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MC4 scam buster - what you have all been waiting for

Boron said:
you see, plain English just doesnt work . There is only one Staubli MC4 all else are counterfeit copies.

The originals (and Mil spec multipin connectors) are made to very close mechanical tolerances and rigorous inspection during manufacture (I have visited such a factory). Cheap Charlie copies cant possibly approach that level of quality control so you can expect a substantially reduced reliability MTBF.

Note also, that this type may work indefinitely at say 5A but put 50A through and its reliability is quite different.
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Molex, Phoenix Contact , Betterie, TE connectivity and I'm sure many more are all EU/US manufacturers of MC4 connectors.

Enough with your Dunning Kruger effected brain try do some actual research instead of trying to reinvent the wheel.
 
Hedges said:
Here's a completely reliable connection that lets the wires carry all the current, isn't part of the circuit:

View attachment 230525

Now you just need a boot to slip the wires into before tightening, and a way to pump grease into it.

is that the type used for overhead power lines ? (which are copper clad aluminium with steel core IIRC.
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Hedges said:
I should have suggested this rather than a hydraulic oil coupler. Now a 3/16" copper oil pipe has a csa of ca 10mm2 (ca 7ga) good for 100A+, thread through some UV plastic tube or why bother. Good for mountain OG preppers? 5kW 48V panels (8, 4x2?). Varmint and bear proof, can be buried, makes you hot? Gotta love the KISS principle
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Could flatten it - oh looks like a copper busbar - anyone heard of tubular copper busbars?
 
Boron said:
Could flatten it - oh looks like a copper busbar - anyone heard of tubular copper busbars?
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That's not what I said (in your reference to my post)

I think you typed your words into the quote box.
 
cs1234 said:
Requiring an entire installation to have it's brand new connectors be cut off and replaced, or purchasing equipment from only one vendor because of a proprietary connector from one manufacturer is stupid.

We can't have only one company, Staubli, be the only acceptable manufacturer of an industry standard connector for solar panel installations. If the standard doesn't have some type of testing standards for interoperability between manufacturers, it's a crap standard and shouldn't have been adopted.

If there is a standard, with interoperability and testing requirements for something labeled an MC4 connector, and it's just being ignored by cheap Chinese manufacturers, that's a different story and they shouldn't be allowed to sell their product in the USA. Companies importing and selling them should be penalized.
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Indeed a very important point. I forgot to mention.

You most certainly cannot interchange MC4 pattern connector from different sources (or maybe even batches)
This has often been said on this board.

IIRC MIL std multipin connectors have a standard, with interoperability and testing requirements. And a very high cost to match.
 
Texas-Mark said:
I have some (different brand) that are going on 20 years without issue <shrug>



<yawn>
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I personally think it's a good thing when a patent runs out this really opens up the market to further improve on a time tested product.

That being said the original manufacturer does not always make the best product.
 
You really want a connector you can easily get apart. This is the primary MC4 issue. The secondary issue is the contacts are stamped foil.

The contacts should be a multi-wiping spade or solid pin, probably beryllium copper maybe plated. The connector housing should be a threaded barrel. MC4 was a way to make a custom $0.05 cost part and sell it for $5.00. So I have a connector that costs a nickle running my panel that costs $150. Just effing stupid. You could make something decent for $0.25 and still charge $5.
 
Four 9's and 50 connections per installation, does that mean only one out of every 200 houses catches fire?
 
Hedges said:
Four 9's and 50 connections per installation, does that mean only one out of every 200 houses catches fire?
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It doesn't seem that the powers that be are ok with those odds judging from the rules on solar installations. :unsure:
 
Texas-Mark said:
And yet they work 99.99% of the time. That's all that matters.
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Hmmm, there is 'working' and there is 'working well'. They work just fine until you want to take them apart, and they've been in the Arizona heat and cold and dust for a few months. And 'Four-nines' is not that great, and frankly I don't think they are quite that good. Basically they shoved a molex pin and socket in a housing, and slapped it together. Lord knows I've never had any problems with a molex connector (Computer 4-pin 12,5,2xgnd), in an environment much less stressful than laying outside in the elements, plugged into a graphics card pulling 10A or so.

The problem with a foil (hollow) pin is it can get distorted, or mildly corroded, and shoving a distorted pin in a foil socket which can also get distorted on it's own creates a lot of potential issues. This is seriously compounded as the current goes up. I'd really want to keep the current under 10 amps on these things. I'd love to see testing data pushing 20A across those connections with minor distortions. I'd bet it gets REALLY hot.

