MC4 connectors

[sundug]

Can someone please tell me why all of the MC4 Wrenches I buy won't fit my MC4 connector? Thanks

 

[45North]

Mebbe they're knockoff copies, not the real McCoy?

 

[42OhmsPA]

45 seconds in

 

[PreppenWolf]

Yeah, I have some of those. They are annoying. Cut the thin outer wall off them. Then you can squeeze them with your fingers or use pliers.

The good news is you shouldn't be disconnecting them at all really. Unless you're using se portable setup, in which case order new ones if it bugs you.

 

[sundug]

I know how it's supposed to work, what I'm saying is the prongs on ALL of the wrenches I buy are too wide to fit into the connector.

 

[sundug]

I

Mebbe they're knockoff copies, not the real McCoy?

I bought several different ones, all are too wide to fit the connector

 

[sundug]

Yeah, I have some of those. They are annoying. Cut the thin outer wall off them. Then you can squeeze them with your fingers or use pliers.

The good news is you shouldn't be disconnecting them at all really. Unless you're using se portable setup, in which case order new ones if it bugs you.

Thanks, they are on my Enphase micros, and some have failed and got replaced.

 

[42OhmsPA]

My bad, now I see what you're showing in your photo. I've had a few that are tough and just squeeze the crap out of them.

 

[400bird]

There's two sizes of wrench needed for some MC4 connectors.

I lost my genuine wrenches. The replacements from Amazon are only the larger of the two sizes.

I didn't try to source the smaller release tool/wrench and just used something else to release those.

Other than trying multiple options in Amazon or eBay, you could call Renvu in San Jose, California. They sold me the original set 4 years ago.

 

[yodamota]

HAha I didn't know these had wrenches. I just carefully used a flat blade screwdriver.
I suppose if I was disconnecting tons of these connectors... a wrench would be handy.

 

[rlaggren]

There is no standard size for mc4 connectors. The different manufactures don't make their products exactly the same.

I posted some links on the problem today on this thread:

MC4 Connectors

Thanks for the link. but I don't see how tnat would do what I have in mind. I use 2 pairs of folding panels in parallel., connected to the Delta by a splitter with MC4 plugs on the Y and the solar plug connection to the Delta. That's lots of MC4 connectors to plug and unplug every time I use...

diysolarforum.com

Rufus

 

[fafrd]

There is no standard size for mc4 connectors. The different manufactures don't make their products exactly the same.

I posted some links on the problem today on this thread:

MC4 Connectors

Thanks for the link. but I don't see how tnat would do what I have in mind. I use 2 pairs of folding panels in parallel., connected to the Delta by a splitter with MC4 plugs on the Y and the solar plug connection to the Delta. That's lots of MC4 connectors to plug and unplug every time I use...

diysolarforum.com

Rufus

Just to clarify / correct? There is only one manufacturer of MC4 (MultiContact) connectors and that is Staubli, who bought MultiContact, the original inventor of the connector style).

Every ‘MC4’ you purchase from another manufacturer than Staubli or MultiCovtact (if such a thing is even possible these days) is a copycat ‘MC4-like’ connector.

Aphenol calls theirs ‘HC4’, Tyco calls theirs ‘TC4’ (or silo net Jing beginning with a ‘T’ and ending with a ‘4’).

Each variant and knock off uses slightly different mechanical dimensions and tab design and that is why each varient and knock and variant comes with its own set of wrenches (and why one knick-off’s set of wrenches are the wrong size for true MC4 connectors or another brand of knock-off).

So you’ll end up needing a set of wrenches for each variant or knock-off you use.

But the real thing to be aware of is that the UL-listing of these MC4-like variants is only valid when they are matched with identical connectors.

Staubli MC4s are only guaranteed for their current ratings when mated with another Staubli MC4 connector.

Aphenol HC4 connectors are only guaranteed for their current ratings when mated with another Aphenol HC4 connector.

