Are you using a Residential-rated receptacle Then an EV Industrial Rated receptacle to charge?

[Dusty]

The electrician arrived this morning to plan and quote installing 60A outlet for me. I'm not telling him it's for my Tesla wall charger.

A previous electrician said installing an EV wall charger was $1200 bucks last week. This was to run a line up the wall across the ceiling and down a wall.

I'll see if the Tesla tax from electricians is true, when he gets back to me with the numbers.

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[HaulingAss]

I did this install at our ski cabin in 2019 with a 60A 240V breaker, underground conduit, a 35' run of 1" Schedule 80 PVC conduit and three AWG #6 copper conductors rated for in ground use and one 35' ground wire. The cost for all electrical equipment (all copper wires, circuit breaker, conduit, and all misc. conduit fittings, pipe glue, etc.) was only $165 worth of supplies purchased from the local hardware store. It would have been less but I ran one un-needed AWG #6 conductor to "future-proof" the underground wiring run in case anyone ever wanted to turn it into an outlet and oversized the copper ground wire from the required AWG #10 to AWG #8.

I believe the end result is better than if I hired a contractor or licensed electrician because I was meticulous about every detail with an eye to longevity and keeping the oxidation of the copper connections to a minimum. It's been performing perfectly for over three years through all kinds of nasty weather without so much as a glitch. None of the connections, including the breaker, become anything more than slightly warm after charging for a couple of hours at 48 amps. It adds around 45 miles of range per hour of charging and allows me to start my ski morning with a warm cabin and full "tank" of electricity.

This was so much better than the Mobile Connector that I used through the first winter, mostly because it's faster and far more convenient.

 

[HaulingAss]

A hard wired connection is not intrinsically superior. Speaking of bad advice...

Hard wiring is absolutely superior in terms of safety, efficiency and even convenience (allowing you to keep your Mobile Connector in the vehicle for a potential road emergency). I use both a Wall Connector and also have a Gen 1 Mobile Connector capable of 40 amps from a NEMA 14-50 and a Gen 2 Mobile Connector capable of 32 amps from the same outlet.

Both of my Mobile Connectors emit more heat than the Wall Connector because the wires are thinner and have more resistance. The NEMA 14-50 receptacle is high quality and industrial grade but there is still unnecessary heat being generated (you can feel it) after an hour or more of charging. The Wall Connector is also more robust because the larger packaging allows for heavier duty components so it's likely to be more durable over time.

Safety wise, avoiding the resistance between the electrical plugs blades and the receptacle contacts means less chance for heat buildup as components age and the copper oxidizes. If you don't have an outlet and a plug, that's one less thing to maintain and to go wrong. The copper blades on my plug need periodic cleaning because the natural patina they get acts as a resistor. Fires happen in the NEMA 14-50 outlets for numerous reasons including poor quality outlets, but a contributing factor is there are two sources of heat in a very small area: the screw terminals and the contacts that grip the blades of your electrical plug.

Either method works but the hard-wired solution is considerably superior for multiple reasons. Charging a smaller EV like the Model 3 can involve 32-48 amps of 240V current for hours continuously and the Cybertruck will consume even more energy per mile driven and will use at least as much current so I recommend that reservation holders who plan to convert their reservations into deliveries start thinking about how they could get their own Wall Connecter installed and operational before they take delivery. A Mobile Connector and NEMA 14-50 outlet is the next best thing but why settle for that when it's not any more work to install a Wall Connector?

 

[rr6013]

I believe the end result is better than if I hired a contractor

Add ground fault tolerant sub panel someday… you’re all good

 

[ÆCIII]

There are always dangers in carelessness of humans disregarding the National Electrical Code and local safety codes.

I think this is one reason that Tesla added their own safety margin of being 20 percent under the rated current draw for a given circuit and it's wire size, when configuring a Wall Connector installation or selecting a current limiting UMC adapter.