I will stand by my statement that MC4 is a seriously inferior assembly, and should be re-engineered. Things are never a problem when everything is perfect. The trick is to still be reliable when it's not.
 
ksmithaz1 said:
Hmmm, there is 'working' and there is 'working well'. They work just fine until you want to take them apart, and they've been in the Arizona heat and cold and dust for a few months.
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Funny, I have taken some apart that have been in the Texas heat for years without issue. And if I could not get one apart, I would simply cut it off. Not a big deal.
 
Texas-Mark said:
How often has a failed MC4 connector actually start a fire? One in a 10 million connectors??? How many fires are started from other failures?
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I don't really care as much about the fire angle (poorly engineered electrical appliances 'go poof' all the time) as the general reliability and usability angle. The idea behind a connector is that you can actually disconnect it quickly and easily. I've found this to be the biggest fail. I don't move my toaster oven very often, but I'll be darned if I want to replace the plug and socket if I decide to relocate or replace it. Same would go for my Clothes Dryer, and I've seen a dryer socket get hot enough to melt the cord, that would be a big fat NEMA 6-30 pulling around Oh, I dunno ~22A. . . And you want to pull a continuous 15A across those tiny little foil wrapped pins?

It doesn't have to start fires for me to think it's not a very well engineered connector.
 
Texas-Mark said:
Funny, I have taken some apart that have been in the Texas heat for years without issue. And if I could not get one apart, I would simply cut it off. Not a big deal.
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You might be stunned to know how ludicrous I think this statement is. I think being forced to cut off a "connector" because it will not come apart is the epitome of an abjectly poor design. If cutting the wire is OK, just skip the MC4 and use a butt splice.
 
Thank you Mod @HRTKD it gets very childish at times. My OP was addressing a serious topic.

After my near death experience I must close out the OP with Mk l.5, without a HS cover

The improvements are
a)original short M3 steel grub screw replaced with a SS version 6mm long with a cone point. This is very effective as it compresses the ferrule into the hole below. There is no way that cable core is going to loosen with a mechanical constraint like that IMHO

b) note the use of the readily available multifaced crimp sized to suit 10AWG. Thats very neat IMHO

I think the whole assy cost <$2 Recommend either an adhesive HS sleeve, or a 2" length of transparent PE tubing 10mm ID up to you.

Notice its all agricultural you might say. ie no fine tolerances to keep up. Plug it with grease, come back in 20 years. genuine TUV solar cables have that life and can also run at much higher temps 90C vs 60C (pvc). I think the HS is still ok but a PE tube is better and easier to handle. Basic simplicity and not worth faking it.

If anyone wants to try them out and replace MC4s (you need an unlocking tool btw to disconnect) also not to be disconnected live as the flash will burn the receptacle (though I think there is a mickey mouse no flash version IIRC. I will put some on Ebay (UK) at cost, or just get the parts off Alix. Its not rocket science - which is the whole point.
 

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Why not just use the internals from good quality terminal blocks then?

Your diy version is not tested for any of the relevant standard (EN 60998-1, EN 60998-2-1, UL1059,UL 486, CSA C22.2 No. 158-10) and it may or may not loosen over time and heat cycles.
Been in actual lab that does for exampl lots of EN 50393 test for connectors and the tests are not as trivial as it may seem.

If caught the DIY version won't pass any sort of inspection and insurance companies are happy to wash their hands if your house burns down or floods for any reason.
 
Boron said:
You most certainly cannot interchange MC4 pattern connector from different sources (or maybe even batches)
This has often been said on this board.
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Compatability of connectors - lets start with this:
We need both halves of each MC-4 connector to be compatable.
We buy PV panels that come with one half of the connection already present, some of these will plug into another adjacent PV panel ensuring compatability, and some will plug into wiring we are making using PV wire and sourced MC-4 parts.
So to make the wire connections compatable we need to match the manufacturer of the PV panels MC-4's - yet I have no idea if the PV panels use authentic Staubli connection parts or similar parts made by others, or if the PV panels even state such information.
So how do we know the compatability of the connection to the PV panels? Cut them all off the PV panels and use a single source of connector parts, to ensure they must be all compatable?
 
OffGridForGood said:
So how do we know the compatability of the connection to the PV panels? Cut them all off the PV panels and use a single source of connector parts, to ensure they must be all compatable?
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Use the damaged sacrificial panels we always have to order because of our wonderful shipping companies as a source for compatible MC4 connectors. Rip the wires off the damaged ones and run them into a junction box where you can safely convert them to non MC4 connectors for the homerun. 🤣
 
The answer is of course - Standards
When you buy a new kitchen appliance, do you cut off the plug "because it may not be compatible with your wall outlet" - no, we rely upon standards to ensure they are compatible, no matter what part of the world your kettle is from, and where you live.
 
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