  This 
will require longer strings for the 480-volt single phase inverter.   another 
way is to use 240 to 240-480-volt and carry a neutral.  then select inverters 
that can operate with no neutral, I call them floating output.  This cuts 
current in half, voltage drop or rise by 1/4 allowing smaller wire.

On Mon, Sep 17, 2018 at 11:42 AM Lorenzo Ortiz 
mailto:lore...@cal-solar.com>> wrote:
Wrenches,

We have a PV array situated about 900' from the POI (240V 1PH). We initially 
spec'd (5) 11.4kW inverters and the combined output would be 238A. The wire 
size required for this current over that distance is cost prohibitive.

A solution was to use a single 50kW 3 phase inverter at the array and then 
convert it to 240V... somehow? Is anyone familiar with how to go about doing 
this? My thought was to have a step down transformer at the POI and pull off 
two legs to get 240V. Is this even a thing?

The other, more expensive option is to use a step up transformer at the array 
and a step down at the POI to get us a smaller wire size.

Thanks for any input.


--
Loren Ortiz   Commercial PV Designer

lo...@cal-solar.com  (530) 274-3671
  
[https://docs.google.com/uc?export=download=0B6l5VcsZgAv3TXRfSkhpZUNaczQ=0B6l5VcsZgAv3djFpMk9EQUdEdmg1K0hFdHBNZVlTZ3RZdW5VPQ]


[http://californiasolarco.com/wp-content/uploads/2018/06/CalSolarADVOCATE.png]
Showroom located at: 149 E Main St. Grass Valley, CA 95945
___
List sponsored by Redwood Alliance

List Address: 
RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org
___
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Darryl Thayer]

DRakes suggestion has the advantage of the DC side is not a voltage
sensitive as the AC side and voltage drop is not as critical.  allowing
perhaps a 3%

On Mon, Sep 17, 2018 at 12:50 PM 
wrote:

> Another option would be to locate the inverters near the grid and run the
> DC at as high a voltage as possible. Have a separate run of wire for each
> of the 5 inverters. If you ran the DC at 500 V, an 11.4 kW inverter would
> only draw 22.8. A. Use 2/0 AL for a little over 1% VD at full power.
>
>
>
> - Original Message -
> From:
> "RE-wrenches" 
>
> To:
> "RE-wrenches" 
> Cc:
>
> Sent:
> Mon, 17 Sep 2018 09:42:01 -0700
> Subject:
> [RE-wrenches] Step-up/Step-down Transformer question
>
>
> Wrenches,
>
> We have a PV array situated about 900' from the POI (240V 1PH). We
> initially spec'd (5) 11.4kW inverters and the combined output would be
> 238A. The wire size required for this current over that distance is cost
> prohibitive.
>
> A solution was to use a single 50kW 3 phase inverter at the array and then
> convert it to 240V... somehow? Is anyone familiar with how to go about
> doing this? My thought was to have a step down transformer at the POI and
> pull off two legs to get 240V. Is this even a thing?
>
> The other, more expensive option is to use a step up transformer at the
> array and a step down at the POI to get us a smaller wire size.
>
> Thanks for any input.
>
>
> --
> Loren Ortiz   Commercial PV Designer
>
> lo...@cal-solar.com *  (530) 274-3671*
>
>
>
> 
> *Showroom located at: 149 E Main St. Grass Valley, CA 95945*
>
> ___
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>
___
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org

Re: [RE-wrenches] Step-up/Step-down Transformer question

[Darryl Thayer]

The single phase - 3phase change is too difficult and expensive.  Stay with
single phase.  I have done this successfully with a step up and down
transformer.  You, of course, need to select the correct transformer.
Transformers seem to have a price advantage using standard voltages.  For
example, starting at building 240 to 480 and then use 480-volt inverters.
This will require longer strings for the 480-volt single phase inverter.
 another way is to use 240 to 240-480-volt and carry a neutral.  then
select inverters that can operate with no neutral, I call them floating
output.  This cuts current in half, voltage drop or rise by 1/4 allowing
smaller wire.

On Mon, Sep 17, 2018 at 11:42 AM Lorenzo Ortiz 
wrote:

> Wrenches,
>
> We have a PV array situated about 900' from the POI (240V 1PH). We
> initially spec'd (5) 11.4kW inverters and the combined output would be
> 238A. The wire size required for this current over that distance is cost
> prohibitive.
>
> A solution was to use a single 50kW 3 phase inverter at the array and then
> convert it to 240V... somehow? Is anyone familiar with how to go about
> doing this? My thought was to have a step down transformer at the POI and
> pull off two legs to get 240V. Is this even a thing?
>
> The other, more expensive option is to use a step up transformer at the
> array and a step down at the POI to get us a smaller wire size.
>
> Thanks for any input.
>
>
> --
> *Loren Ortiz   Commercial PV Designer*
>
> lo...@cal-solar.com *  (530) 274-3671*
>
>
>
> 
> *Showroom located at: 149 E Main St. Grass Valley, CA 95945*
> ___
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>
___
List sponsored by Redwood Alliance

List Address: RE-wrenches@lists.re-wrenches.org

Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: 
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out or update participant bios:
www.members.re-wrenches.org

Re: [RE-wrenches] Low voltage DC v. higher voltage DC

[Marco Mangelsdorf]

Mahalo Mike.