However, sometimes unwise people will ignore codes and draw excessive current above the rated capacity of smaller wires, by either 'over-fusing' the circuit (putting in a larger amperage breaker than the wire size is rated for), or putting a larger amperage rated outlet on smaller lower capacity wires - in which either case a current bottleneck could generate heat and melt something.

The Tesla UMC adapter only can trust the inserted end and it's programmed current rating being plugged into a properly installed circuit and outlet. However, if the rated receptacle is connected to smaller (lower amperage capacity) wires, the UMC and adapter combination has no way of knowing this and could draw more current than those wires are rated to handle.

Likewise, if someone configures their wall connector incorrectly to draw more current than the circuit is rated for - the wires can overheat especially since charging can take a while. However I think I remember reading in the instructions there is overheat sensing circuitry in the wall connector to intervene in the event the connector gets too hot, but I'm not certain.

I find it a little bit laughable that some are calling outlets "EV Rated" vs "Dryer Rated", because the outlet will never know the purpose of the current flowing through it. The current rating of an outlet is in a certain amount of Amps, and that is what it is designed to handle, and it should be designed to handle it for sustained periods of time. A dryer can be used for hours on end if there is a large household, or someone comes over to add their laundry to borrow someone's dryer. NEMA outlets of higher amperages are also used for stoves and welders, which can also get used for long periods of time, depending on activity in the kitchen or workshop. If there has to be such a thing as "EV Rated" outlet then I think UL is missing something in it's testing of outlets in general. Again, since the Tesla UMC or wall connector also draws 20 percent less current than it's configured circuit capacity, I see the need for such "EV Rated" outlets as a little over hyped. I could be missing something though.

I also find it interesting that now four years after the Model 3 ramp up, this is suddenly a 'thing'. I don't think it would be widespread, because we'd certainly have heard more about it before now if it were happening often.

But what does not surprise me is the capacity of some humans to ignore instructions, regulations, safety, and common sense.

- ÆCIII

 

[SwampNut]

For a variety of reasons, I ended up with a ton of various wire rolls in #10 up to #4. It let me run my own 70a subpanel to one garage for a bunch of 240v 20-30a tools, the Tesla mobile adapter outlet, and a couple other projects...for nothing.

They were castoffs from partners in a datacenter, and a vendor, etc. They won't use small rolls so my 70' sub panel run was a throw-away to them. Probably $600 today.

 

[HaulingAss]

I just checked the pricing of AWG #6 THHN wire at Home Depot (where I bought it in 2019). It's about triple what I paid for it, still very reasonable price for all but the longest distance EV charging installs ($1.58 when buying by the foot). Considering that copper wiring can last longer than the person installing it, it doesn't seem all that expensive to me.

You know what's expensive? That's right, gasoline. And it only lasts until you use it to go to one desitnation and then it's gone. Gas hose is really expensive too, so don't try to install a gas pump in your driveway.

 

[HaulingAss]

There are always dangers in carelessness of humans disregarding the National Electrical Code and local safety codes.

I think this is one reason that Tesla added their own safety margin of being 20 percent under the rated current draw for a given circuit and it's wire size, when configuring a Wall Connector installation or selecting a current limiting UMC adapter.

However, sometimes unwise people will ignore codes and draw excessive current above the rated capacity of smaller wires, by either 'over-fusing' the circuit (putting in a larger amperage breaker than the wire size is rated for), or putting a larger amperage rated outlet on smaller lower capacity wires - in which either case a current bottleneck could generate heat and melt something.

The Tesla UMC adapter only can trust the inserted end and it's programmed current rating being plugged into a properly installed circuit and outlet. However, if the rated receptacle is connected to smaller (lower amperage capacity) wires, the UMC and adapter combination has no way of knowing this and could draw more current than those wires are rated to handle.

