Hi Jay,
The testing which was done was a third party test I think through Interek I believe, and not through UL.
The testing of the H4 (not the UTX) and the MC4 compatibility was in fact tested on 14AWG connectors only. There might be new testing out there that I haven't seen, not sure.
After that testing was done, Amphenol redesigned their connectors slightly, to achieve UL certification for a higher voltage rating. When this happened, we started seeing more MC4 to H4 failures.
Amphenol has since taken the H4 out of production and we are no longer able to source these direct. There is still a lot of stock out there, but it has to be sourced through their distribution partners.
The H4 connectors have been replaced with their UTX line, available in both machine terminals and stamped.
In regards to Walmart/Tesla our experience has been the compatibility issue does not rise from the manufacturer of the panels. The issue rises with the connector manufacturer. If there is a catastrophic failure in the connection points the module manufacturers will ultimately bring the connector manufactures to the table, which in turn will come back to the contractors builders risk.
Additionally, per "UL 6703 Standard for Connectors for Use in Photovoltaic Systems" Section 1.5 states the following:
This standard covers PV connectors whose dimensions are not defined in any national or international technical standard. Connectors are identified and tested with compatible mating part (or parts if multiple exist) and are to be of the same brand, unless multiple product manufacturers are submitting under the same evaluation for the purpose of proving intermatability.
Bryan Norkunas
br...@pv-cables.com
Jay wrote at 06:27 PM 8/25/2019:
I've seen some paperwork on something similar. It was tested with #14 wire, which of course no one uses which makes it void.
Also who is now legally responsible if there is an issue?
I heard of a big US distributor who had a similar report done. 14 gauge wire. After the fire, and all the lawyers the report/ certificate was worthless, which put the legal responsibility back on the distributor.
What I don't understand is that connectors are about the cheapest part of the install. Just use like for like and eliminate most issues and also any liability. ( see latest Walmart/ Tesla fiasco, grab some popcorn gonna be good)
I've rarely seen like for like failures but many dissimilar ones.
PV Cables has them all, even the really weird ones.
Info I've seen from MC says that different OEMS use different coatings which don't always agree and can cause accelerated corrosion. Actual sizes of the plastic and metal and tolerances can be off creating issues.
Just not worth it in my view.
My 2cents
Jay
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