[RE-wrenches] DC Rating of Disconnects

[Peter Parrish]

Peter T. Parrish, Ph.D., President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com 

  _____  

From: Peter Parrish [mailto:peter.parrish at calsolareng.com] 
Sent: Friday, November 21, 2008 9:10 AM
To: 'RE-wrenches'
Cc: 'Peter Parrish'
Subject: DC Rating of Disconnects

 

I am looking into using the PV Powered PVP2000 inverter for some small, low
voltage designs. The string Voc will be around 200 Vdc, worst case.

 

Since the PVP2000 doesn't come with a DC disconnect, I am wondered what
other wrenches who install the PVP2000 have been doing about this. I hate to
spend $150 on a 600 V AC/DC disco such as the SD HU361RB to provide the
means of disconnection. I believe that the 240 V AC discos such as the SD
DU221RB have no DC rating.

 

>From an academic point of view, I wonder why the smaller discos are not dual
rated, since we all know that the real-time voltage difference in a 240 V AC
system can be 41% greater than 240 V.

 

In any event, any Code-compliant solutions would be greatly appreciated.

 

- Peter

Peter T. Parrish, President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20081121/34d2b164/attachment-0002.html>