My solar panels had Aphenol HC4 connectors (generally considered the closest in quality & performance to Staubli MC4s) and my Microinverters had a non-HC4 variant.

I had to disassemble my array to replace some faulty Microinverters last January after 7 years and was absolutely shocked to discover that most of my HC4-to-non-HC4 connections had melted and fused the plastic.

Most Microinverter manufacturers such as Enphase now offer variants of their Microinverters with different flavors of UL-listed connectors such as Staubli MC4, Aphenol HC4, etc or sell pigtails allowing you to safely convert from their native connector to any of the more popular UL-listed knock-offs for exactly that reason.

You should always check that any ‘MC4-like’ connector you purchase has UL listing and be aware that any time you mate two dissimilar MC4-style connectors, you have voided your UL listing as well as your warranty and you are likely to get moisture ingress and eventually suffer from corroded contacts and melted /,fused plastic the way I did.

So needing different wrenches got the different MC4-style knockoff connectors is really not the issue to be most concerned about…

 

[Crowz]

The one pictured by the op I call squeezies. Since no tool is supposed to be used on them other than maybe a pair of pliers. Squeeze the outer part and they come apart.

The 2nd type I call originals since that's what all of my older tools fit.

The 3rd type I call stupid/wtf/!$@#@$.

These require a weird looking tool that luckily came with the things that had the plugs that looks like a cross between a weird hair comb and a mc4 tool. Long prongs on them. I need to take some pics of these things and post them.

 

[rlaggren]

@fafrd +++
That pretty much nails it. Kind of a wake up to me - connectors are non-trivial. You marry your connector manufacturer and it's important to choose carefully! You can be polygamous but... That gets a bit tricky! <g>


Rufus

Just to clarify / correct? There is only one manufacturer of MC4 (MultiContact) connectors and that is Staubli, who bought MultiContact, the original inventor of the connector style).

Every ‘MC4’ you purchase from another manufacturer than Staubli or MultiCovtact (if such a thing is even possible these days) is a copycat ‘MC4-like’ connector.

Aphenol calls theirs ‘HC4’, Tyco calls theirs ‘TC4’ (or silo net Jing beginning with a ‘T’ and ending with a ‘4’).

Each variant and knock off uses slightly different mechanical dimensions and tab design and that is why each varient and knock and variant comes with its own set of wrenches (and why one knick-off’s set of wrenches are the wrong size for true MC4 connectors or another brand of knock-off).

 

[fafrd]

@fafrd +++
That pretty much nails it. Kind of a wake up to me - connectors are non-trivial. You marry your connector manufacturer and it's important to choose carefully! You can be polygamous but... That gets a bit tricky! <g>


Rufus

If you want to be as safe as possible, that means buying matching connector for your solar panels and matching connectors for your Microinverters or any other equipment that came with pre-installed connectors and making yourself some short pigtails.

If you have used solar panels with no warranty or are unconcerned about solar panel warranty, you can also just cut off he connectors on the solar panels and replace them with connectors that match your Microinverters (hopefully Staubli).

Or, if you’ve got Microinverters with pigtails using unknown / no-name Knock-off MC4-like connectors and you are not concerned about warranty, cutting those off and replacing with connectors of the same brand used on solar panels is an option (though asking your Microinverter manufacturer for matching connectors and making short pigtails might be a better way to preserve your warranty).

 

[Crowz]

Quality of the plug probably matters plus age and if debris gets in there. I'm not sure what happened on this one that I had that melted but the panel side of the cable is on a panels that is around 8 years old and has been connected and disconnected a good bit.

I'm considering replacing all of my mc4 connectors on a schedule after this happened to me.

 

[fafrd]

Quality of the plug probably matters plus age and if debris gets in there. I'm not sure what happened on this one that I had that melted but the panel side of the cable is on a panels that is around 8 years old and has been connected and disconnected a good bit.

