MC4 problem, take a look plz...

[BradKW]

I got the big panels up on their final fit/install and thought I'd be done with it today, but came across incompatible MC4 connections...so far my Googling hasn't yielded an explanation.

The issue is that the big panels (the two little 100watt ones no problems), but the big ones have a positive (+) connector that doesn't fit into the 3-to-1 adaptor I got. But oddly enough, the negative (-) leads fit fine.

Here's the (+) connector from panel: 
[img=300x300]http://i465.photobucket.com/albums/...ads/IMG_20160814_142832_zpscxvobsba.jpg[/img]

Note the Two red O-rings. It goes in till hits rings then stops...tried removing one then both rings to see, and even without rings it bottoms out in female side before closing.

Here's the connector from the 100 watt panel which fits fine:

[img=300x300]http://i465.photobucket.com/albums/...ads/IMG_20160814_143039_zps2n2o2sfo.jpg[/img]

Hopefully there's a simple answer and I can order the correct 3-to-1 connector. Otherwise I guess I'll have to buy an MC4 crimper if I want it to work...

 

[george warner]

i believe your large panel has a HC4 connecters, and your 100w panel has MC4 connecters....

 

[BradKW]

Aha! right you are...thanks, never even heard of them before... https://www.amazon.com/Hanpearl-Hc4...71219942&sr=8-1&keywords=3+to+1+hc4+connector

 

[BradKW]

So just going to add a note here for any future peeps that hit this on a search return.

The lack of information available on difference between the two separate and not compatible plug types is kinda crazy. To make it worse, vendors don't even acknowledge there's a difference at all...many advertise that HC4 actually IS MC4... take a look at this one:   HC4-PV10C MC4 Male/Female Solar Panel Cable Connectors

Then there's another standard called H4, which actually IS compatible with MC4, but not HC4.

And I even started searching through reviews, just looking for someone to say "umm, hey, these don't fit...". Nuthin.

After an hour of Googling, here's my best theory: MC4 stands for Multiple Contact (4mm). This has a single O-ring and should be exactly what you find on any and every 12v panel. You can pick from any variety of combiner connectors, as well as a large variety of pre-made cable lengths with plugs on both ends. You can also buy a $20 crimper and fittings, making you own cable lengths.

HC4 stands for...well, not even Wiki offers a guess. Probably something like High Contact (4mm). The male/female plugs are slightly longer, probably providing improved contact. They have double O-rings, reasonably indicating a more robust seal. The HC4 came standard on my large 325 watt/ 46v grid tie panels...looking at manufacture data sheet, simple says "MC4 connectors". 

You can buy a limited selection of HC4 combiners, but nowhere are pre-made cable lengths in evidence. Same $20 crimper allows making custom cables. 

In conclusion, I'll speculate that HC4 is a somewhat better "MC4" connector than plain ol MC4, and that it's used by professional installers on larger grid tie arrays...and pros have no need for pre-made cables. Also will speculate the lack of readily searchable information on HC4 is probably explained by it being a product used by professionals who don't need it explained. 

I ordered the $20 crimpers, an assortment of doodads, and next weekend get the roof cabled without all the extra wire I was gonna have  

 

[wayne49]

Make sure you understand which gozinta goes inside the male and which goes inside the female.

It's opposite of expected if you think solely of maleness in male connector, etc.

The probe that is hollow goes inside the male connector. The non-hollow probe goes inside the female.

The probe in the female mates into the probe in the male.

Solar education.

 

[rvpopeye]

These new connectors baffle me.....there is always loss in every connector.
But I guess they are designed for the wiring challenged (better than wire nuts and cheap electric tape!).

I like to use a waterproof junction box on the roof to combine the panels and large-huge guage wire from that to the controller and from controller to battery bank.
I know Stern will probably gag on this but I use a couple of large "burndie" clamps to connect the panel and main feed wires with some large heat shrink to keep pos and neg separate,,,,,and NoAlox everywhere.

Eternabond is so permanent that I'd only use it to seal seams and other cutouts on the roof but it would work .

The clips that HDR referenced work for me too. I use them everywhere !

UV resistant wire is available and wire looms are good wire protectors though not UV safe , I just replace when they get brittle.

 

[Mobilesport]

Just curious , do solar panels come with quality wiring?   
What gage is the wire?
Sense your doing the connectors anyways would be a good time to add thick wire if
You desired it.

 

[jimindenver]

The GT panels I have had have all had 10 gauge pig tails. I found it easiest to redo all of the connectors with one batch from one seller. They don't cost much and because of it, all of my panels over the years connect as easy as the next. Even when you get two types of panel with MC4 connectors, one will be near impossible to use and the other smooth as silk.

 

[NoLimit]

UV resistant wire is available and wire looms are good wire protectors though not UV safe , I just replace when they get brittle.

I just use good ol' plasti dip on the wires for UV protection.

 

[johnny b]

Just cut em off and hard wire using quality heat shrink butt connectors and heat shrink tube.

[video=youtube]

 

[akrvbob]

You cut them off and you void your warranty. Bob

 

[rvpopeye]

I know , that baffles me even more.................