Likewise, if someone configures their wall connector incorrectly to draw more current than the circuit is rated for - the wires can overheat especially since charging can take a while. However I think I remember reading in the instructions there is overheat sensing circuitry in the wall connector to intervene in the event the connector gets too hot, but I'm not certain.

I find it a little bit laughable that some are calling outlets "EV Rated" vs "Dryer Rated", because the outlet will never know the purpose of the current flowing through it. The current rating of an outlet is in a certain amount of Amps, and that is what it is designed to handle, and it should be designed to handle it for sustained periods of time. A dryer can be used for hours on end if there is a large household, or someone comes over to add their laundry to borrow someone's dryer. NEMA outlets of higher amperages are also used for stoves and welders, which can also get used for long periods of time, depending on activity in the kitchen or workshop. If there has to be such a thing as "EV Rated" outlet then I think UL is missing something in it's testing of outlets in general. Again, since the Tesla UMC or wall connector also draws 20 percent less current than it's configured circuit capacity, I see the need for such "EV Rated" outlets as a little over hyped. I could be missing something though.

I also find it interesting that now four years after the Model 3 ramp up, this is suddenly a 'thing'. I don't think it would be widespread, because we'd certainly have heard more about it before now if it were happening often.

But what does not surprise me is the capacity of some humans to ignore instructions, regulations, safety, and common sense.

- ÆCIII

The safety of EV charging circuits has been a known safety "thing" since at least 2013 and the wider distribution of the Model S.

The National Electrical Code (NEC) requires the rated current of a circuit be reduced by 20% for any circuit likely to be in continuous use and specifies that EV charging falls into "continuous use" category. In other words, I agree with you that it's silly to talk about "EV rated" or "dryer rated" outlets. The problem is, there are marginal outlets on the market with amp ratings higher than they deserve.

 

[Ogre]

Went to Seattle and discovered the garage where the show was has free charging for EVs right at the exit to the garage. The best parking and getting it at a discount, just have to get there early which wasn’t a big deal, we just had food before the show.

 

[Jhodgesatmb]

See What Sandy Munro and Experts have to say.

Basically, it's better to use a direct line to your Charge unit which it was designed and rated to handle the long charging cycle.

The industry has not made EV-rated receptacles and circuit breakers for the long-duty cycles of charging an EV. (Most on the market rated for Dryer's duty cycle usage only). One of Sandy's hosts suggests that Hubbell does make a more robust type of receptacle which costs some $$$.

Home Charging Installation Risks and Advice

See at 7:44 for Wake up announcement to suppliers of receptacles & Circuit Breakers for EVs usage.

I saw that video and it was intended to scare the S#$T out of people and I found it scary. We have 2 Tesla wall connectors for our Model 3 and Model Y/Cybertruck. Both were installed by an electrician that has done a lot of this kind of thing. Both are on a separate panel from our home, with each having a 60-amp breaker. There is nothing special about the breakers and they are no knife type disconnects. I mention all of this because a couple months ago we had an event where we were charging both of the cars and running the washing machine all at the same time and, somehow, there was a disconnect from the grid and our generator kicked in. But there was still service from the grid. I checked all of the breakers and everything was fine. I called the utility and they sent out someone to look at it and we found that my transfer switch was stuck open. We turned off the generator, closed the switch, and all was back to normal, but I suspect that we pushed the system too hard. Long story short, I agree with the video that these high-load BEV residential charging scenarios have not been (and need to be) addressed. For our purposes, we are now only charging one vehicle at a time and after the wife has stopped doing anything with appliances. No new events since then.

 

[happy intruder]

Get a condenser dryer instead, much better for the clothes, and your power bill.

I have never heard of that kind of dryer.....what is it and how does it work

 

[HaulingAss]

I have never heard of that kind of dryer.....what is it and how does it work

It circulates slightly warm air over the tumbling clothes and rather than exhaust the warm, humid air, it passes it over a chilled condensor which removes the moisture from the air and continues to circulate the same air over the clothes. The water condensed from the air is typically directed into a drain.

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