MC4 Connectors?

[jrnymn7]

I'm looking to extend the cables on my solar panels, and may want to bump up awg size with them.

??? Can 12awg and 10awg MC4 connectors be connected, or are they different in size, and therefore cannot be connected?

thanks!

[jrnymn7]

Thanks, Muddy,

yeah, I already ordered four 5' cables with mc4 on one end only. If they become troublesome, I will do as you suggest, and simply butt the cables together.

[Muddydogs]

jrnymn7 wrote:
Yes, I've been wondering how water "proof" mc4's are? I will be installing a combiner box, but I still need to extend the panel cables to the box. I imagine some tightly wound electrical tape should help. I could always re-do it, once or twice a year, to be safe. no biggie. I'll be inspecting things regularly, anyway.

Don't waist your money on MC4 for this. Butt connectors will work just fine after all it's just 12 volt and even less than that coming from one solar panel. Forget the electrical tape and use adhesive shrink tube, a kit of shrink tube can be picked up at Harbor Freight for under $9. Make sure its the Marine/adhesive as they have both kinds in a kit.

[markchengr]

MC-4 connectors are quick and easy but I wouldn't use them on an RV roof. They don't seal well enough. Use marine grade shrink tubes (the kind with melt glue inside). Heat them until the glue flows out of the ends. West Marine is a good source. I guess maybe you could put a real large one over the outside of an MC-4 but it's easier to use crimp-on butt connectors. Use a shrink tube over each wire connection and then a larger one over the whole cable joint. If you do it this way, be sure to keep track of your polarity. -Mark.

[jrnymn7]

Yes, I've been wondering how water "proof" mc4's are? I will be installing a combiner box, but I still need to extend the panel cables to the box. I imagine some tightly wound electrical tape should help. I could always re-do it, once or twice a year, to be safe. no biggie. I'll be inspecting things regularly, anyway.

[Muddydogs]

MC4 connectors are water resistant at best, I had some that didn't seal around the wire at all. In the long run if you are looking for waterproof get rid of the MC4 and go to a junction box that seals well. A little water isn't going to hurt anything in the short run and may cause some corrosion in the long run so its best to do what you can to seal out the water but don't worry over it. If nothing else use as small of a connector as you can and then seal connector with marine grade adhesive shrink tube. I replaced the faulty MC4 connectors on 2 lines of my solar panels, hooked them together and called it a day.

[CJW8]

Ton M,
Those are nice and I have used them for some applications but they are not waterproof and MC4 connectors are. All solar roof top connections should be waterproof.

[Tom_M1]

I used Anderson Powerpole SB50 connectors that I purchased from PowerWerx.com. Keep in mind that all the connectors must be the same color. For instance, a red connector will not plug into a yellow.

[jrnymn7]

Yeah, it looks like one can go with 8awg cables/connectors, but you'd want to consider what amperage you are working with, so as to not go over the connector's rating, but still reduce voltage drop.

[SkiSmuggs]

Interesting as I ordered 8awg with MC4 connectors for my install, but it was too short by a couple of feet so I went with the longer 10awg that I had, then used the 8 gauge to connect the two feet from controller to battery.

[Dakota98]

Found THIS

[ktmrfs]

all have the same mating dimensions. just get the pin/socket for the wire size you are using so the crimp is correct. I've gone down to #10 wire. Not sure if they have one for #8.

[jrnymn7]

o.k., thanks guys... I can't find much on line about them, but the consensus seems to be they are a standard size, as far as them connecting together. Just wanted to make sure before ordering.

[Muddydogs]

All MC4 connectors are the same, wire size has nothing to do with how they hook together. 10ga wire fits just fine in the MC4. Not sure if 8ga wire would fit in the connector or not.

[JiminDenver]

I would believe that the part of the MC4 that clips together is the same, the backside where the cable comes in might be different size.