Garage Wiring Fire

[wycolo]

I've looked at it and used it on occasion. My engineering analysis: a cheap piece of crap that I wouldn't trust behind my back for a second. Stays in the trunk.

Inside a building use ONLY wall mounted EVSEs: Aeroviron, Schneider, Clipper Creek, Tesla's HPWC, etc properly connected. Or mount them on an outdoor post or wall. My 14-50 box will be on a post outside, just like in an RV Park.

When re-activating a long unused service line like a 30 Amp dryer circuit, which would be perfect to source an EVSE, open up the boxes at each end, inspect the wires, and untighten/retighten all the connections just like you were doing a new install. Little known fact: all cable ends are readily accessible by removing cover plates or box covers (breaker boxes, distribution boxes) somewhere in the house. So you can see all the connections going back to the meter, and all of them should be checked before new usage. Ok, everyone knows this fact but often avoid doing it thoroughly.

Million dollar home, $100k car, why not charge with a cheap piece of crap??

Hey, you asked. :smile:
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[hfmalom]

I need to add that I did read on this forum that the 14-50 outlet was not engineered to have the cables pugged and unplugged (a warning from an electrician) on a daily basis.
I have two UMC cables. One is in the car (never used) and one is permanently mounted in the garage. The garage UMC with adaptor was plugged into the outlet in May 2013 (and never unplugged).
I did this to reduce (or eliminate) the wear and tear on the outlet and the adapator.
So I am a little bit paranoid about charging my car!

 

[Lloyd]

I make it a habit of touching the box and connector while charging occasionally to see if there is any excess heat buildup. Additionally I have re-torqued my connections at the breaker box and initially checked those connections for heat buildup.

The acceptable operating temperature of a circuit breaker is defined by UL in the UL489 standard (June 2011), which is listed below.



Terminations for standard rated breakers: Paragraph 7.1.4.2.2 says the temperature rise on a wiring terminal at a point to which the insulation of a wire is brought up as in actual service shall not exceed 50°C (90°F).



Terminations for 100% rated breakers: Paragraph 7.1.4.3.3 says the temperature rise on the termination shall not exceed 60 deg. C (108 deg. F).



Handles, knobs and other user surfaces: Paragraph 7.1.4.1.6 says the maximum temperature on handles, knobs, and other surfaces subject to user contact during normal operation shall not exceed 60°C (140°F) on metallic and 85°C (185°F) on nonmetallic surfaces.

 

[Tommy]

I've looked at it and used it on occasion. My engineering analysis: a cheap piece of crap that I wouldn't trust behind my back for a second. Stays in the trunk.

Inside a building use ONLY wall mounted EVSEs: Aeroviron, Schneider, Clipper Creek, Tesla's HPWC, etc properly connected. Or mount them on an outdoor post or wall. My 14-50 box will be on a post outside, just like in an RV Park.

When re-activating a long unused service line like a 30 Amp dryer circuit, which would be perfect to source an EVSE, open up the boxes at each end, inspect the wires, and untighten/retighten all the connections just like you were doing a new install. Little known fact: all cable ends are readily accessible by removing cover plates or box covers (breaker boxes, distribution boxes) somewhere in the house. So you can see all the connections going back to the meter, and all of them should be checked before new usage. Ok, everyone knows this fact but often avoid doing it thoroughly.

Million dollar home, $100k car, why not charge with a cheap piece of crap??

Hey, you asked. :smile:
--

Counterpoint; I don't believe the UMC is a "cheap piece of crap". It's sized for the job 40A continuous. The HPWC is more robust, it has to be as it's sized for up to 80A continuous. As much as you don't want to jeopardize a million dollar home and $100k car, I have no doubt Tesla dosen't want to jeopardize their mission or multi-Billion dollar business on a "cheap piece of crap."
BTW, good advise on checking the home wiring before placing the car into service.

 

[ecarfan]

I already planned to put a nest smoke detector in the garage as a back up.

I just bought 5 Nest detectors for my house and garage to replace the traditional type of smoke detectors. I am going to put one on the wall above my HPWC and 240V outlet. I had them professionally installed and am not worried about them, but better safe than sorry...

