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Discussion Starter · #1 ·
The breaker marked below keeps tripping since the breaker is shared between my garage and my extended living room.
I noticed that when the living room a/c is running the charging fails almost immediately but with the living room almost off I'm good to use the charger in my garage at a full 20 amps. Unfortunately I don't know what the size of the breaker is that is markeds below.

My garage has a 20amp sub panel and it's not powerful enough to let me use the full 16 useable amps to charge the car and it's also inadequately slow to charge at 15amps.

I have 2 questions, Can I tap into the 30amp breaker which runs to the outside of the house via 30amp disconnect my electrician installed and run thick 8 gauge romex wire and run it to the garage just to power the charger ?


Also is there any room on this box to split up the garage and the extended living room so that they aren't sharing the same load ?



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I believe it is time to do a load calculation on your service.
You will be very disappointed in charging your electric rocket car at 120v.

NO you may not use a 30 amp breaker for a 20 outlet. The NEC has rules against that.
The garage outlet should be on its own circuit or shared with other outside outlets.
If you have a 20 amp panel why is it not strong eough for a 20 amp load?
 

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Discussion Starter · #4 ·
I believe it is time to do a load calculation on your service.
You will be very disappointed in charging your electric rocket car at 120v.

NO you may not use a 30 amp breaker for a 20 outlet. The NEC has rules against that.

The garage outlet should be on its own circuit or shared with other outside outlets.
If you have a 20 amp panel why is it not strong eough for a 20 amp load?
In the tesla app, I can pull a max of 16 amps which was okay in the beginning. I was able to charge twice overnight at a rate of about 13 miles per hour. But now when I try to do 16 amps it fails after 1 hour forcing me to reduce it to 15 amps to charge stable overnight without failures. But I need more power / faster charging. I can't sit here for 18 hours+.

Also in the subpanel I'm using a double pole 20amp breaker for 240 volts.
 

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Discussion Starter · #5 ·
what is this 30 amp circuit powering presently?
split ac, but my intention is that I'll just piggyback off this and wire directly to the garage car charger.
So when I'm charging I'll be sure the split ac isn't turned on otherwise the breaker would trip.

I also had thoughts of replacing the 30amp with a 40amp to get more power to garage
 

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If you want faster charging then you need A LOT MORE AMPS. Like 100amps for the super charger Tesla talks about. Even a 50 amp charger is will not reduce the charge time to 9 hours. More like 12 hours. Your need an electrician and a 100 amp circuit for your car. Then MAYBE you can get charging into single digit hours.
 

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Let me try to understand this. Correct me if I'm wrong. You do NOT have a Power Wall.
You have a Tesla Wall Connector that you use to charge a Tesla electric car.
You have 100A service to the house.
You want a Tesla charging rate which is not useless.
OK, I think I can work with that.

The first thing I need to know is: Can you name TWO 120V circuits in there, that you don't heavily load while you're EV charging, and that are 20A breaker? Alternately that are 15 amps but I'd prefer 20. We're gonna do magic.

Also where is your main breaker? Is there a breaker out at the meter? Can you get us photos of all your electrical breaker panels?

I assume you want to work out of this panel. How comfortable are you about pulling the deadfront cover off that panel, getting a nice bright flashlight and taking some pix of the wiring currently in there?







If you want faster charging then you need A LOT MORE AMPS. Like 100amps for the super charger Tesla talks about.
I appreciate your commentary generally but this one is a widely perpetuated falsehood that deters EV adoption, though it isn't your fault for repeating. But it's still wrong. Here. Alec says it better than me at 34:43.


Go to 28:12 for more on that.

For those rare exceptions #1 who cares, you'll catch back up over several days. You don't fill your gas car every night, do you? And #2 if your tomorrow will also be very busy and you really need to top up, you stop at a Supercharger on the way home for 5-10 minutes (really). Thus, you are fast-charging in the middle of capacity (20-80%) where it's full speed and most efficient. At 60-70% (based on your experience) you go home and slow charge to 100%, which is better for the battery anyway.
 
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