I'm considering replacing all of my mc4 connectors on a schedule after this happened to me.

What connector brand was that on both panel and whatever it was connected to on the other side?

 

[Crowz]

Windy Nation made the cable which is what is shown in the video. The panel it was connected is was some china brand from years ago that probably doesn't exist anymore.

 

[fafrd]

Windy Nation made the cable which is what is shown in the video. The panel it was connected is was some china brand from years ago that probably doesn't exist anymore.

Did Windy Nation specify the connector brand used on that cable?

Even if the panel is no longer available, the datasheet may specify the connector type used.

For example, my Sunedison Solvantis 335W panels from 2016 are no longer available (along with the company that made them) but the datasheet specifies:

‘Connector Type: Amphenol H4’

I didn’t pay any attention to the connector brands when I assembled my array and blindly clicked them into the MC4-like connectors on my Microinverters when I assembled the array in 2016.

Last January, ~6-1/2 years later I discovered most of the connectors fused when I had to diss assemble the array.

The fused connectors all had corroded electrodes, so my guess s that moisture ingress initiated the degradation cycle.

The mismatched connectors from different brands allowed moisture to penetrate the seal within the housing.

The moisture corroded the surface of electrodes over the years.

The corroded electrodes developed contact resistance that increased heat generation though the connector during high-production hours of the day.

The increased heat generation heated up the connector plastic and eventually melted the male housing to the female housing.

The panels were still producing and electrical can next II’m between panel and Microinverter was still there, but more and more energy was being wasted by heat generation through the corroded contacts.

I’m lucky I discovered this by chance after 6-1/2 years - there are stories of peoples roofs burning down and the suspicion is that it has been caused by mismatched connector types.

In fact, there is some major lawsuit (Walmart vs Tesla?) won by the customer (Walmart?) because they had one or more major fires caused by mismatched connector types on the defendant’s (Tesla / Sunrun?) installation.

All MC4-type connectors are not the same and any connector type should only be mated with a connector of the same type (this is the basis of their UL certification and the maximum current specification).

 

[Crowz]

Did Windy Nation specify the connector brand used on that cable?

Even if the panel is no longer available, the datasheet may specify the connector type used.

For example, my Sunedison Solvantis 335W panels from 2016 are no longer available (along with the company that made them) but the datasheet specifies:

‘Connector Type: Amphenol H4’

I didn’t pay any attention to the connector brands when I assembled my array and blindly clicked them into the MC4-like connectors on my Microinverters when I assembled the array in 2016.

Last January, ~6-1/2 years later I discovered most of the connectors fused when I had to diss assemble the array.

The fused connectors all had corroded electrodes, so my guess s that moisture ingress initiated the degradation cycle.

The mismatched connectors from different brands allowed moisture to penetrate the seal within the housing.

The moisture corroded the surface of electrodes over the years.

The corroded electrodes developed contact resistance that increased heat generation though the connector during high-production hours of the day.

The increased heat generation heated up the connector plastic and eventually melted the male housing to the female housing.

The panels were still producing and electrical can next II’m between panel and Microinverter was still there, but more and more energy was being wasted by heat generation through the corroded contacts.

I’m lucky I discovered this by chance after 6-1/2 years - there are stories of peoples roofs burning down and the suspicion is that it has been caused by mismatched connector types.

In fact, there is some major lawsuit (Walmart vs Tesla?) won by the customer (Walmart?) because they had one or more major fires caused by mismatched connector types on the defendant’s (Tesla / Sunrun?) installation.

All MC4-type connectors are not the same and any connector type should only be mated with a connector of the same type (this is the basis of their UL certification and the maximum current specification).

None of the panels I have list the mc4 connector info.

This is from the chinese panel that was on the other end of the cable.



I also went and looked at my renogy info and windy nation panels I have and no mention of the mc4 manufacturer used. So I would say the connector used being on the info sheet isn't that common at least on the panels I have its not there.