Solar MC4 cable connectors

[DavidMcMullan]

Are the MC4 cable connectors for solar panels sufficiently waterproof for outside marine use? Any negative experience? Or would they be better located inside a waterproof junction box?

 

[PetiteFleur]

I cut my connectors off, went through the deck with Index deck glands and connected inside the boat with Wago connectors onward to the controller. I used the Index marine dual cable pear shaped deck glands so cables lie parallel to the deck.

 

[lustyd]

Depends on the IP rating of the connectors you have, but probably fine.

 

[CJ13]

I used MC4 connections for my Solar installation 2 years ago and no problems so far.

 

[UK-WOOZY]

MC4 connectors on both panels and no problems.

 

[stuartwineberg]

MC4s are good if you do not plan to disconnect them regularly but are locking. They can be split but it isnt convenient. They are designed for outside use on roofs etc so should be fine from that point of view. Other connectors are Andersons which can be fitted wth waterproof boots or as above take the cable through the deck. I have portable panels and need to take them on and off all the time so have fitted a Bulgin deck socket. The only snag there was the need to splice a short length of finer cable onto the solar feed as the 4mm cable on the panel was too heavy for the connections on the bulgin. The forum was very helpful so do dig back into the threads.

 

[DavidMcMullan]

Thanks for the positive feedback. I will plan on just using the MC4 connectors.

 

[Graham376]

Thanks for the positive feedback. I will plan on just using the MC4 connectors.

Just to be different, here's a negative comment. We had intermittent bad connection on one of the MC4 connectors, which were below deck so cut them off and used block connector. Personally, I prefer below deck cable joints wherever possible, wouldn't use MC4 again.

 

[yotter]

I have 2 roving panels on deck and have used MC4 connectors, I have found them prone to corrosion and unreliable, perhaps not fit for a hostile marine environment. I may just lenthen the cables and terminate below or under the sprayhood.

 

[101chugger]

MC4 connectors bought from Photonic Universe 2 seasons ago and sit on the wheelhouse roof in full sun/rain/wind. They connected with a very satisfying click and have worked effectively from Day 1.

 

[yotter]

MC4 connectors bought from Photonic Universe 2 seasons ago and sit on the wheelhouse roof in full sun/rain/wind. They connected with a very satisfying click and have worked effectively from Day 1.

Thanks for that, I got my panels from Photonic Universe , but cannot recall were I got the extra connectors, I am sure there are varying qualities. I may order some from PU and see how they get on.
Many thanks

 

[V1701]

Smearing around the joint and where the cables enter the connectors with silicone grease for a bit of extra peace of mind doesn't go amiss. I've had no problems with them on boats and on a campervan roof...

 

[yotter]

Just recall that I got my MC4 inline diodes from PU, and they were pretty corroded after a 2 years. Silicone grease is a good tip, but it was the mating copper/copper connections where the corrosion was. I am thinking of extending the cables (2 parallel panels, so 4 single cores), with sealed soldered joints then joining them in parallel under the sprayhood where they are afforded better protection (it is Scotland).

 

[Buck Turgidson]

mine are on the way out after 3 years. I'm still mulling over the replacement.

 

[Daverw]

When we fitted ours they had a good sealing ring on the actual body of the connector but the cable entry glands were poor, I loosened them, filled with sealant and retightened, been good since