Are All MC-4 Connectors 12 Gauge ?

[SV Demeter]

With my solar install I am going to use MC-4 cables and will likely buy an extension set to get from the panels to the controller. Im concerned about voltage drop. All the MC-4 cable extensions I have been looking at seem to be 12 gauge wire. I will have (4) 100 watt panels. (2) on each side of the boat. The run from the strbd side panels to the controller im estimating at 18', one way so 36' round trip. Im thinking I would be better off with 10 or even 8 gauge wire? So should I just use the MC-4 cables to get me through the deck and then step up the wire to 8 gauge or are there heavier gauge MC-4 cables available? The run on the port side to the controller should not be more than 10' round trip so I guess 12 gauge would be fine there?

[Islander]

I just cut a 50' MC-4 extension cable in 2 to run from the panel to the controller. I'm seeing anywhere from 27 to 34 volts at the controller. I run 6 gauge from the controller to the 12 volt batteries 4' away with no voltage drop - this is where you need the bigger wire. I'm using MPPT, if you're using PWM you might need to do something different?

Cheers

[btrayfors]

If you run the panels in series instead of parallel, and you have a good MPPT controller, then for a given wire size there will be less voltage drop and more efficient charging under most conditions.

Bill

[SV Demeter]

So it sounds like all MC-4 cables are in fact only 12 gauge then. I will likely be running a series parrallel configuration so the voltage on the pair should be something like 36-40 volts. I will be using an Outback Flexmax 60 charge controller which is MPPT so perhaps there is no need for me to be concerned with voltage drop here?

[Cotemar]

SV Demeter,

You can buy the MC4 connectors in either 10 or 12 gauge.

MC4 Connector

http://www.cruisersforum.com/forums/...tml#post488059

http://www.cruisersforum.com/forums/...tml#post491749

Mark