[RE-wrenches] Sunny Island Battery Disconnects

[Jason Szrom]

Hi William,

I don't have a lot of experience with battery OCPD, but I did have a project where we used a Square D heavy duty safety switch to protect a negative grounded 600VDC battery string. All of the heavy duty switches are AC and DC rated (H363, H364, H365...).

For DC applications, go here:  http://www.schneider-electric.us/sites/us/en/support/documents-downloads.page

And search for bulletin number 3110DB0401. This shows that the switches are listed for DC use if 2 poles are wired in series. 

You are correct that a grounded conductor can never have OCPD unless the OCPD opens both the grounded and ungrounded wires at the same time (NEC 240.22). This could only be accomplished with a multi-pole circuit breaker and there aren't many around rated for 600VDC.

Hope this helps.

Regards,

Jason M. Szrom, PE
Engineering Supervisor
Solar Energy Systems, LLC
718-389-1545 x13

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Ray Walters
Sent: Sunday, February 09, 2014 4:22 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Sunny Island Battery Disconnects

Yes, they make a 3 pole class T fused disconnect.  You could have 3 
strings fused separately and then combined in a single pull disco, UL 
listed too. I even have one here, or I can provide their contact info.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 2/8/2014 6:59 AM, Richard L Ratico wrote:
> Ray,
> Way back in 2002, you mentioned using Boltswitch products for battery string
> fusing
> immediately outside the battery box. Might one of these be a partial solution
> for William?
>
> Dick Ratico
> Solarwind Electric
>
>
> --- You wrote:
> I'm working on something similar.  I think the Flex 1000 is the only
> reasonable choice that can handle more than 2 of the large format DC
> breakers.  Midnite has the more expensive MNBCB -1000 Battery Combiner
> box,  but there just isn't enough documentation to figure out what it
> can and can't do.
>
> R.Ray Walters
> CTO, Solarray, Inc
> Nabcep Certified PV Installer,
> Licensed Master Electrician
> Solar Design Engineer
> 303 505-8760
>
> On 2/7/2014 6:29 PM, william at millersolar.com wrote:
>> Friends:
>>
>> I am reworking an installation with 3 Sunny Island inverters.  The
>> battery leads have no disconnecting means or OCP.  I have been looking
>> for sensible hardware to provide this and I have found some options.
>> I am interested in any input on these or ideas I have not discovered.
>>
>> 1.SMA BATFUSE.  I am having trouble deciding which one is right for a
>> 3 SI install.
>>
>> a.The B.003 appears to have fuse positions for the positive and the
>> negative leads.  I am fairly darn certain I don't want fuses in the
>> negative leads of a negative bonded system, and although this is my
>> first SI install, I am pretty sure this is negative bonded.  Am I
>> missing something here?
>>
>> b.The B.001 has only positions for two fuses as far as I can see from
>> the manual.
>>
>> c.So it looks like neither will work for me.  Does anyone have any
>> experience and/or wisdom here?
>>
>> 2.Midnite Solar E-panels:
>>
>> a.The regular panel has DC and AC components.  I want to control the
>> AC elsewhere so I could order three slave units.  The Midnite unit
>> mounts right under the inverter but I would prefer to have the OCP
>> closer to the batteries.
>>
>> 3.Outback:
>>
>> a.We could purchase an Outback FX1000 and install three breakers in it.
>>
>> 4.Breaker Size:
>>
>> a.I have started to read the manual but I have yet to find out what
>> size breaker fuse is recommended.  Have I just not found it yet?
>>
>> b.Also, I have not found a specification for battery cable size.  Am I
>> blind?
>>
>> Thanks in advance.  I really appreciate the help I receive here.  I
>> try to give as well as receive.
>>
>> William
>>
> --- end of quote ---
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change email address & 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

Change email address & 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


-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.3462 / Virus Database: 3697/7073 - Release Date: 02/07/14