Does anyone know if the heat related fuse in the new 14-50 adapters resets after it cools down? Or is it a one time fuse?
I don't think anyone knows, I haven't seen if any have been sawed open. Would you like to be the first to find out? Loosen a screw on your 14-50's wire and give 'er a whirl at 40A.
I think it would be safer to just point a heat gun at the adapter when charging. Or better yet, ask Tesla...
Oh wow, good thing I didn't try to test it! Just got a call from Tesla saying that a thermal fuse was an earlier concept, but in the end they ended up just using high temperature materials, better welds, and the firmware update to "solve" their issue. So, no thermal fuse at all.
Hmmm, I am not surprised. I suggested earlier that the light grey material was a different and presumably higher-temperature plastic, but was shouted down on another thread at the time. :wink:
I guess this is correct. Tesla filed an updated remedy plan with the NHTSA on February 24th: http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM454956/RCDNN-14V006-7510.pdf Too bad. It seemed like a thermal fuse would mitigate against problems with the receptacle, but this won't.
Well no, the new plastic and better welds should make sure that adapters don't melt. And then you have the firmware changes that reduce charging current. Actually, I haven't heard about an adapter melting issue for a while now...
Yeah, now I'm kind of reluctant to replace my original adapter, which has been working well, with this new one, which has significantly more play in the UMC-to-adapter connection. I hope that Tesla will provide some testing data to show that the new adapter is really better.
Hmmm, I hope you are right about this but my instincts say that, over time, wear will cause heating. Perhaps the new plastic will withstand higher temps but there are limits. I really liked the idea of a fuse as that would be far safer.
I know that there are many others who dislike this idea, but I think the car's greater intelligence about the charging conditions is what's going to make the biggest difference here. Hotter plastics are good, but the car automatically backing down the current will play a big part in ensuring the cords don't melt.
According to what Tesla told the regulator in a letter, they tested both the fused adapter and the one without a fuse and found that the fused one didn't help at all.
That's because there isn't much they can do to improve the adapter. The problem is also in the UMC end. Cutting off the adapter and using a male 14-50 plug eliminates most of the problems. I'm guessing that Tesla doesn't want to take on the expense of replacing the UMC with a new design due to cost, which is fine except for the fact that they are still using the crappy design. If something sucks, the last thing that should be done is make more of it.
There are only some limited options, and the issue seems confined to the 50A adapters; throwing the entire design out is throwing the baby out with the bath water. Cutting off the adapter also makes the UMC impossible to use with 6-50's, 14-30's, 5-15's, 5-20's, among the other options we have. I think Tesla should have switched to something like a UMC2 with bigger pin surface area that would be subject to less heat once the issues were determined. We saw early clues that the design was bad, and if they had made a design decision then, far less people would have been affected. That said, I would still take this design over the one-cord-for-each-outlet design, or a pure J1772 design. (For what it's worth, the car end of my HPWC is beginning to get hot to the touch again while charging @ 80A. The cord's been replaced once for the same issue. Wonder if we're going to need a contact cleaning kit, or if the valets/porters will be sent to clean/inspect the contacts for those customers who have them.)
I agree that there is some benefit to intelligent charge monitoring but I remain skeptical that sw can detect a problem with 100% accuracy. I'd love to hear the theory behind what they are doing though won't hold my breath.
Yes, compared to the blade sizes for the 14-50, the Tesla pins look minute. Are these tiny pin connections subject to any NEC requirements? Wonder what UL would say if they had to certify? Even the J1772 pins seem too small to me, although I suppose there is more surface area than meets the eye due to the male/female mating surfaces.