I meant the question largely to be a generic one but I can give you an example:
Buried conductors are 6AWG. No additional grounding conductor exists between
the main and detached building. As Brian Mehalic already responded, the 60A
subpanel would tough to deal with for inverter sizing. Assume the AC disconnect
is required near the main meter and so would have to disconnect all circuits in
the subpanel.
So say we put a 50A main breaker in the 60A subpanel to allow a Fronius IG 3.0
(3000 watt) and a string of 12 Sharp ND240s or similar.
The PV ground would have to hit a ground rod at the garage and a grounding
conductor would need to be buried back for bonding at the main building--right?
----- Original Message -----
From: Mark Frye
To: RE-wrenches
Sent: Wednesday, April 11, 2012 9:25 AM
Subject: Re: [RE-wrenches] Grid tied PV to subpanel on detached garage?
1 - What is the AC output rating of the PV inverter?
2 - What is the size of the feeder conductors?
3 - Does the sub panel at the garage have a main breaker of it's own?
4 - Does your AHJ or utility require anAC disconnect or not?
Mark Frye
Berkeley Solar Electric Systems
On 4/11/2012 7:09 AM, Aladdin Solar wrote:
Wrenches:
There's probably an obvious answer but please help me think this through.
Here's the situation--comes up all the time: The PV array and grid-tied
inverter will be located on a detached building (garage or pole barn, etc.).
The existing power to the building is a 240V 60A subpanel connected to the main
panelboard at the house or main building via buried cable. If we obey buss bar
loading and wire sizing, etc, is there any reason why we can't or shouldn't
install the small grid tied PV system and tie it into the garage subpanel
instead of trenching new lines back to the house and hit the main panel there?
One hitch I see is that if we want a PV system AC disconnect near the main
meter, the whole garage would end up on that. Have I overlooked an NEC or
inverter requirement?
Thanks for your comments.
Charlie Pickard
Aladdin Solar
__________ Information from ESET NOD32 Antivirus, version of virus
signature database 7045 (20120411) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
_______________________________________________
List sponsored by Home Power magazine
List Address: [email protected]
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 7045 (20120411) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
------------------------------------------------------------------------------
_______________________________________________
List sponsored by Home Power magazine
List Address: [email protected]
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 7045 (20120411) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 7045 (20120411) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
_______________________________________________
List sponsored by Home Power magazine
List Address: [email protected]
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
