Water ingress; MC4s or diode/jct box?

[12VoltInstalls]

I previously posted a mention regarding this https://diysolarforum.com/threads/water-in-diode-box.27888/

I wasn’t sure the diode boxes were leaking but it appeared that way. No matter; damage was done.

The other morning (in the course of re-proving to myself that I more amps are available for charging under poor or early light with series panels over parallel) I discovered a third!! panel with water in the junction box. grrr
(BTW WindyNation has been great)
Not only that but lots of water was inside several of my MC4 connectors- again. Complete with rust/corrosion.

I fixed it all but it appears that it is posdible that the MC4 orings are leaking, and re-closed the junction boxes with lexel (bad idea long term!!) as they could be leaking. Or not?

Checking everything with extended scrutiny I suspect that I may have found the culprit: the compression seals over the panel and cable wires among various brands is essentially not tight on the insulation sheathing. Hmmm. Which leaves the ponderous conclusion that water is getting into the wires from the MC4 connectors and migrating several feet into the diode boxes!!?! though the orings themselves are not leaking.

FWIW it appears that the oem WindyNation panels do not leak at the wires but I can’t rule that out. It appears that Bouge RV MC4 stuff mates fine to WindyNation MC4 stuff. It also appears that of the various other three or four “brands” of MC4s I’ve used either break or leak because they do not seal to the cable sheathing adequately.

At this point I think most or all of the windynation, none of the Rich Solar, and all of the other “brands” of MC4 have been replaced with Bouge RV MC4s. Bouge, once tightened, will not let me twist or wiggle the cable in the fittings.

This is driving me mad!

Has anyone else seen this problem-water in the wires? After I cut off an MC4 I can whip the wire against the building and get almost a half-teaspoon of red/brown water droplets out of it.

@chrisski mentions confidence even in under water situations (not happening here!) so I’m perplexed. Where is the water coming from? Why? Are my observations of moveable wires in fully tightened compression nuts accurate?

I’m not used to having problems with my installs ever. No redo’s in boats, utility trailers, or offroad vehicles. So to have this issue with idiot-proof connectors is exceedingly annoying to me.

I use Anderson Pole and MC4 to connect portable panels. On the RVs portable panels where it could get wet or be submerged, I use MC4s….%snipped… For that type of waterproof, I'd like an MC4 connector. If not MC4, something with an IP rating. Basically means it can be submerged in a few inches of water without leaking. Not sure Powerpoles meet that criteria.

 

[chrisski]

I think you may be a victim of some cheap counterfeit,or at least poorly manufactured MC4s. One or two perhaps could be user error, but not multiple.

My MC4s are located in the desert and gets the occasional downpour, and I have not had problems with them yet

I bought some MC4 Y adapters from Renogy, and those just looked quality compared to my Bulk MC4 connectors I attach to them. The cheaper, bulk purchase of regular MC4 connectors were made of thinner metal, not as stout. With the Renogy, the male pin was nice and solid, the Bulk purchase was hollow.

A step up may be Amphenol H4 connectors, but I have no experience with those. Both the H4 and MC4 are UL listed, but not when used together (mating a H4 to MC4) even though it fits just fine.

What I am curious about is the state of the ring on your connectors I have circled in green:


I sometimes have issues with the O-Ring attached to that piece. I did not see that in any of the pictures.

 

[12VoltInstalls]

One or two perhaps could be user error, but not multiple.

I thought the same thing. I’m pretty adept, deft, and quality conscious / conscientious but I’m human.

But I’ve had issues with these things for months and I’ve decided (concluded?) that some MC4 fittings leaked water at the compression sleeve and - as unlikely as I am to believe it- migrated inside the wires to the other fittings and eventually the diode junction boxes.
(FWIW the Bouge MC4s seal nicely and haven’t broken)

I’ll see if I have one of the fittings around still and shoot it later

 

[Bud Martin]

May I ask how you manage to remove the terminals from the MC4 bodies? Once the terminals are locked in place I cannot remove them, I have yet to find the way to remove them yet without destroying the connector.

