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Tesla Sending New Wall-Charger Adapters After Garage Fire
JoeyRox writes "Tesla is sending its customers new home charging connectors after recent reports of chargers overheating in garages and one instance of a fire inside a wall socket that held one of the chargers. Tesla CEO Elon Musk said the new charging adapter will contain a thermal fuse capable of terminating the charging process if it gets too hot. 'These are very rare events, but occasionally the wiring isn't done right. We want people to have absolute comfort, so we're going to be providing them with an upgraded adapter.' The company also issued a software update in December to address the overheating issue."
Older houses from the mid 20th century may have aluminum wiring, which turned out to be a really bad idea. They tried it because the cost of copper was going up and the cost of aluminum was going down, but it turns out that the properties of the two metals are different and the aluminum wires performed really poorly over time.
Occasionally living proof of the Ballmer peak.
My 20A appliance loop in the kitchen has 15A receptacles because, heyyyyyyy, you're not really going to draw 20A out of these right? Those 2000 watt appliances don't go on a 20A loop that can pass 2200 watts... I use a Breville 1800W toaster oven drawing over 16A through one receptacle. One 15A receptacle on 20A wiring.
Most 15A receptacles are rated for 20A pass-through, so they should be perfectly fine to use on a 20A line. The only time you should need a 20A receptacle is if you have a single device with a 20A T-shape plug.
I was going to say, it's entirely possible the wiring in the wall was bad.
This is one possible scenario which has happened in the past. Maybe it was aluminum wiring, which has a much lower thermal expansion rate than copper. Back in the 70's it was really common for developers to use aluminum wiring in houses because it was cheaper than copper. My house had aluminum wiring. The previous owners of my house were really underhanded. They ran copper off the electrical box up in behind some insulation and connected it to the aluminum from junction hidden junction boxes, and because home inspectors don't do "destructive" inspections, meaning they don't even move insulation, we didn't find out until years after we had bought the house. We had a wall socket stop working and when I opened it up to see what was wrong I found the aluminum wire had completely detached from the terminals. Luckily my father-in-law, who doesn't live near by, is an electrician because we had to have the whole house rewired. It's still not illegal to use aluminum wiring, copper is recommended, but it's not requried. The higher temperature of the adapter could cause the aluminum wire to expand and pop off the plug terminals in the wall box, which can lead to arcing and fires.
It really wouldn't be Tesla's fault if developers were using cheap materials when building the house, but it is nice of them to do something to try and mitigate future issues after it becomes a known possibility. We can't account for every scenario that will ever occur, but we can learn as we go along.