MYLR + Mobile Charger tripping breaker??

[Colorado Y]

I've put about 1500 miles on my Y. Nearly all of my charging has been at home, on my Mobile Charger. Recently I've had several charging sessions get interrupted because the circuit breaker popped. There is almost nothing else on that circuit (just a sprinkler controller, sometimes a charger for my mower) so most of the time the car charges on a private 20A circuit. Most recently, with nothing else on the circuit, it popped the breaker THREE TIMES in about an hour.

Has anybody had a problem with this? Do I have to set my charge rate below the 12A default?

 

[Rocky_H]

First off, how is it tripping? These are garage outlets, which have those GFCI detection in them. Is it the GFCI in one of those that needs to be reset, or is it the main breaker that is opening, like it's too much current? The charge cable does a ground test when it initializes, where it trickles a little current onto the ground pin, and that can set off finnicky or aged GFCIs.

But if it's just the regular breaker, yes, you might need to turn the current down since it is shared with other things. There's not a lot of room left for anything else on the circuit, so you might need to leave some extra amps there. Or that breaker could be old too.

 

[Colorado Y]

No GFCI on this circuit, just the 20A breaker. (I think ?? I don't see a GFCI on it, but maybe there's another outlet hidden behind other stuff. NEC requires GFCI in garages, but that was added to the code in 2008 -- 18 years after the house was built.) Shouldn't be running out of amps -- the car is drawing max 12A of the available 20A, and other loads are usually in the milliamp range. I've had it trip when NOTHING else was running. I should try charging the car with nothing else even plugged into the circuit.

"Old breaker" was my brother's theory too. It's about 32 years old.

 

[skydve1]

"Old breaker" was my brother's theory too. It's about 32 years old.

I was going to suggest that as well. They get weak over time. They're cheap and very easy to replace.
You can also wire up a new outlet , using a new breaker and breaker slot - if one is available.

 

[Colorado Y]

There are no open slots, and we've already doubled up a few slots. (It's a big house.) I've been considering installing a 14-50 outlet, which I think would require 2 slots, meaning I'd have to double up another 2 slots.

 

[Mrbrock]

No GFCI on this circuit, just the 20A breaker. (I think ?? I don't see a GFCI on it, but maybe there's another outlet hidden behind other stuff. NEC requires GFCI in garages, but that was added to the code in 2008 -- 18 years after the house was built.) Shouldn't be running out of amps -- the car is drawing max 12A of the available 20A, and other loads are usually in the milliamp range. I've had it trip when NOTHING else was running. I should try charging the car with nothing else even plugged into the circuit.

"Old breaker" was my brother's theory too. It's about 32 years old.

If there was a hidden GFCI outlet that was tripping, you wouldn't be tripping the breaker. And the circuit wouldn't work until the GFCI outlet was reset.

 

[skydve1]

There are no open slots, and we've already doubled up a few slots. (It's a big house.) I've been considering installing a 14-50 outlet, which I think would require 2 slots, meaning I'd have to double up another 2 slots.

You should be able to add a sub-panel, and add the EV charger and some other outlets to the sub-panel.
And yes, the NEMA 14-50 outlet requires 2 slots (double breaker).

 

[240vPlug]

Lower the amperage down to 8 amps and see if it still trips. With the age of that circuit I wouldn’t use that to charge your EV long term.

I would suggest spending the money for a good proper home charging setup. I would suggest a hard wired EVSE like the wall connector. A 14-50 is not a good solution long term and requires a GFCI breaker which could cause nusciance tripping.

Wall comnector is $400 (lower price) and you can keep your mobile connector in your car in the even you ever need it while traveling away from home.

 

[Colorado Y]

D'oh!! Good point @Mrbrock.

There's actually already a small sub-panel, installed 20+ yrs ago for a generator hookup. And it's full too. But I could add another one.

I'd rather not get a wall connector. I really don't need it. So far I'm only driving about 100 miles a week. People who commute 100mi every day run through their charge a lot faster, but plugging in the Mobile Connector every few days handles my charging needs just fine, other than the circuit breaker issue. I only use Superchargers if I go on a road trip.

If I can't resolve the breaker problem, I can always go for a wall charger later.

 

[SSonnentag]

Try swapping the breaker with another circuit. If that solves the problem or the problem moves to the other line, it was a weak breaker.

 

[Tronguy]

Just chiming in with the thought that this is a weak breaker. Almost all breakers are heat-operated; that is, heat an element up in the breaker enough, it expands, and causes the breaker to trip.

You're running this at 12A and it's an old breaker. Every time you suck down current, that heating element in there is going to flex. If you're drawing 12A on a 20A breaker and the breaker is popping, yeah, old breaker.

On the other hand: Mobile Connectors have significant electronics in them. So does the car, in the rectifiers that convert AC to DC. Either of those could short and cause the problem. Minor suggestion: Find a serious heavy-duty, high current extension cord (one that's designed and says it can handle 15 or 20A), run that to another outlet in the house, one that, preferably, doesn't have a load on it, and see if a new breaker starts popping.

As a suggestion: Code has said for a while now that kitchen appliances, like the stove, refrigerator, garbage disposal, and microwave are all supposed to be on their individual circuits/breakers. Microwaves, in general, tend to be plugged into a dedicated socket rather than hardwired to the building wiring. So: Unplug the microwave, plug your car into that 15A socket up there, and let the car charge. If the breaker for the microwave pops then it's likely to be the car, not the breaker.