 

[markb1]

I just bought 5 Nest detectors for my house and garage to replace the traditional type of detectors. I am going to put one on the wall above my HPWC and 240V outlet. I had them professionally installed and am not worried about them,but better safe than sorry...

Be aware that Nest recommends against putting these in the garage. I think it's partly due to CO2 producers (ICEs, water heater, etc.) which you may or may not have in your garage. Also, if your garage is dusty, or gets very cold or very hot, it could be a problem.

 

[jcaspar]

Me too. I only plug/unplug it for charging away from home, the same amount I would if I had a spare one. Maybe a few times a year.

Daily usage does not mean plugging in and unplugging the UMC every day. For daily driving I think most owners do as I do, keep it plugged in and hang the cord on a hook on the wall, and only unplug the UMC to take it on long distance trips.

 

[JPP]

I need to add that I did read on this forum that the 14-50 outlet was not engineered to have the cables pugged and unplugged (a warning from an electrician) on a daily basis.
I have two UMC cables. One is in the car (never used) and one is permanently mounted in the garage. The garage UMC with adaptor was plugged into the outlet in May 2013 (and never unplugged).
I did this to reduce (or eliminate) the wear and tear on the outlet and the adapator.
So I am a little bit paranoid about charging my car!

For that reason I own 2 of the NEMA 14-50 adapters for my UMC. I leave the adapter in the wall and disconnect the UMC at the adapter before throwing it into the tote bag in the trunk. Thus essentially no fatigue from insertion-removal of the adapter.

 

[ecarfan]

Be aware that Nest recommends against putting these in the garage. I think it's partly due to CO2 producers (ICEs, water heater, etc.) which you may or may not have in your garage. Also, if your garage is dusty, or gets very cold or very hot, it could be a problem.

Thanks, I didn't know that. Just got the Nests. Will read the manual.

 

[mknox]

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.

Indeed. A Model S with Twin Chargers is like adding 4 homes to the local distribution system from a capacity planning point of view. The reason is the lack of diversity with EV charging loads. Most loads in the home cycle on and off. The oven gets up to temp and cycles. Electric heat cycles. Water heaters cycle. Utilities plan on a certain diversity in loads, meaning that not everything in everyone's home will all be on at the same time. But EVs come on full power for the entire charge cycle. Add a couple of these to a local distribution transformer and you've got trouble if it isn't upgraded. Having said this, most utilities are happy to upgrade infrastructure to capture the extra revenue they'll realize. There are exceptions: in some cases, larger pad-mount transformers may not fit on existing bases and civil work is required. Smart Grid technologies like controllable chargers are just starting to be explored.

 

[William13]

The UMC does have issues. Several melt downs have occurred. Mine may have wiring issues ( it is positional). The more important problem with daily use is the most NEMA 14-50 receptacles are not made to tolerate 10,000 in and out pluggings.

 

[jerry33]

Daily usage does not mean plugging in and unplugging the UMC every day. For daily driving I think most owners do as I do, keep it plugged in and hang the cord on a hook on the wall, and only unplug the UMC to take it on long distance trips.

That is certainly what I do.

- - - Updated - - -

The more important problem with daily use is the most NEMA 14-50 receptacles are not made to tolerate 10,000 in and out pluggings.

But normally you just leave the UMC plugged in. The only time you unplug it is on trips and to have it inspected by the Service Centre. So maybe twenty times a year.

 

[bareyb]

My Car is plugged in whenever it's not in use. Just as I was instructed to do by Tesla when I picked it up. I do set it to charge at 30 Amps instead of 40 but I do that more to increase the life of the battery pack than for any perceived safety issues. Just make sure any adapters you have attached to the charger cable are seated fully. It's been the loose ones that have heated up and melted. So far, mine charges just fine without any heat build-up at all.

 

[ThosEM]

We don't (so far) pack the mobile cable for daily commutes, so we don't work with the wall outlet daily and in fact have not pulled it out since we first installed it. Does it need to be in the car for some reason of which we are unaware?

 

[qwk]

The UMC does have issues. Several melt downs have occurred. Mine may have wiring issues ( it is positional). The more important problem with daily use is the most NEMA 14-50 receptacles are not made to tolerate 10,000 in and out pluggings.

