What has been your experience with 10-15 year old MC connectors that have not been disconnected since installation? I'm wondering how easy they are to disconnect, do the seals harden over time, and if reconnected do they still have a good seal? How well will an old MC connector mate with a new one? I have not had the chance to break into any old connectors.
Looking for experience with 10 - 15 year old MC connectors
- Thread starter pv_n00b
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
Do you mean something other than connectors for MC cable (which don't have seals)?
kwired
Electron manager
- Location
- NE Nebraska
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- EC
I'm with Larry here. When you say MC connector most of us are thinking of this
or maybe this
or maybe this
wwhitney
Senior Member
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- Berkeley, CA
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- Retired
This is the PV forum. The OP is referring to a type of connector found on the leads on PV panels. Nothing to do with Metal Clad cable.
Cheers, Wayne
Cheers, Wayne
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Ah. I have my shortcut go straight to New Posts, so I don't notice which topic the thread is under.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Basically same here, I seldom know which forum topic is involved when just reading through new posts.
jaggedben
Senior Member
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- Northern California
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- Solar and Energy Storage Installer
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
Likewise I go straight to New Posts. But the forum is listed under each thread on the New Post page. And it's also listed just above the thread title on each thread page, which for new threads should still be visible when you click through to the thread. (Edit: at least for the desktop interface. I didn't check the mobile version of the pages may differ.)
So it's not hard to check the forum when looking at a new thread.
Cheers, Wayne
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
I can probably only speak to up to 10 years, but here goes...
My experience was mostly with micro-inverters, but also some string systems and optimizers.
Sometimes moderately difficult, even with the right tool, but I never had to give up on one.
Yes, a bit, I guess? But the ones I've seen were still serviceable. Some seals are pretty stiff when new, too.
I think so?
I think it will do fine. It might be moderately more difficult to plug an old positive plug into a new negative plug than vice versa. Because the seal is on the positive plug, and if the seal has hardened ...
My experience was mostly with micro-inverters, but also some string systems and optimizers.
Carultch
Senior Member
- Location
- Massachusetts
MC in the PV context, usually means Multicontact, the brand name. As in MC4 connectors for PV array field connections.
The MC you have pictured above, is MC as in metal clad cable.
I'm running into more repowering projects where the PV arrays might be around 15 years old. Usually, it's just swapping out inverters but sometimes it involves disconnecting the module connectors so I'm wondering if people have seen issues with the older connectors and if opening and reconnecting them is creating problems.
PV industry jargon is pretty specific. So I understand the confusion.
Carultch
Senior Member
- Location
- Massachusetts
You might be looking at the old MC3 connectors, instead of the current industry norm of MC4 connectors.
The old MC3 connectors had ribbed rubber housings, instead of plastic plug-in shells. MC4 connectors require a brand-specific tool to take them apart, while MC3's could just be pulled apart directly.
No issues yet. I work on several legacy systems.
They get a little tough perhaps (?) to unplug.
One lesson learned:
If you pull and pull and the MC conn.s won't unplug ......even though you have the disconnect tool too..... and it won't separate:
the male and female connectors have fused internally due to arcing.
This was likely due to poor crimping and field installation of the MC connector on the wire.
With enough force, the MC conn.s will rip apart in an unexpected way, with the plastic housing breaking off and potentially live metal contacts sliding out and becoming exposed.
Second lesson: some installers sucked so bad, when you lift a panel the PV wire just slides right out of the MC connector. It was likely not crimped fully. Happened yesterday.
They get a little tough perhaps (?) to unplug.
One lesson learned:
If you pull and pull and the MC conn.s won't unplug ......even though you have the disconnect tool too..... and it won't separate:
the male and female connectors have fused internally due to arcing.
This was likely due to poor crimping and field installation of the MC connector on the wire.
With enough force, the MC conn.s will rip apart in an unexpected way, with the plastic housing breaking off and potentially live metal contacts sliding out and becoming exposed.
Second lesson: some installers sucked so bad, when you lift a panel the PV wire just slides right out of the MC connector. It was likely not crimped fully. Happened yesterday.
I'll sometimes have a bear of a time pulling apart mismatched PV connectors (H4+MC4, for instance), but I don't typically have issues pulling connectors apart based on age. They're pretty frickin tough, in my experience. Of course if there's installation errors, that'll be a problem. Even the old MC3s typically open and shut just fine after 2 decades of use.