 

[toms]

I have seen hundreds of MC4 terminals cause the same issue you are seeing. (I’ve picked up a lot of panels that have been taken out of service because of it)

In Australia it is written into the wiring standards that MC4 connectors must be from the same manufacturer.

I only use 2nd hand panels myself, and always remove the MC4 connectors and replace with a splice crimp wrapped in adhesive heatshrink.

MC4 connectors are literally the most inexpensive connector that is fit for purpose.

 

[12VoltInstalls]

Australia it is written into the wiring standards that MC4 connectors must be from the same manufacturer.

That’s what I have concluded is necessary

Butt crimps would make my little experiments with different configs of panels rather…ponderous. The MC4s were fine until the WindyNation 20’ cables had one break over the winter. Ice buildup and some wind…
I discovered it, ordered fittings, and fixed not long after. But whatever make believe chinese brand name of the day fittings I bought broke quickly and I replaced with another brand with a slightly different design. I just hadn’t noticed the compression sleeve wasn’t tightening around the cable and I think that’s when the water started running in willy nilly

how you manage to remove the terminals from the MC4 bodies? Once the terminals are locked in place I cannot remove them, I have yet to find the way to remove them yet without destroying the connector.

Funny you should ask. I’ve been using two tools: an ulna and a radius, along with a pair of biceps to rip them apart. If you pull straight out, the barbs on the ferrule will exit the MC4 body. Unless you’re creative in opening crimps they are not re-usable anyway.
And there is a release tool for virtually every click-assemble-inserty thingie on the planet but I don’t own one for MC4. Not recommending the ones pictured per se, just a pic of some. The best ones are tubular but MC4s have a step so those won’t work until cut off at the rear. (2nd pic)

Or did you mean releasing the clips on the finished fittings to unplug them?
I usually pinch them with my fingers but the Bouge MC4s are hard to open- there’s plastic wrenches (pic) that open them.

The Bouge RV crimper kit is $30, comes with two cute little wenches, and six pairs of MC4s. Good deal.

 

[Tecnodave]

@12VoltInstalls

Can you provide an Amazon link to the removal tools pictured in the right photo, Something that I have fiddled with.

Never mind...searched and found them...



I have had several MC-4 connectors leak and have had water ingress several times. There are better quality MC-4 connecters and ones that are not so good.

I use Silicon Grease on my connectors to enhance watertightness and tuck my cables into the frame of the panels and tied down with zip ties to keep them out of the weather. Im real close to the Pacific Ocean so I get salt enhanced moisture to further complicate the problem.

 

[chrisski]

I'm beginning to suspect that an IP 67 is the manufacturer submerging the thing for 90 minutes with no "Ingress of water in harmful quantity." So, buyer beware, CAVEAT EMPTOR.

From Wikipaedia: https://en.wikipedia.org/wiki/IP_Code

Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 meter (3 ft 3 in) of submersion).

Test duration: 30 minutes.[3] Tested with the lowest point of the enclosure 1,000 mm (39 in) below the surface of the water, or the highest point 150 mm (5.9 in) below the surface, whichever is deeper.

 

[Just John]

View attachment 72237I previously posted a mention regarding this https://diysolarforum.com/threads/water-in-diode-box.27888/

I wasn’t sure the diode boxes were leaking but it appeared that way. No matter; damage was done.

The other morning (in the course of re-proving to myself that I more amps are available for charging under poor or early light with series panels over parallel) I discovered a third!! panel with water in the junction box. grrr
(BTW WindyNation has been great)
Not only that but lots of water was inside several of my MC4 connectors- again. Complete with rust/corrosion.

I fixed it all but it appears that it is posdible that the MC4 orings are leaking, and re-closed the junction boxes with lexel (bad idea long term!!) as they could be leaking. Or not?

