We will know more with time for sure, but I figure things like this at the very least get us all to consider improving practices altogether. there is risk of electrical and or gas fire in a garage and fire is a risk just about anywhere in one's house. You don't have to be paranoid about that risk, you just need to mitigate it. giving the risks some thought after buying our first EV, I putt in a smoke detector in my garage... not because I was more at risk but because there should have been one there all along! Anything high energy, especially a gas car but certainly also an electric car, creates increased risk of fire. catching a fire early is key to reacting adequately. I recommend taking codes seriously when wiring, even instruct your electrician to go a little bit beyond code/standard with respect to gauge of wire (like down one gauge) for EVES's or for any circuit that will carry a continuous load for many hours at a time... our 80A charger is fed with 2 gauge wire, most would say that's overkill, but after seeing some goofy things like our blink charger wiring heat up because it was specked for nothing more than the 2011/12 Leaf, even though the charging station would attempt to draw up to 40A at 240V if I plugged in the Tesla S. It's crazy that anyone would wire a plug for a specific appliance rather than the max rating of that plug, but it happens! The older I get, the less I try and cut corners with stuff like this. I even had an extra heavy duty breaker box installed when the solar was put in, in advance of the Tesla S, knowing a lot of juice would be flowing through that thing over the years. And after reading about someone smoking their main line here on TMC a while back, I even asked the utility company to make sure the main line on the house was indeed substantial enough for high continuous load. Of course none of this is going to help crappy workmanship, so choose your electrician wisely!
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this is the reason why when i got my NEMA 14-50 installed i got
MAIN box > 100A Breaker > Garage box= 125A Wire #1/0
Garage Box > 50A Breaker > NEMA 14-50 = 60A Wire #6
no matter how much im pulling, the wire will take way more than the breaker or internal fuses of the UMC.
MAIN box > 100A Breaker > Garage box= 125A Wire #1/0
Garage Box > 50A Breaker > NEMA 14-50 = 60A Wire #6
no matter how much im pulling, the wire will take way more than the breaker or internal fuses of the UMC.
I start to enjoy my 3 phase installation even more. Model S charges at 11kW, adding 33 miles per hour, while the current is 16A. And yes, while 230V neutral-to-phase is more hazardous than 240V split phase, the issue here is not electric shock but fire from high currents.
My electrician advised me to re-torque the connections periodically. Temperature swings from running at nominal load tend to loosen up mechanical connections.
One of the reasons I went with the HPWC was the simpler chain between breaker and car. Even if I needed less charging capacity, I'd probably look at some hardwired option like a Clipper Creek EVSE.
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Even if you only need 40A of charging at home, I would still opt for the HPWC for home charging simply so that you don't have to deal with the J1772 adapter on a daily basis.
Agreed, the Model S plug really is much more quick and convenient. Takes me 3 seconds to plug in - I've timed it. With the J plug it takes you longer than that just to open the charge port from the touch screen.
A lot of houses, frankly, have bad wiring.
There could be a warning distributed with the HPWC: "Verify that your house wiring and breaker box are up to code when installing this. This is a high-amperage device and hidden defects in your house wiring may be revealed, which could cause fires."
There could be a warning distributed with the HPWC: "Verify that your house wiring and breaker box are up to code when installing this. This is a high-amperage device and hidden defects in your house wiring may be revealed, which could cause fires."
Al Sherman
It's about THIS car.
When I told my electrician what I wanted to do (a year ago) he came out and looked around and said that the transformer for the house was ALREADY undersized and that he wouldn't even consider my request until the transformer was upgraded. We eventually got the new transformer, a new service, and a new (Tesla) dedicated box in the garage with huge wires (cables) running to the garage. I'm obviously not saying that my situation is normal since I added two 14-50's and an HPWC but my house clearly wasn't up to snuff. A 40 amp circuit or anything up to and including my situation could be two much for any given current setup.
Uh yeah, you installed 200A worth of new circuits (2 50A circuits for the 14-50s and and a 100A circuit for the HPWC) just for car charging - if all 3 were in use at the same time, that's probably like 5-6 houses worth of demand so the infrastructure has to be beefed up to handle that.
A single 50A circuit is much more typical and not an issue on newer houses with existing 200A utility service. Might still be OK on a house with 150A service, but not likely on a house with 100A service.
Al Sherman
It's about THIS car.
Uh yeah, that's why I made it clear that my situation wasn't "normal." However, I did make it clear that our transformer wasn't large enough to handle our current (before any EV mods) demand.
A 50A circuit is clearly more typical. I still feel it depends on the situation. How much of the existing 200A (or any size for that matter) service is the house in question already capable of demanding? There have been numerous examples on TMC alone of folks who were just gonna throw in a 50A circuit when their house clearly couldn't handle it without an upgraded panel, or service.
I've said this before, the UMC should not be used indoors and should not be used on a daily basis. It is an emergency item to be carried in the trunk for ad hoc charging outdoors or in a parking garage (concrete bunker) situation. Even so you need to feel the connectors/adapters for any heat beyond 'warmth', and supervise the entire charge cycle.
In this case I'm surprised the car did not shut down the charging when the voltage dropped as amps increased/arcing commenced. This is what's scary.
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In this case I'm surprised the car did not shut down the charging when the voltage dropped as amps increased/arcing commenced. This is what's scary.
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What's the basis for this comment? Can you provide the engineering analysis for this? A great number of owners charge with the UMC daily and Tesla has never stated that this practice isn't recommended. If they feel that the UMC is engineered for daily use, what additional knowledge do you have to support a differing opinion?
Wattson
Member
I agree with SteveH. The Tesla Stores actually recommend owners install a 14-50 outlet and use the UMC.
I fully agree!
I wrote a blogpost about this (in Dutch though).
The UMC is great for charging on road trips or as an emergency, but it should imho not be used for daily charging.
I always advise owner to invest in a dedicated charging station (Again, EU) instead of using the mobile connector on daily basis.
Wear and tear on the adapters will slowly decrease the contact surface thus increasing electrical resistance and generating more heat.
Eventually this will lead into a melting adapter.
I'm still stunned by the fact that Tesla recommends the UMC for daily usage.
I have been reading the forums since April 2011 and have not read that the UMC is an emergency item. If that was true I would be shocked!
I use my UMC everyday but usually charge at or below 15 amps. When I am on vacation it is set at 5 amps. Almost no cable or connector warmth at 5-15 amps.
Every charging solution for the Model S involves some type of metal on metal connection. Plugging the HPWC into the car also is a metal on metal connection. All of those metal on metal connections are subject to wear. It sounds like your assumption is that it's impossible to design a connection that can be plugged and unplugged daily without eventually causing undue heat. If so, we're all doomed.
+1 I agree Steve. Wycolo, most people charge daily on their UMC, following the explicit instructions of Tesla to install a 14-50 in their garage. Me being one (but glad I have 400 Amp service to my house). I'm sure none of us stay up each and every night to "supervise the charge cycle". The UMC is a daily charging device AND can be carried in the trunk.
Tommy
Member
I don't envision any wear and tear on the adaptor(s) if the UMC is not being unplugged to take on road trips. I purchased a second UMC to use just for road trips and use my original UMC for home charging; it never gets unplugged.
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