Charging problems (240 and 110)

[Odedoralive]

So my in-laws have a recently built detached garage. They put a dedicated 30A breaker and 240v outlet for us to charge our Y when we visit. For some reason, charging constantly stops. The basic error of Communication Failure and Check Power Source keep coming up. It will not charge continuously more than a few minutes.

we tried other mobile charge units - the issue persisted. We tried different adapters - still happens. Then, we tried a regular 110v, 15A outlet and had the same issue - BUT - when trying a 110 outlet on their house (separate structure, separate panel) - everything works fine. I’ll also add that I have a Tesla wall charger at home and have also supercharged and charged off NEMA 14-50 outlets, wi5 the same mobile charger - without any problems.

So, clearly, the issue is with the garage and not with a specific outlet, either. Now that weve narrowed it down to that…we’re not sure how to further diagnose and address the issue. Everything else works perfect there, I don’t see any meaningful fluctuations in volts or amps during the charge, car sets amps to 12a when On the 110v/15a outlet and to 24a when on the 240v/30a outlet $ tried lowering those but we still experience the same issue - and I know there’s a surge protector in the panel, but they have one of the house panel as well, and I have one at home too, so don’t think that’s related.

So…what else? What should we check, look into, and try?

 

[ReddyKW]

Sounds like there could be a ground problem in the detached garage. Make sure there is a proper ground rod connected to the garage panel ground buss (ground and neutral busses must be electrically isolated in the panel).

 

[fiehlsport]

Does the garage have a subpanel fed from the main house? Something is likely not wired correctly in that area if so. I would check the feeder breaker in the main panel, and everything from there to the garage. It's possible one of the 240V legs is loose/disconnected on the way to the garage.. who knows.

 

[Odedoralive]

Does the garage have a subpanel fed from the main house? Something is likely not wired correctly in that area if so. I would check the feeder breaker in the main panel, and everything from there to the garage. It's possible one of the 240V legs is loose/disconnected on the way to the garage.. who knows.

My understanding is that the line splits from the main with the offshoots going to a panel at the house and one at the garage

 

[Odedoralive]

Sounds like there could be a ground problem in the detached garage. Make sure there is a proper ground rod connected to the garage panel ground buss (ground and neutral busses must be electrically isolated in the panel).

thanks, will definitely look at that!!

 

[fiehlsport]

My understanding is that the line splits from the main with the offshoots going to a panel at the house and one at the garage

Gotcha, sounds like the main panel is outdoors, and the house and garage are both sub-panels then.

I agree with the grounding aspect too, just odd that the vehicle or charger doesn't throw an error related to grounding. If there's no ground present, the mobile connector will usually communicate that to the car with an error code related to grounding. Maybe things have changed... not sure.

 

[TesLEEZ]

2020 NEC code requires GFCI breakers in garages now for most states, but luckily not mine. My state is still on 2017 NEC code which does not require GFCI breakers in garages.

Check if it's a GFCI breaker, that's likely your issue. Many EV chargers don't like GFCI breakers.

 

[Odedoralive]

2020 NEC code requires GFCI breakers in garages now for most states, but luckily not mine. My state is still on 2017 NEC code which does not require GFCI breakers in garages.

Check if it's a GFCI breaker, that's likely your issue. Many EV chargers don't like GFCI breakers.

Thanks, will do!

 

[Odedoralive]

2020 NEC code requires GFCI breakers in garages now for most states, but luckily not mine. My state is still on 2017 NEC code which does not require GFCI breakers in garages.

Check if it's a GFCI breaker, that's likely your issue. Many EV chargers don't like GFCI breakers.

Gotcha, sounds like the main panel is outdoors, and the house and garage are both sub-panels then.

I agree with the grounding aspect too, just odd that the vehicle or charger doesn't throw an error related to grounding. If there's no ground present, the mobile connector will usually communicate that to the car with an error code related to grounding. Maybe things have changed... not sure.

Definitely no grounding error, but will definitely look into the grounding to be sure!

 

[fiehlsport]

I would also get a cheap outlet tester for the 120V outlets and see if they check out. Just to ensure the hot/neutral/ground are wired on the correct prongs of the receptacles. Start with the easy stuff. If it really becomes a problem, an electrician can probe the panels and make sure it's wired right, everything is at 60Hz, no excessive voltage sag, etc. Throw a meter on the 240V receptacle and see if it's even 240 - if it's way low or way high, that could be an issue too.

 

[TesLEEZ]

I would also get a cheap outlet tester for the 120V outlets and see if they check out. Just to ensure the hot/neutral/ground are wired on the correct prongs of the receptacles. Start with the easy stuff. If it really becomes a problem, an electrician can probe the panels and make sure it's wired right, everything is at 60Hz, no excessive voltage sag, etc. Throw a meter on the 240V receptacle and see if it's even 240 - if it's way low or way high, that could be an issue too.

