Why I'm Scared to Leave My Tesla At Home

[dgatwood]

You keep justifying how great it is being on 110V and them blaming firmware and how you're scared to charge at home on a BAD setup. Sorry you can't have it both ways. Why bring it up at all if you don't need it? If you do "need it", even when it's only in a pinch, you'll probably want to be faster than 3 mph.

I'm not saying it's great. 110V charging stinks on ice even with a 20A outlet running at 4 MPH, much less a 15A outlet at 3 MPH. But for an outlet that I use single-digit times per year, typically at the minimum charge rate of 4A, just to get 10 extra miles or so overnight to reduce my range anxiety on the way to a supercharger (where I sit in my car and do work while I charge), spending thousands of dollars to get a 220V outlet that I will use at 2A just so that it won't trip a GFCI seems like a really bad use of money, particularly given that it is clearly a defect in the V2 UMCs that did not occur in the V1 UMCs.

And no, I did not say I was "scared to charge at home". I said I was scared to leave the car while on vacation, because of the possibility of random events entirely outside of my control causing it to consume an exorbitant amount of battery power. The Tesla service tech said it was waking up about every three hours or so, through the entire day and night. He even had me change my password, just in case some service somewhere was waking my car, but of course that didn't change anything.

You'd have to be constantly pulling more that 80A 220V to say you have maxed out your 100A panel.

It's not a capacity issue. I am already at the maximum number of circuits that the panel is rated for, with every slot but one filled, and only two non-tandem breakers in the entire box, and they're not anywhere near each other. So it would be a decent amount of work just to make it work even if I convinced a contractor to ignore the maximum circuits specification on the electrical panel.

But without violating either the electric code or the specifications, the only option would be a subpanel or a larger main panel, and at Bay Area labor rates, that would cost a few thousand dollars, last time I looked into it.

I didn't read every post and someone mentioned your running the fridge on the same circuit? Typically fridge should not be on GFCI (Fridge not a electricution risk and not worth the risk on a false trip losing all your food).

Same circuit, different GCFI. Each outlet has an independent GFCI (no downstream outlets) precisely for that reason. I can't put the fridge on a non-GFCI outlet (legally), because it is located in a bathroom.

 

[mswlogo]

I'm not saying it's great. 110V charging stinks on ice even with a 20A outlet running at 4 MPH, much less a 15A outlet at 3 MPH. But for an outlet that I use single-digit times per year, typically at the minimum charge rate of 4A, just to get 10 extra miles or so overnight to reduce my range anxiety on the way to a supercharger (where I sit in my car and do work while I charge), spending thousands of dollars to get a 220V outlet that I will use at 2A just so that it won't trip a GFCI seems like a really bad use of money, particularly given that it is clearly a defect in the V2 UMCs that did not occur in the V1 UMCs.

And no, I did not say I was "scared to charge at home". I said I was scared to leave the car while on vacation, because of the possibility of random events entirely outside of my control causing it to consume an exorbitant amount of battery power. The Tesla service tech said it was waking up about every three hours or so, through the entire day and night. He even had me change my password, just in case some service somewhere was waking my car, but of course that didn't change anything.




It's not a capacity issue. I am already at the maximum number of circuits that the panel is rated for, with every slot but one filled, and only two non-tandem breakers in the entire box, and they're not anywhere near each other. So it would be a decent amount of work just to make it work even if I convinced a contractor to ignore the maximum circuits specification on the electrical panel.

But without violating either the electric code or the specifications, the only option would be a subpanel or a larger main panel, and at Bay Area labor rates, that would cost a few thousand dollars, last time I looked into it.




Same circuit, different GCFI. Each outlet has an independent GFCI (no downstream outlets) precisely for that reason. I can't put the fridge on a non-GFCI outlet (legally), because it is located in a bathroom.

There is no way it cost thousands to squeak a 20A 240V circuit in. Even in the Bay Area.

Ok now you’re sharing the bathroom GFCI, Fridge and EV charging on the same circuit. And your scared to Charge at home? Are you by chance standing in the (full) tub passing the UMC cable through the window of the bathroom too while plugging it in? And you’re worried about doing things legally?

I rest my case. I vote this being dumbest thread of the week.

 

[immolated]

Same circuit, different GCFI. Each outlet has an independent GFCI (no downstream outlets) precisely for that reason. I can't put the fridge on a non-GFCI outlet (legally), because it is located in a bathroom.

Again it's not a legal thing. You can do whatever you want to your house, it just won't be "in code". Which is only something you need to worry about if selling or renting.

 

[Gasaraki]

Why in the h$&@ do you have your Model X plugged into a 110v GFCI !?? Ground faults and pop machines don’t mix because there is a delay with the current returning to the outlet when the compressor starts. If I recall, the GFCI only allows a 5 millisecond delay. Something like that might be occurring with your GFCI. Outlets are easy peasy to wire.
Please hire a qualified person to wire you a decent outlet to provide juice for your car.

