question about charging at 110V/120V on 15A

[jhams]

Hello All,

I have a question about charging at 110V on my 15A breaker. Is there a smart way to handle the current draw? By default the car is set to maximum power draw can you can turn the current limit down and then plug in your UMC. Sometimes for whatever reason it decides to reset back to high current which trips the breaker.

Example: I have a model Y. I can set it to 10A then plug in my UMC and everything seems fine. It seems to remember where based upon GPS (Knows where my home is).

Example 2: I have a model S loaner vehicle, I went to set it to 10A then plug in UMC but it kept resetting and tripping my breaker. This happened 6-8x before the 10A limit decided to remain.

Is there a reason example 2 doesn't remain at 10A when I set the charging limit? Is there a proper order of operations?

 

[Saghost]

Both cars should remember that you manually reduced the current at that location and should respect it.

The breaker shouldn’t be tripping at 12A, either. Is there something else on the circuit with the car?

 

[jhams]

Both cars should remember that you manually reduced the current at that location and should respect it.

The breaker shouldn’t be tripping at 12A, either. Is there something else on the circuit with the car?

Yeah I have quite a few things on it (temporary setup) so I usually try to set it at 8A to start. It can usually handle about 10 with the other loads.

With the model S loaner, I would set it to 8A or 10A then plug in the connector and it would change from blue to green and breaker would flip. Then I go back to check the car and it resets to max current. Any idea?

 

[Saghost]

Yeah I have quite a few things on it (temporary setup) so I usually try to set it at 8A to start. It can usually handle about 10 with the other loads.

With the model S loaner, I would set it to 8A or 10A then plug in the connector and it would change from blue to green and breaker would flip. Then I go back to check the car and it resets to max current. Any idea?

The UMC tells the car a maximum amperage based on the plug attached, which is what the car initially defaults to. I’m thinking the car may not let you turn it down until it sees that it is plugged in?

Try turning off or unplugging everything else for a bit, plugging the car in, starting charging, then turn the car down and then plug the rest in?

Really it’d be much wiser to find a circuit for the car with nothing else on it, even if you have to use an extension cord to get there.

 

[user212_nr]

Yeah I have quite a few things on it (temporary setup) so I usually try to set it at 8A to start. It can usually handle about 10 with the other loads.

I am disinclined to help you in any way, other than to tell you that you should never charge a Tesla on any circuit that is shared with any other non-trivial appliance. A garage door opener is the only reasonable exception that I know about.

There is no way that you live in a house where there is only one 120v circuit breaker. Here is a nice, heavy duty, 50 foot extension cord that you can use to safely charge or power your other appliances from a different circuit.

https://www.amazon.com/Foot-Lighted-Outdoor-Extension-Cord/dp/B078KDZBBX

 

[Rocky_H]

can you can turn the current limit down and then plug in your UMC

I can set it to 10A then plug in my UMC

I went to set it to 10A then plug in UMC

So you're always doing it in that order, and it's not working.

Is there a proper order of operations?

Yes--the opposite of that.
It will program a certain amp limit tagged on a certain GPS location, if you set it to that while it is plugged in. So that's fine if you change things around before, but it's not going to remember that setting. When you do have it plugged in, though, then change the amp setting, and that will make it create a memory entry for that location.