Also last week, Business Insider reported that Tesla launched an effort to replace a faulty part used in some of its solar panel systems last year. It was unclear whether issues with the component known as a “connector†affected Walmart or Amazon installations.
Tesla said in response to the Business Insider story that some connectors manufactured by Amphenol Corp. “experienced failures and disconnections at a higher rate than our standards allow.†Over the past year, the company said, less than 1 per cent of sites with these connectors exhibited abnormal behavior.
In a statement Sunday, Amphenol rejected any suggestion that its products caused the fires.
“We have no reason to believe that Amphenol’s products are the cause of any issues related to the claims filed by Walmart against Tesla,†the Wallingford, Connecticut-based company said. “We stand behind the quality of our products.â€
Amphenol has been a major connector vendor longer than I've been alive (I have faint memories of the Kennedy-Nixon debates). They are a solid company. OTOH, pretty much any solar companies like Solar City I regard as mountebanks, slightly more slippery than non-dealer used car lots.
But, taking Tesla's word for it that the connectors "failed", how night this have happened? Well, high current connectors have to pretty much perfect contact - from the wires to the connector contacts, from the socket contact to the pin contact. Poor contact in any of those interfaces will heat up, degenerate and get hotter, and either catch fire or open up with an arc that causes a fire. The plastic materials used for connector shells are supposed to be self-extinguishing,
but the heat of the arc can keep a fire going and flaming molten plastic can cause the fire to spread.
So, what could cause poor contact at one of those interfaces? Contacts are normally crimped onto wires. I hate this, but a properly done crimp will be gas-tight and maintain a low-resistance contact for years or decades.
BUT a good crimp requires using the the manufacturer's tool, properly maintained and adjusted, the correct-sized contacts, and skillfully done. As for the contact-to-contact interface (whether pin-and-socket or hermaphroditic), that too must be near perfect. The correct contacts must be used (e.g. current rating). If the connector is exposed to weather, the proper shells must be used. Cables must be routed so there are no bends exerting force on the connection that could distort the pins or sockets.
That's a longish and somewhat technoid explanation of why I think the connectors caught fire, but probably due improper installation rather than actual defective parts.