There are three ways to wire a solar panel array; series, parallel, and series-parallel. If the needs of your solar electrical system call for parallel wiring of your solar panels, this blog post will teach you how to wire your solar panel array in parallel.
Wiring solar panels in parallel simply means combining all of the positive wires together into one wire that will go to the charge controller and combining all of the negative wires together into one wire that will go to the charge controller.
To combine the wires from the solar panels, you will need to use MC4 branch connectors.
- 2 to 1 MC4 Branch Connector
- 3 to 1 MC4 Branch Connector
- 4 to 1 MC4 Branch Connector
- 5 to 1 MC4 Branch Connector
Depending on your choice of panels, you may also need to incorporate fuses into your parallel wired solar panel array.
- 15 Amp MC4 Fuse
- 20 Amp MC4 Fuse
All of the diagrams below show a parallel wired solar panel array with fuses in their proper place. If your setup does not need fuses, simply ignore the fuses and connect the positive wires directly to the branch connector.
How to Wire Two Solar Panels in Parallel
How to Wire Three Solar Panels in Parallel
How to Wire Four Solar Panels in Parallel
How to Wire Five Solar Panels in Parallel
rob paul
Saturday 7th of August 2021
Hi Nate - I'm looking to run 3x Renogy 175w Mono panels (Optimum Operating Current 9.75A) into a Victron SmartSolar MPPT 250/100-Tr Solar Charge Controller 250V 100A with Bluetooth. The distance from the Walfront 2P 63A breaker (what was in stock) you recommend to the controller is about 2ft. The distance from the controller to the inverter is about 3 ft. I can't seem to get a ferruled 6 awg cable into the Solar controller as you recommended in the diagram I purchase.
Can you advise if an 8awg cable is acceptable?
rod browne
Tuesday 18th of May 2021
Hi Nate, I'm going to install one of your designs on the flybridge roof of my boat (2 panels, one string to start with and work up to 6-8 panels, two strings) and want to install the end product wiring size requirements at the start. My round trip wire run is about 80 feet with some constriction getting off the roof. Smallest wire size from panels to controller will be needed. Anticipating Renogy 160W (if they are still available) or Renogy 175W panels to Victron 100/50. I'm a bit confused however about where and when I should wire series or parallel or series/parallel with the branch connectors to minimize the wire size requirements getting off the roof. Can you offer suggestions or advice? Thanks, Rodd Browne
Nate Yarbrough
Sunday 23rd of May 2021
You want your solar array voltage to be at LEAST 20V higher than your battery bank charging voltage and you solar array amperage under 30V so you can use MC4 connectors. To do this, you'll have to do some form of series parallel to make this possible. Pure series would exceed the max solar input voltage of your 100/50.
Chris
Thursday 25th of March 2021
Hello Nate, love this blog. Can I wire 3 200W panels going one>two>Three using two 2 to 1 MC4 Branch Connectors? Thanks, Chris
Andrew
Monday 28th of December 2020
Hey! I have three Renogy 100w panels that I am looking to wire in parrallel. Do you recommend adding fusing before my positive 3 to 1 branch connector? Thankyou!!!!
Nate Yarbrough
Tuesday 29th of December 2020
Those would, indeed, need to have fusing before the branch connector.
Ron
Sunday 13th of September 2020
Do I need a double pole circuit breaker for both the positve (red) and neutral(black) cable going to the charger controller as you showed in one of your diagrams or can I just use an inline fuse on the positve cable to the MPPT? Thanks!
Nate Yarbrough
Monday 14th of September 2020
The dual pole disconnect as per my diagrams is in accordance with NEC 690.17 (B).