12AWG Wire from Victron 20A MPPT?

[PhotogTX]

I have very confined space in a battery compartment that I built and went with the Victron 100-20 MPPT due to its small footprint. My panel is a single Renogy 175W. Between my +/- bus bars and MPPT is a 25A circuit breaker. The distance between the MPPT and bus bars is less than two feet, so I was curious if I'd be okay running 12AWG wire from the Victron to the breaker and bus bars. 12AWG is good for 25A up to a distance of six feet, but thought I'd see if 12 is okay or if I should I use 10AWG. I have plenty of 12 on-hand, but I'd rather be safe that sorry before I make my final terminations.

 

[yodamota]

SO one thing to think about with your current 175W panel is that it will only ever be able to deliver a max of 175w / 14vdc = 12.5amps. So with your current 12awg wire this seems fine.
However its usually best to use the biggest wire you can...

 

[chrisski]

12 AWG is fine for ampacity and meets the 1.25 rule with 20 amps *1.25 amps = 25 amps.

 

[ericfx1984]

Have you tried looking up some charts? Is this 12 gauge wire OFC or CCA?

 

[pollenface]

According to my deadly calculator, you can expect a 0.5% voltage drop @ 14.6v/12.5a

If you use a smart battery sense it will tell the controller to compensate for voltage drop (and temp if required).

 

[PhotogTX]

Have you tried looking up some charts? Is this 12 gauge wire OFC or CCA?

Its THHN stranded copper, no copper clad aluminum. My reference chart is the one by Blue Sea Systems.

 

[PhotogTX]

Thanks to everyone who responded. For right now, I'll go with the #12 THHN wire to get things set up. The Victron MPPT will accept a max size of #10, but with a ferrule the #10 will not go into the terminals, but #12 will. Then there's the whole ferrule or not-to-ferrule debate. Thanks again, everyone.

 

[yodamota]

Then there's the whole ferrule or not-to-ferrule debate.

oh no lets not bring that into this thread as well LOL

 

[PhotogTX]

I went with the #12 wire to/from the Victron...everything seems to be working as expected.

 

[Q-Dog]

You should be OK, but ... If you ever add more panels and push that controller to its full capacity, you will want to use finer stranded wire. According to Victron, THHN isn't fine enough ... and my own experience agrees with that. I installed a 100/20 with THHN and it was OK until I added more panels and pushed the unit to it's full output capacity. It ran a little bit hot.

If you have trouble finding it, West Marine sells fine-stranded 10 AWG by the foot.

1. Safety precautions

www.victronenergy.com