Tesla specifically says not to plug in to a GFCI plug.

 

[VikH]

I'm in California. At our extortionate utility rate, given the number of miles I drive each week (at least when the coronavirus doesn't have everything shut down), I've calculated that I would spend about $66 per week in electricity if I charged at home. That's over three grand per year. If a replacement battery costs $15k, then at five years, the power savings from supercharging has more than paid for the cost of a replacement battery. The warranty on the battery is 8 years. It makes zero sense to charge at home.

Even if it costs as much as you say, the main disadvantage with using a Supercharger for your daily needs is the TIME it takes. It seems like such an inconvenience (especially in CA where SCs are full), that I would look at getting a Model 3/Y LR for better efficiency or switch to a gas car.

Also, AFAIK, they aren't throttling 100Ds.

Yes, they are. Once you hit a certain amount of DC charging you won't be able to go above 100kw at a SC. There are a handful of threads in the Model X and S forum.

I rest my case. I vote this being dumbest thread of the week.

I agree.

 

[Rocky_H]

I can't believe the dark humor of a person with the username @immolated advocating violating electric code.

 

[dgatwood]

Even if it costs as much as you say, the main disadvantage with using a Supercharger for your daily needs is the TIME it takes. It seems like such an inconvenience (especially in CA where SCs are full), that I would look at getting a Model 3/Y LR for better efficiency or switch to a gas car.

And again, the supercharger is only fifty feet away from where I get food on my evening route, and I do work for my employer while I wait, so the time spent supercharging is exactly zero.

And no, the supercharger I use has never had more than about 6 cars out of 15 stalls so far.

 

[dgatwood]

There is no way it cost thousands to squeak a 20A 240V circuit in. Even in the Bay Area.

Ever price out a new subpanel? Didn't think so.

 

[mswlogo]

Ever price out a new subpanel? Didn't think so.

No, I do my own work.

I also know exactly what's involved, probably $500-ish in the Northeast. I know Calif is expensive but it's not that expensive.
It's about $50-$100 in parts and a couple hours labor. Looked it up, $1100.00 ($1100 to you in Calif is the same "pain" as $500 in the Northeast).

 

[dgatwood]

No, I do my own work.

I also know exactly what's involved, probably $500-ish in the Northeast. I know Calif is expensive but it's not that expensive.
It's about $50-$100 in parts and a couple hours labor. Looked it up, $1100.00 ($1100 to you in Calif is the same "pain" as $500 in the Northeast).

Let's put it this way: My estimate is based on the quotes that other folks where I work have been quoted for this sort of work. The number I usually see is $1,500 for a simple outlet, $3,000 for an EVSE charger, and that's if they don't have to do anything special, like upgrading the box or adding a subpanel. I'm not saying you can't do it cheaper, but I highly doubt you'll find anyone who will do a breaker box replacement for under $3k unless you're willing to let them do it without a permit.

The main problem is that the permitting process out here is an absolute nightmare. Most folks seem to tack on the better part of a grand as soon as you tell them they have to pull a permit, just because it is such a huge hassle. Basically, they spend hours sending the permit back to the county (or city, depending) over and over and over before they finally accept the paperwork.

I wish I were kidding. I've regularly seen permits come back three or four times, and I've seen relatively minor electrical work go over their time estimates by as much as two months because of the inspection process. It's absolutely insane.

 

[dmurphy]

Let's put it this way: My estimate is based on the quotes that other folks where I work have been quoted for this sort of work. The number I usually see is $1,500 for a simple outlet, $3,000 for an EVSE charger, and that's if they don't have to do anything special, like upgrading the box or adding a subpanel. I'm not saying you can't do it cheaper, but I highly doubt you'll find anyone who will do a breaker box replacement for under $3k unless you're willing to let them do it without a permit.

Wow - those prices are completely out of whack with reality!

I recently had a new 30a circuit ran to my basement for my home office & computer equipment - that was $300. And permitted.

HPWC install was $600. Same thing.

Breaker panel replacement with service upgrade to 200A in my previous home was $1200.

It’s not like we’re exactly rural here, either. I’m ~30 miles due west of Manhattan. Not too often I feel glad to be in the NY metro area, but this is one of them!

 

[VikH]

And again, the supercharger is only fifty feet away from where I get food on my evening route, and I do work for my employer while I wait, so the time spent supercharging is exactly zero.

And no, the supercharger I use has never had more than about 6 cars out of 15 stalls so far.

Still sounds like a pain compared to just plugging in when you get home. What happens when you reach your DC limit and Tesla slows down your SCing?