While the UMC had issues, plugging it in/out 10,000 times is not going to wear out the male Tesla 14-50 end. It might wear out the $8 female outlet(most RV parks have wore out 14-50 outlets), but that is not on the Tesla side.

 

[flybob08]

We keep ours plugged in full time. Bought an extra cable to keep in the car. Have never used it in 12K miles!

 

[jamieb]

Seems to me that Tesla could sell a hard-wired version of the UMC, similar in form factor to the HPWC, that folks could install in their garage and completely forgo the plugging and unplugging of the UMC to leave it in the car for traveling. It would have to be <$500 to make sense, though - the price of EVSE's is dropping, and it's likely there will be good ones <$400 soon that you could use with the J adapter and just install in the garage.

 

[AmpedRealtor]

Seems to me that Tesla could sell a hard-wired version of the UMC, similar in form factor to the HPWC, that folks could install in their garage and completely forgo the plugging and unplugging of the UMC to leave it in the car for traveling. It would have to be <$500 to make sense, though - the price of EVSE's is dropping, and it's likely there will be good ones <$400 soon that you could use with the J adapter and just install in the garage.

Tesla already makes this, it's called the HPWC. The HPWC is a hard wired solution that can be used with any breaker up to 100A. The dip switches in the HPWC limit the current according to the circuit breaker that is installed. If you want to "hard wire" a 50A circuit for use by your Tesla, use the HPWC and set the dip switches to 50A breaker. That is your hard wired solution. Tesla gives you two choices - a hard wired solution in the HPWC for $1,200 or a pluggable solution with the UMC for half the price. Pick one or more.

 

[widodh]

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.

But usually those connectors/adapters aren't used under full load for 8 ~ 10 hours. That's the big problem.

Just a small bit of wear on those connectors can cause them to overheat and melt (We've already seen multiple examples of that).

Now I'm in the EU, but from what I've seen from the Nema 14-50 connector it's not something the big public should use for their every day charging. I'm also talking about the n00b here who has not a clue of what's happening.

We should not lure them into using the UMC, those people should simply buy a HPWC (even at 40A) or some other EVSE for at home. Simply Plug&Play.

Most of us here know what we are doing, but we should keep in mind that not everybody who will buy a Tesla in the future understands Volts and Amps.

Tesla already makes this, it's called the HPWC. The HPWC is a hard wired solution that can be used with any breaker up to 100A. The dip switches in the HPWC limit the current according to the circuit breaker that is installed. If you want to "hard wire" a 50A circuit for use by your Tesla, use the HPWC and set the dip switches to 50A breaker. That is your hard wired solution. Tesla gives you two choices - a hard wired solution in the HPWC for $1,200 or a pluggable solution with the UMC for half the price. Pick one or more.

I'd rather see Tesla giving people a HPWC with the car and let them buy a UMC if they want to.

In the EU I'd give people a Type 2 <> Type 2 cable instead of a UMC.

To install a HPWC (US) or a Type 2 EVSE (EU) you require a skilled electrician who will make sure it's properly installed and the circuit is sized to the current going over the wires.

With a UMC the danger exists people start plugging into flaky outlets and causing fires on the long run. That would be bad for Tesla and EVs in general.

 

[AmpedRealtor]

I'd rather see Tesla giving people a HPWC with the car and let them buy a UMC if they want to.

In the EU I'd give people a Type 2 <> Type 2 cable instead of a UMC.

To install a HPWC (US) or a Type 2 EVSE (EU) you require a skilled electrician who will make sure it's properly installed and the circuit is sized to the current going over the wires.

With a UMC the danger exists people start plugging into flaky outlets and causing fires on the long run. That would be bad for Tesla and EVs in general.

I tend to agree. I've always viewed the UMC as a way to plug-in when you are on the road and need the flexibility to hit a variety of outlets in the absence of a supercharger. I've never viewed the UMC as a means by which to charge my car in my own garage. For that I purchased the HPWC. I can't imagine anyone charging with just a single UMC, removing it from the receptacle each day when they leave. That is a lot of wear/tear on the receptacle.