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Can I install charger on an existing 70amp breaker?

tomnouri

New Member
Aug 17, 2021
4
0
California
So I’ve installed new 60amp breakers and all work flawlessly. An existing breaker in an old panel is 70amps. Wiring gauge etc all in good order. Wondering if 70amps is ok on mobile charger with adapter on 240v. Thank u
 

jmaddr

Active Member
Mar 29, 2019
1,016
1,033
Florida
No, to follow on @mikemarmar, per code in just about every area, the breaker has to match the outlet and wiring. A higher breaker could submit the breaker and wiring to excessive current, warming or burning the wires/outlet with a threat of fire and equipment damage. Technically in some locations you can go smaller but it’s a dumb choice. You would need to mark the outlet with a lower A rating stating the breaker size so a person wouldn’t plug-in something that constantly trips the undersized breaker.
 

tomnouri

New Member
Aug 17, 2021
4
0
California
It’s 14-50, and I know many including myself install that on 60amp breakers with no issues as it’s whats locally readily available. So if 60 is ok why not 70? Will check entire circuit and wiring for heat etc… just looking for proper explanation, not just refer to label.
 

brkaus

Well-Known Member
Jul 8, 2014
8,081
6,644
Austin, TX
Problem is the outlet is rated for 50a. Something bad happens and it pulls 60 (or 70) for a while the outlet may fail (burn) and the circuit breaker wouldn’t do anything.

Sure, it will work, if providing power to the outlet is the definition of working. But it will not provide the intended safety function in the unlikely event that it is needed.
 
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mikemarmar

Member
Jun 2, 2021
10
7
Salt Lake City
The contacts in the outlet itself are only rated to 50A, so you need to put a 50A breaker on it. Yes you can get away with a larger breaker, but if something goes wrong with the outlet you could end up with a fire or a melted outlet.
 

tomnouri

New Member
Aug 17, 2021
4
0
California
Thank u for all ur replies really appreciate it 😘. So it seems like the outlet is the limiting factor. Where do u guys get 14 - 60 or 70 outlets from?
 

jcanoe

Active Member
Oct 2, 2020
3,429
3,483
Maryland
Thank u for all ur replies really appreciate it 😘. So it seems like the outlet is the limiting factor. Where do u guys get 14 - 60 or 70 outlets from?
In almost every case Level 2 (240V) charging an EV at over 50A requires a hard wired installation, i.e. no outlet. I recall reading that there was one manufacturer of EVSE that offered a NEMA 14-60 plug but I have not seen anything more about this. None of the major manufacturers of EVSE support more than a 14-50 or 6-50 50A receptacle. Higher amperage EVSE, i.e. 60A and 80A are always hard wired.

The Gen1/Gen2 Tesla HPWC are capable of charging at up to 80A on a 100A circuit. The current Gen3 Wall Connector is limited to 48A on a 60A circuit.
 

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