DBC
Well-Known Member
- First Name
- Don
- Joined
- Oct 1, 2020
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- 8
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- Location
- San Diego
- Vehicles
- Volt ELR
If you aren't going to use the charger that comes with the MME you will likely have to hardwire it. The national code now requires a GFCI breaker on the circuit if you are using a 6-50 or 14-50 outlet. Since the EVSE already has a GFCI, and since two GFCI with different sensitivities on the same circuit can result in unwanted tripping, you'll want to hardwire it. Of course state codes lag the national code, and then there are local codes, so this may not be required where you are. Note that even if it does, the MME charger apparently will work with a GFCI breaker, so you could use a 6-50 or 14-50 outlet with this charger.
I would not bother with charging above 30A. The more amps the less efficient the charging, and 30A will get you about 20 miles an hour. Given cars usually sit for 10 hours a day, and given your commute is 300 miles a week, 30A will give you enough charging and then some. (Also note that buying an EVSE which supports higher charging than you need isn't that wise. EVSE won't last forever, so buying more EVSE than you need is like buying a pair of pants for you son that he'll need if five years.)
Note there are three parts of the circuit. The outlet, the wire, and the breaker. These do not have to match. Since outlets and breakers are easy to change but wire isn't, if you are going to "future-proof" the circuit, concentrate on the wire. However, I wouldn't bother to run #2 copper wire. It would be large and expensive and total overkill. I'd run #6 which would support 40A at about any expected temperature.
Also note that while the saying is "the breaker protects the wire", the breaker also protects the EVSE. Given the wire will be more robust than the EVSE, the breaker should match the EVSE.
I would not bother with charging above 30A. The more amps the less efficient the charging, and 30A will get you about 20 miles an hour. Given cars usually sit for 10 hours a day, and given your commute is 300 miles a week, 30A will give you enough charging and then some. (Also note that buying an EVSE which supports higher charging than you need isn't that wise. EVSE won't last forever, so buying more EVSE than you need is like buying a pair of pants for you son that he'll need if five years.)
Note there are three parts of the circuit. The outlet, the wire, and the breaker. These do not have to match. Since outlets and breakers are easy to change but wire isn't, if you are going to "future-proof" the circuit, concentrate on the wire. However, I wouldn't bother to run #2 copper wire. It would be large and expensive and total overkill. I'd run #6 which would support 40A at about any expected temperature.
Also note that while the saying is "the breaker protects the wire", the breaker also protects the EVSE. Given the wire will be more robust than the EVSE, the breaker should match the EVSE.
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