 

[mswlogo]

Still sounds like a pain compared to just plugging in when you get home. What happens when you reach your DC limit and Tesla slows down your SCing?

He charges at work. It won’t slow down unless you SC nearly 100%.

 

[rhumbliner]

I believe you are allowed a Non-GFCI outside, but it must be labeled as such. I have one outside that powers a water softener and we were having trouble with it tripping. Non-GFCI, labeled and problem solved.

Do you have a reference for this? I’ve been poring over the NEC looking for this exception and can’t find it.

 

[mswlogo]

Do you have a reference for this? I’ve been poring over the NEC looking for this exception and can’t find it.

Appliances that are normally not unplugged might have exceptions. Like a Fridge or Dryer does not require it even though they are in Washrooms and Kitchens. EV requirement is new because they CAN be frequently unplugged. Outdoors or even in wet garage from snow or rain plugging in and out is high risk. So EV Code requirements changed. I don’t believe there is an exception for EV. GFCI on EV is generally not a problem, you just need a GFCI that is compatible. I had to switch out my GFCI on a pool pump when I replaced it with a DC variable speed pump. It has a large AC to DC converter just like the charger in the Tesla. Very well know problem. The electrical supply knew exactly what was wrong and what GFCI would fix it. It would randomly trip just like OP.

 

[Rocky_H]

What happens when you reach your DC limit and Tesla slows down your SCing?

He will continue to Supercharge. Perhaps you are not familiar with how that limiting worked. It was mainly just a cap of the very top highest power limit, but it didn't slow down the entire thing all through the entire session. So only if you were at a very low state of charge and could have been able to get like 120kW+, it would limit that to maybe 90-100 max. But that high rate would usually only last for the first 5-10 minutes, and then it's down into the battery tapering curve anyway, where the capped or uncapped isn't really making much difference, because the battery is keeping a lower rate anyway.

 

[Yinn]

Ok, I'm not going to jump on you but I do have a LOT of questions.

My Tesla Model X (2017) has always had issues with charging at home. It trips the groundfault breaker. The original breaker tripped instantly when I started charging, as soon as it started drawing power. The replacement GFCI outlet just trips randomly after half a day or so.

Can you elaborate please? Is it tripping a GFI/GFCI breaker on the panel? Or is it tripping a GFCI outlet? Or has it done both?

• Fix the UMC v2 design so that it doesn't leak enough current to constantly trip 110V GFCI outlets.

I've used my UMC on a dedicated 20amp/120V circuit with a breaker GFI without any issues. It's also been used as a 14-50 with a dedicated 60amp/240V circuit with a breaker GFI without any issues of tripping.

spending thousands of dollars to get a 220V outlet that I will use at 2A just so that it won't trip a GFCI seems like a really bad use of money, particularly given that it is clearly a defect in the V2 UMCs that did not occur in the V1 UMCs..

Not everyone is up for it, but a panel from lowes - one of the value bundles that comes with breakers costs roughly $50. You can get it on sale for about $30. EMT conduit to make life easy, misc fasteners, even through on a 14-50, etc. That $3000 job becomes $100, then it depends on your towns permits. Mine was done for under $500 total for a new sub panel with 14-50, HPWC, and a dedicated GFI outdoor outlet. I went back and forth with my own town myself and saved a bunch this way.

If you're nervous about it, find an electrician that's willing to certify your work for permitting but that will bring it to at least $1000 again.

It's not a capacity issue. I am already at the maximum number of circuits that the panel is rated for, with every slot but one filled, and only two non-tandem breakers in the entire box, and they're not anywhere near each other. So it would be a decent amount of work just to make it work even if I convinced a contractor to ignore the maximum circuits specification on the electrical panel..

Have you done electrical tests on the circuit to see what comes back? Average draw? Peak? Or a ground fault test? Using an actual tester not the button the switch

Can you also take a picture of the electrical box and the wires coming out of the box? It sounds like you have an older home based on the 100A. So it's also entirely possible you have a breakage in the wires that's causing a fault.

 

[Rocky_H]

It's also been used as a 14-50 with a dedicated 60amp/240V circuit

I hope that's a typo.

 

[Lloyd]

Do you have a reference for this? I’ve been poring over the NEC looking for this exception and can’t find it.

Looking, Code requires it for new construction, but does not require upgrade. If your house was built before it became code, (1973), you would not be violating code to put a non-gfi plug outside. Understand that you will not have the protection that GFI offers you.

 

[Yinn]

I hope that's a typo.

Nope. Oversized that one due to the location of the 14-50 box. That way I can turn that outlet into a junction box if need be without running additional wiring or install a HPWC if I wanted. Don't worry, the #4 wiring supports 60A so it's not just a breaker. It's truly a 60A circuit and not just a 60A breaker.