Adding Solar to my existing system

[Dustin Henderson]

Regarding my travel trailer, it was pre wired for solar. 8 AWG runs from roof panels to my SCC.

I have 4x100 Watt panels arrayed in a 2s2P. They feed a Renogy 100/40 MPPT. This has worked flawlessly since install. Yes, the Renogy SCC has performed flawlessly.

I am considering upgrading my battery (capacity), and adding an ATS inverter (using pre wired loop which powers a limited number of receptacles).

But this question is related to paneling. By my thoughts, I am fine to slightly over panel to 600W in a 3s2P configuration in terms of both wiring and SCC. Am I correct?

Panel specs:
Maximum Power at STC: 100W
Cell Efficiency: 22.00%
Optimum Operating Voltage (Vmp): 20.4V
Open-Circuit Voltage (Voc): 24.3V
Optimum Operating Current (Imp): 4.91A
Short-Circuit Current (Isc): 5.21A
Operating Temperature: -40°F to 176°F
Maximum Series Fuse Rating: 15A
Certifications: CE, ISO
Maximum System Voltage: 600V DC (UL)
Weight: 14.1lbs/6.4kg
Dimensions: 41.8 x 20.9 x1.38 in
Panel Leads (Pair): 14 AWG

 

[SunDave]

Hi. How is that over paneling? Wouldn't it land at about 75 volts open circuit and 10.42 amps? Both are within your controller rating unless I did the math wrong. 8 gauge wire is plenty overkill to carry 10 amps.

Keep in mind that adding equipment like the inverter, or drawing more from the system will change it drastically. It would be a good idea to have a shutoff switch on the inverter and keep it off when not in use. Otherwise just the idle draw can overwhelm a 600 watt RV system. They are rarely angled correctly for max production, and can get shading issues like any other system.

 

[Dustin Henderson]

Hi. How is that over paneling? Wouldn't it land at about 75 volts open circuit and 10.42 amps? Both are within your controller rating unless I did the math wrong. 8 gauge wire is plenty overkill to carry 10 amps.

Keep in mind that adding equipment like the inverter, or drawing more from the system will change it drastically. It would be a good idea to have a shutoff switch on the inverter and keep it off when not in use. Otherwise just the idle draw can overwhelm a 600 watt RV system. They are rarely angled correctly for max production, and can get shading issues like any other system.

Inverter would be off all the time except 2 or 3 occasional uses per year.

It's over paneling in the sense that the literature indicates The Renogy Rover 40 Amp MPPT solar charge controller has a maximum solar input power of 520W for a 12V system