The original electrician who did the project should have done this for their final checkout before leaving the job. It's possible they didn't, but it's crazy for me to think there would be a licensed electrician out there that wouldn't do the basic final checkout before sending out the bill.

 

[fiehlsport]

The original electrician who did the project should have done this for their final checkout before leaving the job. It's possible they didn't, but it's crazy for me to think there would be a licensed electrician out there that wouldn't do the basic final checkout before sending out the bill.

Yeah, definitely sounds like a job that would have been permitted and inspected.

 

[Fidalgo]

A 30 amp breaker might be too small, (?) since my Tesla draws more than that with a 50 amp. Also agree with GFCI causing problems. Tesla advised its charger in the car has its own that can conflict with a home breaker, so I replaced mine with a regular breaker. That solved my own problem of charging interruptions.

 

[father_of_6]

A 30 amp breaker might be too small, (?) since my Tesla draws more than that with a 50 amp. Also agree with GFCI causing problems. Tesla advised its charger in the car has its own that can conflict with a home breaker, so I replaced mine with a regular breaker. That solved my own problem of charging interruptions.

The 30 amp breaker is fine... they'll just charge at 24 amps, which is plenty.

 

[Thp3]

But you need a 30 amp NEMA 14-30 adapter (EVSE? Does Tesla even sell one?). The 24 amp selection is done in the adapter. And using a NEMA 14-50 amp adapter into a 30 amp circuit should fail as you are seeing. It could be an adapter:circuit breaker mismatch when the socket is NEMA 14-50.

 

[tangible1]

My understanding is that the line splits from the main with the offshoots going to a panel at the house and one at the garage

that would imply that there are TWO METERS.
the utility must be able to monitor all usage in order to properly bill the account.

It's more likely there's a MAIN panel at the house, and the garage is on a subpanel.

 

[Odedoralive]

But you need a 30 amp NEMA 14-30 adapter (EVSE? Does Tesla even sell one?). The 24 amp selection is done in the adapter. And using a NEMA 14-50 amp adapter into a 30 amp circuit should fail as you are seeing. It could be an adapter:circuit breaker mismatch when the socket is NEMA 14-50.

To clarify - yes, Tesla makes and i am using a 14-30 adapter. There's also a 10-30 Tesla adapter (they're both part of the kit they sell) and 3rd party 6-30 adapter -- all of these work well in other locations, not this one. We tried them all, then tried replacing the adapters, then tried replacing the EVSE. It's definitely something related to the electrical setup in this location and not the equipment.

30 amp breaker + Tesla mobile charger + 30a compatible adapter/s = 24a detected and pulled by vehicle. No problems with this setup and tried it in multiple locations. This is the only one where there's an issue and there's also an issue in this same location with standard 110v/15a sockets giving the same error and interrupting the charging.

 

[Odedoralive]

that would imply that there are TWO METERS.
the utility must be able to monitor all usage in order to properly bill the account.

It's more likely there's a MAIN panel at the house, and the garage is on a subpanel.

Pretty sure the meter is on the main, the split occurs after. Not 100% sure but I believe that's what they said. It's a "Y" split if I recall correctly. Not an electrician and getting this info from my FIL who knows a thing or two, but that's all I can confirm.

 

[richguy]

To clarify - yes, Tesla makes and i am using a 14-30 adapter. There's also a 10-30 Tesla adapter (they're both part of the kit they sell) and 3rd party 6-30 adapter -- all of these work well in other locations, not this one. We tried them all, then tried replacing the adapters, then tried replacing the EVSE. It's definitely something related to the electrical setup in this location and not the equipment.

30 amp breaker + Tesla mobile charger + 30a compatible adapter/s = 24a detected and pulled by vehicle. No problems with this setup and tried it in multiple locations. This is the only one where there's an issue and there's also an issue in this same location with standard 110v/15a sockets giving the same error and interrupting the charging.

It is possible that the wires at terminals are heating up and then losing connection or partially losing connection. However, normally in the USA ground and neutral are the same and the main panel should be the only place where there is an actual, physical ground. subpanels should be connected to the main panel. The Tesla may still have a problem with the ground even if wired properly.
IMO 1. turn off power at the subpanel. 2. measure the voltages to make sure no voltage at the breakers for the outlet. 3. tighten the terminal connections.
4. close up, turn on subpanel and try again.

 

[Watts_Up]

we tried other mobile charge units - the issue persisted. We tried different adapters - still happens.
Then, we tried a regular 110v, 15A outlet and had the same issue - BUT - when trying a 110 outlet on their house
(separate structure, separate panel) - everything works fine.

Does the garage also has some 120V outlets? Which phase are they?

Is there anything else connected inside the garage to the power line?

Did you measured the volatage between each pins of your NEMA 10-30 or NEMA 14-30?

Note: If you have an extra 10-30 or 14-30 plug, I would build an extension cord with two separate NEMA 5-15 Receptacles, one on each phase.
And I would plug the TESLA UMC 5-15 plug to each receptacle to check which phase has a problem.