[RE-wrenches] One renewable disconnect.

[Darryl Thayer]

I hope i do not muddy the water here.  if you have 3 phase delta, usually the 
single phase transformer is larger, can you do the solar in split phase?  


Also staying with the 3 phase, why not use a three pole service rated switch to 
Line side tap, and use two poles for the single phase and the third pole for the 
high leg.  After the 3 pole switch, use a 2 pole switch for the wind turbine 
(breaker in a box) , and a three pole sw in a box for the 3 phase solar.   .  





________________________________
From: John Wadley <wadleyjk at hotmail.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Sent: Wed, March 2, 2011 3:36:19 PM
Subject: [RE-wrenches] One renewable disconnect.

Wrenches,
      I am designing a system with both wind and solar backfeed and I'm having 
an issue with the utility.  They say we need to have a single renewable 
disconnect switch before the grid backfeed.  The solar is designed to backfeed 
3-phase through a meter, then a fused AC disconnect to the line-side to avoid 
upsizing the MDP.  The wind inverter output is 120/240V split-phase (10A) which 
I had planned to do load-side backfeed through a wind meter with a seperate AC 
disconnect since it was so small.  To meet the single renewable disconnect 
requirement, I'm thinking I may need to backfeed the wind on the load-side to 
one of the three phases.  I guess my question is can I use a single 5 pole fused 
AC disconnect to control both with one switch handle or is that an NEC violation 
wrt to merging separate systems within the same conduit?  Or, should I keep them 
in separate switch boxes with some kind of gang handle?  I have a 3-phase 
aggregation panel for the solar inverters (6 total, 2 per phase, 240 delta), but 
if I integrate the wind there in order to simplify the AC disconnect issue, the 
solar meter will register both solar and wind production.  What is the best 
practice in this situation?

Thanks,
John Wadley, MSEE, PE
NABCEP Certified Solar PV Installer (TM)
Wadley Engineering
214-557-3841

CONFIDENTIALITY: This communication, including attachments, is for the exclusive 
use of the addressee(s) and may contain proprietary, confidential or privileged 
information. If you are not the intended recipient, any use, copying, 
disclosure, or distribution or the taking of any action in reliance upon this 
information is strictly prohibited. If you are not the intended recipient, 
please notify the sender immediately and delete this communication and destroy 
all copies.


      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20110302/4bb9ec92/attachment-0004.html>