[RE-wrenches] AC breakers used in DC applications

Kurt Albershardt info at es-ee.com
Fri May 14 21:59:14 PDT 2010


The Square-D catalogs are marginally clear on which breakers are listed for DC and for what voltages, but when I tried to select an appropriate load center for a DC application earlier this year I quickly ran into a number of conflicts in their catalogs.  Here is the response from Schneider tech support (Case# 4845778 on 1/19/10 in case anyone runs into problems with an inspector):



The load center catalog numbers listed below are UL LISTED, File E6294, for use on 48 V dc systems. The load centers listed ARE NOT MARKED for use on this voltage system, however are suitable for the application. QO branch breakers, 10-70 ampere (1 and 2 pole) are also UL LISTED for use on 48V dc systems. Short circuit current rating is limited to 5,000 amperes when used on 48V dc.
QO24L70F, S or RB QO612L100F, S, DF, DS, DFCU, DSCU, RB, TRB or RBCU QO816L100F, S, DF, DS, DFCU, DSCU, RB or RBCU
QO112L125G or QO11224L125G QO116L125G QO11624L125G QO120L125G QO12024L125G QO124L125G or QO12030L150G QO124L150G QO130L150G or QO112L200G or QO130L200G or QO13040L200G QO142L225G or
GRB or GRB
or GRB
GRB
GRB GRB GRB or GRB QO142L225GRB


I can email the PDF to anyone who needs a copy.

 


On May 13, 2010, at 18:24 , Darryl Thayer wrote:

> I thought the Sq.D QO for sizes up to 60 amp was rated for DC?  and only the Square D  
> Also why not use DC breakers? Robin makes some very small breaker boxes, and he alos has high voltage breakers,  (at least 250 volt? DC)
> Darryl
> 
> --- On Thu, 5/13/10, William Miller <william at millersolar.com> wrote:
> 
> From: William Miller <william at millersolar.com>
> Subject: Re: [RE-wrenches] AC breakers used in DC applications
> To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> Date: Thursday, May 13, 2010, 7:18 PM
> 
> Bill:
> 
> I thought the rule of thumb was:  Don't do it.
> 
> William Miller
> 
> 
> 
> At 05:10 PM 5/13/2010, you wrote:
>>  
>> Fellow Wrenches,
>>  
>> Some time ago, Windy Dankoff had a rule of thumb to substitute (conservatively) an AC breaker for use in a DC application. 
>>  
>> Is anybody's memory, or perhaps even the old dog himself; if he is listening, better than mine?
>>  
>> TIA,
>>  
>> Bill Loesch
>> Solar 1 - Saint Louis Solar
>> 314 631 1094
> 
> -----Inline Attachment Follows-----
> 
> _______________________________________________
> List sponsored by Home Power magazine
> 
> List Address: RE-wrenches at lists.re-wrenches.org
> 
> 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
> 
> 
> _______________________________________________
> List sponsored by Home Power magazine
> 
> List Address: RE-wrenches at lists.re-wrenches.org
> 
> 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
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100514/c4a1b8d1/attachment-0003.html>


More information about the RE-wrenches mailing list