panel wiring

[pabear89]

short information, have a 12v system working for my rv and it is doing well.
Now installing a 48v set up for the off grid cabin.
6000w 48v EG4 with 12 400w panels, with 6 eg4 100a batteries purchased a kit.
it came with a disconnect switch with 2 inputs but only one pair of cable to panels, they are connected in series' and seem to be working.
would it be worth getting a separate pair of cables to break the panels into 2 sets of 6 wired in series? would this help in keeping the battery bank charged or a waste of time and money.

Am I chasing my tail? Have been reading A LOT here but finally got the point of asking. thanks

 

[42OhmsPA]

What's the VoC of the panels?
I bet your are pushing the limits of releasing the magic smoke with 12 in series and would strongly recommend 6s2p.

 

[pabear89]

Label says 36.87
panels installed per instructions for what good it was. lacks clarity, and was only sent one pair but a double sided switch.
which is why i am questioning it, one would think that they would have sent more cables as it was purchased as a kit.

 

[42OhmsPA]

Label says 36.87
panels installed per instructions for what good it was. lacks clarity, and was only sent one pair but a double sided switch.

Are you sure that's VoC and not VmP?
Please share a photo.

What's the record cold temp for the past century in your area?

 

[pabear89]

tag says voltage open circuit 36.87 went back out and looked.
lowest temp so far here has been mid teens. but that could change.

 

[zanydroid]

ASHRAE data is the scientific way to do this (or is the weather almanac better? ASHRAE is for HVAC and HVAC doesn’t smoke with overly low temps like solar does)

ASHRAE climatic design conditions 2009/2013/2017/2021

ASHRAE climatic design conditions station finder

ashrae-meteo.info

And adjust down based on your experience since they only have data for various landmarks, there could easily be local coldspots

 

[42OhmsPA]

tag says voltage open circuit 36.87 went back out and looked.
lowest temp so far here has been mid teens. but that could change.

This should help you immensely.

MidNite Solar - Classic Sizing Tool.

MidNite Solar is the industry leader and manufacture of quality Renewable Energy System electrical components and E-Panels.

www.midnitesolar.com

Personally I'd wire them 6s2p and contact SS if you didn't get everything that was ordered / advertised.
Iirc that inverter can handle 27a on the mppt so you'd be well within the limits.

@Markus_EG4 what are your thoughts?

 

[pabear89]

looks like i will be getting more cables and splitting the panels into 2 sets of 6.
just to be safe.

 

[Markus_EG4]

This should help you immensely.

MidNite Solar - Classic Sizing Tool.

MidNite Solar is the industry leader and manufacture of quality Renewable Energy System electrical components and E-Panels.

www.midnitesolar.com

Personally I'd wire them 6s2p and contact SS if you didn't get everything that was ordered / advertised.
Iirc that inverter can handle 27a on the mppt so you'd be well within the limits.

@Markus_EG4 what are your thoughts?

I agree with you

 

[pabear89]

So I got another pair of cables, 100 ft premade ends from SS.
The kit came with 50 ft but when I ordered it I added the 100 pair because eyeballing the spot for the panels
was close but not best location. Glad too because the 100 is just right to get to the far end, where the neg leads are.

Fished them in the conduit and have them ready to make connections, have a fused end for each pos lead once I remove the pair coupler. thought i would ask before i did something bad here, The pos cables are about 24 feet longer than needed.
Would it do any harm in cutting the extra length out of them?
My ocd is wanting to make the install look nice, but if it will create an imbalance i would find away to hide the extra coils of wire.

 

[42OhmsPA]

Snip snip.
As long as the length between panel to panel connections the same you are ok, the homeruns don't matter.

 

[pabear89]

yep panel to panel is all same. this is main leads from panel array to disconnect switch.
using all of the neg lengths but the end with the pos connection is 24 feet closer to building and the extra coils look like i was just lazy on the install. Thanks Much.

 

[42OhmsPA]

No problem. If your panel leads are long enough use the leapfrog wiring next time.