Can you tell us please when the SS will actually be able to integrate the
BYD battery platform in the north American market?

marco

On Monday, September 17, 2018, Harry Mahon 
wrote:

> Marco and all – yes that is the correct spec sheet for the BYD batteries
> that will work with Sunny Boy Storage.
>
>
>
> SMA strongly would recommend the Sunny Island for off-grid in general and
> certainly whole home backup.  See the attached from Home Power April/May
> 2011; quad stack of SIs acting as UPS for the home – just charging
> batteries when grid is present, powering home with batteries/PV when grid
> is gone.  A dual split phase cluster is almost 24,000 W continuous (!)
> capability and can handle crazy power factor loads with no issues.  Built
> in generator functions and two relay positions per Sunny Island allow for
> lots of redundancy and fail-safe load shedding to be built in.
>
>
>
> The Sunny Boy Storage (SBS) is designed to be a grid-tied inverter to
> allow higher self consumption of local PV power.  Even with the ABU to
> allow off grid operation (grid forming on its AC outputs rather than just
> on the dedicated 120VAC Secure Power Supply outlet), there can be a several
> second delay in the switch from grid power to microgrid as the ABU must
> signal the Sunny Boy Storage that it has disconnected from the grid and
> that it is safe for the SBS to form a grid on its output terminals.  Also
> be aware that there is no master-slave configuration ability with the SBS –
> they will always assume they are acting independently on their energy meter
> input information.
>
>
>
> Best regards –
>
> Mike
>
>
>
> SMA America
> Michael Mahon
> Technical Trainer, Solar Academy
> 6020 West Oaks Boulevard, Suite 300
>
> Rocklin, CA 95765
>
> U.S.A.
> Mobile:   +1 916 918 9412
> * www.SMA-America.com *
>
>
>
> Solar Academy: www.SMA-America.com/partners/sma-solar-academy/overview.
> html 
>
>
>
> Full training schedule: https://www.sma-america.com/
> partners/sma-solar-academy/seminars/trainings/training/list.html
>
>
>
>
>
> [image:
> http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/facebook.jpg]
>  [image:
> http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/twitter.jpg]
>  [image:
> http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/wordpress.jpg]
>  [image: Linkedin Logo]
>  [image:
> http://sma-planet.sma.de/fileadmin/fm-dam/infos/social_media/youtube.jpg]
>  [image:
> SMAAFORUM_ICON] 
>
> [image: cid:image008.jpg@01D43B9E.70803930]
>
>
>
>
>
> This email and any attachments thereto may contain SMA America, LLC
> confidential, privileged and private material for the sole use of the
> intended recipient. Any review, copying, or distribution of this email (or
> any attachments thereto) by others is strictly prohibited. If you are not
> the intended recipient, please contact the sender immediately and
> permanently delete the original and any copies of this email and any
> attachments thereto. Thank you.
>
>
>
> *From:* RE-wrenches  *On
> Behalf Of *Marco Mangelsdorf
> *Sent:* Saturday, September 15, 2018 10:08 PM
> *To:* 'RE-wrenches' 
> *Subject:* Re: [RE-wrenches] Low voltage DC v. higher voltage DC
>
>
>
> Sabaidee from Vientiane, Lao PDR.
>
>
>
> Attached is the spec sheet on the BYD battery in question.
>
>
>
> I’ve confirmed with SMA directly that there’s no capability for the Sunny
> Storage design (S.S., ABU and battery) to use a generator input.  My
> apologies for mis-stating earlier that it could accommodate a generator.
>
>
>
> As far as grid-tie with batteries, the Holy Grail as far as I’m concerned
> is being able to provide whole house back-up and not have to do the old
> fashioned and pain in the arse critical load sub-panel.  The more choices
> that we’re provided, the more better.  So I’m pleased that companies like
> SMA, Ensync, SolarEdge and others are bringing new equipment and designs to
> market to allow for whole house back-up.
>
>
>
> marco
>
>
>
> *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org
> ] *On Behalf Of *jay
> *Sent:* Saturday, September 15, 2018 5:00 AM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] Low voltage DC v. higher voltage DC
>
>
>
> HI Harry,
>
>
>
> The battery is charged from the AC side correct?
>
> And is the charging algorithm inside the ABU.
>
>
>
> If so why couldn’t you use a generator to charge the battery?
>
>
>
> jay
>
>
>
> peltz power
>
>
>
>
>
>
>
> On Sep 13, 2018, at 7:10 AM, Harry Mahon 
> wrote:
>
>
>
> Marco –
>
>
>
> The Sunny Boy Storage “Advanced Backup Unit” accessory or ABU will be
> discussed at SPI in a couple weeks – first