Checking everything with extended scrutiny I suspect that I may have found the culprit: the compression seals over the panel and cable wires among various brands is essentially not tight on the insulation sheathing. Hmmm. Which leaves the ponderous conclusion that water is getting into the wires from the MC4 connectors and migrating several feet into the diode boxes!!?! though the orings themselves are not leaking.

FWIW it appears that the oem WindyNation panels do not leak at the wires but I can’t rule that out. It appears that Bouge RV MC4 stuff mates fine to WindyNation MC4 stuff. It also appears that of the various other three or four “brands” of MC4s I’ve used either break or leak because they do not seal to the cable sheathing adequately.

At this point I think most or all of the windynation, none of the Rich Solar, and all of the other “brands” of MC4 have been replaced with Bouge RV MC4s. Bouge, once tightened, will not let me twist or wiggle the cable in the fittings.

This is driving me mad!

Has anyone else seen this problem-water in the wires? After I cut off an MC4 I can whip the wire against the building and get almost a half-teaspoon of red/brown water droplets out of it.

@chrisski mentions confidence even in under water situations (not happening here!) so I’m perplexed. Where is the water coming from? Why? Are my observations of moveable wires in fully tightened compression nuts accurate?

I’m not used to having problems with my installs ever. No redo’s in boats, utility trailers, or offroad vehicles. So to have this issue with idiot-proof connectors is exceedingly annoying to me.

Be sure that you purchase the correct wire and connector. A connector designed for 10 gauge wire won't seal if you use 12 gauge wire. Make sure the wire is photovoltaic rated.

 

[12VoltInstalls]

Be sure that you purchase the correct wire and connector. A connector designed for 10 gauge wire won't seal if you use 12 gauge wire. Make sure the wire is photovoltaic rated.

Thanks. I have 8ga solar wire. Bouge RV confirmed compatibility

 

[Just John]

Thanks. I have 8ga solar wire. Bouge RV confirmed compatibility

8 gauge solar wire and especially 8 gauge mc-4 connectors are pretty rare. I purchased an 8 gauge solar cable from them as well, but at the time they didn't carry the connectors, just the pre-made cable.

Sorry, just checked, I got mine from Windy Nation.

Amazon.com

I have purchased 10 gauge mc-4 connectors from Bouge RV.

Amazon.com

 

[12VoltInstalls]

Amazon has WindyNation 8ga solar cables premade (and a few others but windy has the 8ga and they state copper).
I overcabled a lot I know but my OCD approved
Bouge answered many questions re: 8ga with their connectors in their listing and said 8ga is fine but 30A is still max rating for the connectors. I think the highest I’ve ever seen is 12.x amps? but I don’t recall exactly.

I can confirm they fit 8ga solar wire. Seal compression sleeve/collar isn’t tight but it’s just about interference fit on the 8ga solar wire.

I’m nowhere near overloading them. I get 54-62V 3S2P with hundred watt panels.

 

[Just John]

Amazon has WindyNation 8ga solar cables premade (and a few others but windy has the 8ga and they state copper).
I overcabled a lot I know but my OCD approved
Bouge answered many questions re: 8ga with their connectors in their listing and said 8ga is fine but 30A is still max rating for the connectors. I think the highest I’ve ever seen is 12.x amps? but I don’t recall exactly.

I can confirm they fit 8ga solar wire. Seal compression sleeve/collar isn’t tight but it’s just about interference fit on the 8ga solar wire.

I’m nowhere near overloading them. I get 54-62V 3S2P with hundred watt panels.

I'm not saying you are overloading or anything, I'm saying there is a big difference in the diameter of 8 gauge, 10 gauge, and 12 gauge wire.
If you want a water tight seal, that makes a BIG difference, and 8 gauge connectors are rare, I know because I've searched for them.

Bouge MC4

The Bouge RV MC4 crimpers with six pairs of connectors for 8ga got used today. The gusting 40mph winds at my elevation blew the 8ga solar wires around enough to snap an MC4 electrical female which apparently caused some resistance. I assume. The sun has peeked out after days of overcast this...

diysolarforum.com

I have the same set, they are not 8 gauge connectors.

