diy solar

diy solar

Combiner box?

I almost ordered that and went with a mod it’s MNPV-6


I don’t know if this is certified for Canada, but I would not doubt it is.

I did not like the Ecoworthy for a couple of reasons. Mostly because it was pre-built for additional stuff they sold, which was not what I was using.

The first was the MC4 connectors on the outside. THat’s just an extra failure point. Instead, for the Midnite, the same hole is there except I install a cable gland in the hole I run wire all the way from the roof through the cable gland which gets connected directly to the circuit breaker.

For the midnite, I bought the exact circuit breakers I wanted, which as you and and take off panels can change. The Ecoworthy I was stuck to the C/B that came with it. If you don’t use a series of 100 watt 18 volt panels, more than likely you won’t require 10 amps.

Also, with the Midnite, I wired it the way I wanted. I ended up putting the panels 3S2P, but I plan on growing that to at least 3S3P. My original plan I bought it for was 6P.

I think the last part was the Midnite 150 VDC circuit breakers I installed were rated for constant shut off. When I store my RV between trips, the circuit breakers are rated to turn on and off as many times as needed. I’m not sure the Ecoworthy was rated for that. I may literally trip these circuit breakers 50 times per year for storage and maintanence, and for getting some power while wiring on projects while stored.
Thanks Chrisski, in fact I decided the same thing you did, and bought the same midnite solar you did!

My plan is 4s3p (180w 12v panels wired for 24v) 10 awg to the combiner.

Question: any safety reason I couldn't install the combiner inside my house close to my Growatt?
 
Question: any safety reason I couldn't install the combiner inside my house close to my Growatt?
I can't say on that. I did install my combiner in the pass through storage in my RV.

Once you start mentioning house, there's codes I'm not familiar with.
 
I ended up using 12 awg wire from the roof to the combiner box (~25 feet each string). Each string is ~100v and ~8.5a and connected to a 15amp breaker. The combined output is ~100v at ~25a and that goes from the combiner to the MPP Solar LV2424 via 6awg wire (about 2 feet). No issues over the last six months.

I think given your specs above I would also run 4S3P as you mentioned. If you series 4 panels together you would need a total of six wires from the panels to the combiner box which is what I have as well. That would give you strings at ~72v and 10a, and combined ~72v at ~30a.

Just to be sure I hacked together a diagram connecting the 12v 180w panels into 3 series of 4 panels.

I've psyched myself out between 3s4p and 4s3p!

Is this correct? And is it suitable for a 24v growatt?
 

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