 

[davewill]

D'oh!! Good point @Mrbrock.

There's actually already a small sub-panel, installed 20+ yrs ago for a generator hookup. And it's full too. But I could add another one.

I'd rather not get a wall connector. I really don't need it. So far I'm only driving about 100 miles a week. People who commute 100mi every day run through their charge a lot faster, but plugging in the Mobile Connector every few days handles my charging needs just fine, other than the circuit breaker issue. I only use Superchargers if I go on a road trip.

If I can't resolve the breaker problem, I can always go for a wall charger later.

In your shoes, I would install some sort of dedicated charging circuit. There are several reasons:

1. 120v circuits are inefficient. The car has to run it's cooling pumps for longer when charging at such a slow rate.
2. Old 5-15/20 outlets get loose and get hot over time.
3. Every outlet this circuit is daisy-chained through between the car and the panel is another possible failure point.
4. Your circuit is old and is already having problems. Even if you fix this by changing the breaker, the rest of it is still old.

Even just stepping up to a dedicated 240v 20a or 30a circuit would be a big improvement.

You might be able to just replace that generator subpanel with one that has more capacity. Since the generator feeds the house, and the EV draws, you might be able to do both on the same feeder wire.

 

[Pianewman]

davewill: Agree with his post. Safety here is the primary objective, the "inconvenience" of circuit tripping is telling you something is wrong.

 

[Colorado Y]

Yup, I knew something was wrong. My first thought was that it was the car, but I agree the breaker is a likely suspect.

If I remember right, the circuit is pretty simple. I think it runs from the breaker panel to an outlet, and thence to the outlet I'm plugging the mobile connector into. I think I installed that circuit 20-25 yrs ago but I don't remember why ...

I'll swap in a new breaker and see how it behaves. Might take me a while.

 

[Pianewman]

Yup, I knew something was wrong. My first thought was that it was the car, but I agree the breaker is a likely suspect.

If I remember right, the circuit is pretty simple. I think it runs from the breaker panel to an outlet, and thence to the outlet I'm plugging the mobile connector into. I think I installed that circuit 20-25 yrs ago but I don't remember why ...

I'll swap in a new breaker and see how it behaves. Might take me a while.

Both of the red highlighted statements make me nervous. Time for a complete visual check of the circuit, IMHO, prior to simply swapping in a new breaker.

 

[davewill]

Yup, I knew something was wrong. My first thought was that it was the car, but I agree the breaker is a likely suspect.

If I remember right, the circuit is pretty simple. I think it runs from the breaker panel to an outlet, and thence to the outlet I'm plugging the mobile connector into. I think I installed that circuit 20-25 yrs ago but I don't remember why ...

I'll swap in a new breaker and see how it behaves. Might take me a while.

If it's the only outlet on the circuit, or if you can make it so, converting it to 240v would be pretty easy.

 

[Colorado Y]

There are two. I believe the first one was run to a "workshop area" in the garage when it was built, and then I daisy-chained another one off it. But I could remove the first outlet if necessary.

 

[davewill]

There are two. I believe the first one was run to a "workshop area" in the garage when it was built, and then I daisy-chained another one off it. But I could remove the first outlet if necessary.

What size wire? 240v/20a is a respectable choice. It will charge the car over three times as quickly as 120v/15a. Even 240v/15a is a big difference being well over twice as fast.

Assuming a 300w overhead (I actually think it's bigger...)

120v/15 circuit => 120v x 12a charging = 1440w - 300w = 1140w (1.0x) into battery
240v/15 circuit => 240v x 12a charging = 2880w - 300w = 2580w (2.3x) into battery
240v/20 circuit => 240v x 16a charging = 3840w - 300w = 3540w (3.1x) into battery

 

[Colorado Y]

Huh. I tried unplugging everything from that circuit, and plugged in my car. It ran overnight with no problems. Aha.

Just to be sure, I plugged in the mower charger &etc, the same light loads that had been on the circuit before. The car charged overnight with no problems.

That's the way it SHOULD work. Now I'm not sure why it tripped 3 times in an hour when I tested it last week ...

@davewill, it looks like the circuit is 14ga. I could easily swap out the romex on the extension I added. Replacing the breaker-box-to-outlet run (and the breaker, obvs) would be harder but probably do-able.

I've never wired a 240v circuit. I'd probably hire an electrician for that. If I add a 240v circuit, I assumed it would feed a 14/50 outlet. But it sounds like a 240v / 20A circuit would work fine -- 3.1x power to the battery would charge at about 15 miles per hour. That's plenty for my needs. I assume you'd use a 14-20R outlet for that? I'm not sure if a 6-20R would be a good idea or not.

Though if I'm running a new line, maybe I should future-proof it and go with 14-50 ...

 

[Rocky_H]

it looks like the circuit is 14ga. I could easily swap out the romex on the extension I added. Replacing the breaker-box-to-outlet run (and the breaker, obvs) would be harder but probably do-able.

I've never wired a 240v circuit. I'd probably hire an electrician for that.

This is the cool thing that makes it fairly simple though. 120V circuits versus 240V circuits use exactly the same wire. The wire just has to size with the amount of current, not the voltage. So it is literally just a matter of what you attach on the ends (breaker and outlet) that makes it a 240V circuit versus a 120V one.