[RE-wrenches] paralleling FM-60's

[jay peltz]

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
> 
>