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Gen 1 40A connector and NEMA 14-50
- Thread starter Matt L
- Start date
AlanSubie4Life
Efficiency Obsessed Member
AlanSubie4Life
Efficiency Obsessed Member
eprosenx
Active Member
For what it is worth, I think we here in the forums are exposed to the “exception cases” a lot more than the “normal cases”.
There are 10’s of thousands of UMC Gen 1 units in the wild that are presumably working just fine.
I am not sure I would go as far as to recommend against their use. They might have a slightly higher anomaly rate than the Gen 2 units (due to the lower amps, the improved design, and the thermal sensors), but that does not necessarily mean they are unsafe to operate. It all depends on what your risk tolerance is.
Part of me kind of wants one so I can charge at 40 amps while on the road.
AlanSubie4Life
Efficiency Obsessed Member
For what it is worth, I think we here in the forums are exposed to the “exception cases” a lot more than the “normal cases”.
There are 10’s of thousands of UMC Gen 1 units in the wild that are presumably working just fine.
I am not sure I would go as far as to recommend against their use. They might have a slightly higher anomaly rate than the Gen 2 units (due to the lower amps, the improved design, and the thermal sensors), but that does not necessarily mean they are unsafe to operate. It all depends on what your risk tolerance is.
Part of me kind of wants one so I can charge at 40 amps while on the road.
Agreed on being exposed only to the exceptions...
Yeah, I imagine when used with appropriate levels of caution it would probably be fine. Getting a full 40A would definitely be a plus...the more the better.
AlanSubie4Life
Efficiency Obsessed Member
Yeah, seems more likely that you'd want the higher charge rate on the road anyway. I guess the downside for road trip use is that (perhaps) the Gen1 is slightly less reliable due to its various (rare) failure modes. I think likely the Gen 1 is fine for home use; just use it with appropriate caution - feel the temperature of the plug, watch the voltage the car is receiving, look for changes, etc. That being said, with the various stories, I'd personally be hesitant to use one in my home, even with appropriate caution...just too much stress for me.
I use a Gen 1 and haven't had any issues. Barely gets warm.
After the stories I read here I definitely kept (and keep) an eye on it. I agree people who use one with no issues are unlikely to post about it. OTH, people with burnt pins and outlets are rightly going to start asking questions.
That said I don't travel long distances so it rarely charges for more than a few hours.
After the stories I read here I definitely kept (and keep) an eye on it. I agree people who use one with no issues are unlikely to post about it. OTH, people with burnt pins and outlets are rightly going to start asking questions.
That said I don't travel long distances so it rarely charges for more than a few hours.
P-Lo801
Member
Yikes, I just bought one of these Gen1 UMC and have been using it as my permanent EVSE at home leaving it plugged in 24/7, and decided to use the Gen2 that came with my car as my mobile unit to keep in the car; fortunately I mostly charge at work, so I only use it to charge every now and then. Should I do the opposite and go back to using my Gen2 as the permanent EVSE at home and use the Gen1 as my mobile one instead?
I wish I knew about these "horror" stories being mentioned in this thread because that would've definitely deterred me from getting it. I was wondering why they were being sold for a really good price too, compared to the Gen2 since they charge at 40a.
I wish I knew about these "horror" stories being mentioned in this thread because that would've definitely deterred me from getting it. I was wondering why they were being sold for a really good price too, compared to the Gen2 since they charge at 40a.
AlanSubie4Life
Efficiency Obsessed Member
I would swap, but really, I would just go and read about the various issues. There are different versions of the Gen 1, there are issues with 40A circuits with 14-50 outlets which really is not a UMC issue, there are issues with the plugs, there is no thermal monitoring I gather, they can have a fairly high failure rate, etc. Honestly I don’t know much about it. Many people use them without issue.
Anyway, once you understand the issues, you can figure out what makes sense for you and how many of the concerns actually apply.
I would say at a minimum that if you don’t need the charge rate, then it is probably best to dial it back - there is minimal value in a higher charge rate if you don’t need the speed; there are only modest changes in efficiency at those levels. You can always increase it on an as-needed basis, to whatever is safe for your installation.
