[RE-wrenches] paralleling FM-60's

[R Ray Walters]

I second Allan's move to 48 v; that's usually what we've ended up doing in very similar situations, to keep the existing 'monsta' cable.
Usually they have a dated mod sine inverter, so the upgrade to Outback improves the system coming and going.
As much as I loved the SW series inverters, their time has come and gone. They don't last forever, and even if parts are available, they're almost $1200 to repair.

R. Walters
ray at solarray.com
Solar Engineer




On Oct 20, 2010, at 12:37 PM, Allan Sindelar wrote:

> Jay,
> When we faced this issue recently, we used it as an opportunity to upgrade to a 48V system. The obsolescence and lack of Schneider support for the SW4024 contributed to the logic of this approach.
> 
> At 48V an MX60 will handle 3200 watts.
> 
> Allan Sindelar
> Allan at positiveenergysolar.com
> NABCEP Certified Photovoltaic Installer
> EE98J Journeyman Electrician
> Positive Energy, Inc.
> 3201 Calle Marie
> Santa Fe, New Mexico 87507
> 505 424-1112
> www.positiveenergysolar.com
> 
> On 10/20/2010 11:58 AM, jay peltz wrote:
>> 
>> Hi Ray et all,
>> 
>> The customer has 200' of 4/0 direct buried with a 24v system, and is running close to 60 amps now, and wants to add 6 more 215 watt modules.
>> So the issue has been to try and find a way around putting in another wire ie digging a new trench through his yard.
>> 
>> the client may be willing to try and see how it goes with the controllers, at this point hes aware that it could blow up and its not a warranty issue.
>> 
>> Will keep you up to date about what smokes or not.
>> 
>> j
>> 
>> peltz power
>> 
>> On Oct 20, 2010, at 10:18 AM, R Ray Walters wrote:
>> 
>>> Hi Jay;
>>> 
>>> I'd second (3rd, 4th?) everyone else's comments that it probably isn't a good idea.
>>> I'd add that the diode will eat at least a volt, so that's not good for MPPT, or balancing.
>>> The one possible way to do this, might be to use a Vanner battery equalizer, which is designed to split an incoming charge source, and feed 2 batteries, without letting them 
>>> "see" each other. I think they're only good for 24 v, though, so that might not work for your situation. 
>>> The only other way I could see, is using a huge relay ( or paralleled relays) controlled by a C40 (or similar). You would lose both MPPT and PWM, and be back in the solar stone age (90s) though.
>>> 
>>> TIme to pull out the 2 big cables, and pull 4 smaller ones?
>>> Have fun, I actually like retrofitting old off grid stuff; it presents all sorts of interesting challenges like this.
>>> 
>>> R. Walters
>>> ray at solarray.com
>>> Solar Engineer
>>> 
>>> 
>> _______________________________________________
>> 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/20101020/7799cf2f/attachment-0003.html>