 

[12VoltInstalls]

have the same set, they are not 8 gauge connectors.

They slip-fit on the solar wires and seal fine.
Bouge says they are good for 8 gauge.
And none appear to leak water.

I don’t see any issues. Are you saying I shouldn’t use them?

 

[Just John]

They slip-fit on the solar wires and seal fine.
Bouge says they are good for 8 gauge.
And none appear to leak water.

I don’t see any issues. Are you saying I shouldn’t use them?

No, but it certainly looks like you have a water ingress problem. I live in the desert and have not had the problem using the same connectors on 10 gauge wire, but this is the desert. You might try either a different connector or different cable, something is not sealing properly. They do make 8 gauge 45 amp MC-4 "compatible" connectors, but they are special order, very difficult to find, and more than twice the price. That's why I ordered pre-made cables.

 

[12VoltInstalls]

looks like you have a water ingress problem. —%— You might try either a different connector or different cable, something is not sealing properly.

The Bouge are the different connectors.

The initial problem was some broken MC4s after last winter. I bought (cheap) MC4s to replace the broken fittings.
The problem revealed itself when earlier this summer my charge rate and volts flatlined for my ‘East’ string. Wound up beating myself silly replacing MC4s and testing with my multimeter (I had full VOC with meter but charge controller was showing either low volts or NO voltage) I opened a junction/diode box and found it full of water and corrosion. Second panel- same. MC4s had water. Third panel no water, but that was a recent addition.

At this point I:
1) concluded that the compression seals in the cheap MC4 connectors were leaking
2) suspect oem solar panel diode box compression seals might be leaking
3) applied all the diode box’s covers and compression fittings with lexel (painted myself in a corner)
4) replaced virtually every MC4 with the Bouge RV MC4s

That should pretty much fix it. And seems to have.

In the course of repairing that string I discovered that half of the cables into the MC4s could be twisted in the rubber compression ferrule/sleeves. However, the Bouge RV MC4s all firmly seize into the fittings when installed. I feel much better about that.

At this point I am starting to believe the wires full of water and the water in the diode boxes ingressed through the loose cable seals. May have even travelled within the cables as weird as that sounds.

I’m not saying Bouge is the best stuff made but none have broken and my inspection yesterday shows no water in them after a few weeks of snow, rain, and strong winds. They get my approval.

Today I’m zip tieing all the cables so they don’t flail around in the not so infrequent high winds we get up here at this elevation.

 

[Just John]

I would suspect that the cables make a fine conduit for water to leak everywhere. They shouldn't, but it happens.
I can't really recommend a better brand of MC-4, I'm using either what came on the cables or the same brand you are.
I know an Italian company makes some good ones for 8 gauge cable, but I haven't ordered any to test (they are quite pricey and require a different crimp tool). The crimp tool is the biggest cost for them, and they are "MC-4 compatible", since they are rated for 45 amps, the spec for MC-4 is 35 amps.

 

[12VoltInstalls]

can't really recommend a better brand of MC-4, I'm using either what came on the cables or the same brand you are.

I wonder what it would cost to get The China People (or Vietnam, wherever) to do a run of MC4s identical to the standard that’s supposed to be in a FRP version.
Not carbon fiber obviously LOL
Like is 10,000 enough to order an affordable run?

 

[boondox]

@12VoltInstalls

Can you provide an Amazon link to the removal tools pictured in the right photo, Something that I have fiddled with.

Never mind...searched and found them...



I have had several MC-4 connectors leak and have had water ingress several times. There are better quality MC-4 connecters and ones that are not so good.

I use Silicon Grease on my connectors to enhance watertightness and tuck my cables into the frame of the panels and tied down with zip ties to keep them out of the weather. Im real close to the Pacific Ocean so I get salt enhanced moisture to further complicate the problem.

Same here. I use a tiny bit around the o ring. Never had a problem. I grease all o-rings so that they don't roll off. Not saying that was your problem but I think it is a good idea.