Anyway, once you understand the issues, you can figure out what makes sense for you and how many of the concerns actually apply.
I would say at a minimum that if you don’t need the charge rate, then it is probably best to dial it back - there is minimal value in a higher charge rate if you don’t need the speed; there are only modest changes in efficiency at those levels. You can always increase it on an as-needed basis, to whatever is safe for your installation.
eprosenx
Active Member
Honestly, I think the UMC Gen 2 may be more useful when traveling due to the larger range of adapters available? (Though you can get 3rd party adapters for the Gen 1 too) I also would probably trust a Gen 2 a little more when traveling not to fail on me? (Not sure what I base that on other than age)
I really don’t think there is a massive systemic issue here with the UMC itself. Just make sure your wiring is good quality and connections are tight and not getting hot and you should be fine.
If you want to add a margin of safety, just manually set the charge rate down lower. Say 32 or 24 amps if you don’t need to charge that fast anyway.
I did not mean to scare anyone with this thread! Just be aware of the strengths and weaknesses and stay vigilant. But don’t let it control your life! We are comparing very the incidence rate of very infrequent events. And all of the ones I am aware of did not result in actually fires (just nearly could have been fires).
AlanSubie4Life
Efficiency Obsessed Member
P-Lo801
Member
I'll search around, but were they based on when the car was plugged in to the car, or just with the unit?
AlanSubie4Life
Efficiency Obsessed Member
Generally the failures of concern are when the car is drawing current from the UMC. Though potentially some of the failures could be precipitated by a charging event, but only happen to turn into a dead short when the car is unplugged (unlikely though).
Tesla Replacing Gen 1 UMC with Gen 2 UMC
New UMC 14/50 limited to 32 amps... WHY?!
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AlanSubie4Life
Efficiency Obsessed Member
Well...as much as I hate these vampire drain sources...the 1.5W difference is honestly not that big a deal.
I worked really hard to lower the always-draining power of my house when I first moved in...and ended up at 150W (I started at closer to 300W).
There is 7W from the spa equipment, 40W from the AC, 10W from the cable modem, 20W from the cable box DVR, 5W from the doorbell. And various other small sources that really add up...I have them tabulated somewhere...
Things I removed were the security system (it was 60W - I unplugged it - don't need it - replaced with camera DVR which is something like 30W - which is awful), the garage door opener (40W - I replaced it), etc. And I've gotten a more "efficient" cable box, though 20W is still frightful.
I throw the breaker on the AC for about 7 months of the year....just make sure to turn it on 24 hours before use to allow the heater to operate.
Honestly we could probably save a lot of energy in this country if we actually had rules which created disincentives for this sort of thing. The always-on sources, which provide nearly zero value, account for 15% of my annual energy use (1.3MWh). That total annual use includes the charging for an EV (about 1.7MWh for 7000 miles of driving). 150W all the time is a big deal!
But 1-2W...not going to sweat it. Start with the heavier hitters for your home vampire drains (no, I'm not talking about the Tesla here...that is a topic for another thread
). The extra 1.5W of power in the Gen 2 is possibly for the temperature monitoring added to the Gen 2.
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nwdiver
Well-Known Member
If you like your GEN 1 don't charge >20A unless you need to or you won't have your GEN 1 for long...
I dunno... I'm 2/2 on killing GEN 1 UMCs. And it's hard to tell how many of those UMCs are used regularly AND at ~40. I'm sure many of the owners have a HPWC and many more charge at a lower current or use 110v.
IMO the best advice is to pick the lowest current that gets the job done and use that unless you need more....
I would... I mean... if you're traveling would you rather charge at 32A or 40A?
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Eno Deb
Active Member
I wouldn't put too much stock into the inductive power meter readings. For example, the model you used
has an IEC/AS 62053-21 accuracy rating of 1.0, which means the measurement can deviate up to 1% of the full rated load of the meter, which is 100A in this case. Especially at low load and a power factor far away from unity the accuracy of these meters will not be good. The difference of the displayed power could easily be caused by product variations or the way the inductor is installed on the cable. I think the main takeaway here is that the idle power use is negligible.
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