EVSE upgrage - advantages to 12A?

[billvon]

I have one EVSE-upgrade cable that has both the 240V and 16A mods. (It actually seems to draw about 17A when in use.)

I plan on sending the other EVSE I have (trickle charger that came with the car) to EVSE-upgrade to have it upgraded as well. Are there any advantages in leaving it at 12A? I can see some cases where you might be able to do the two-outlet 240V trick but a 17A draw would be likely to trip a breaker on two 'standard' 120V circuits. (And of course GFI protected outlets won't work with any two-outlet connection.) On the other hand any dedicated 20A 240V outlet will let me use the higher current version. Anyone have any experience with which is more available?

 

[foobert]

Any relatively "modern" wiring should be using 12AWG (or better) wire and a 20 amp breaker to outlets. My 40 year old house does so. But, this is not guaranteed. It is allowable in present electrical code to use 15 amp circuits for outlets (with a few exceptions for the kitchen, etc).

 

[ebill3]

I have one EVSE-upgrade cable that has both the 240V and 16A mods. (It actually seems to draw about 17A when in use.)

I plan on sending the other EVSE I have (trickle charger that came with the car) to EVSE-upgrade to have it upgraded as well. Are there any advantages in leaving it at 12A? I can see some cases where you might be able to do the two-outlet 240V trick but a 17A draw would be likely to trip a breaker on two 'standard' 120V circuits. (And of course GFI protected outlets won't work with any two-outlet connection.) On the other hand any dedicated 20A 240V outlet will let me use the higher current version. Anyone have any experience with which is more available?

Assuming the second unit will be your traveling EVSE, I recommend you leave it at 12 Amps.

While maybe any reasonably modern home should have 12 AWG wiring and 20 Amp breakers, it is far from a given that they do. I live in a rental complex, probably about 15 years old. Best I can tell, with the exception of the ktchen and the washer, all circuits are 14 AWG and 15 Amps. And, of course, those 20 Amp kitchen circuits are not available for quick 240 use as they are GFCI protected.

I use a quick 240 at a location I frequently visit, and one leg I use has a freezer and a drink vending machine on it. I doubt it would allow another 16 or 17 Amps, but 12 Amps works just fine.

Bill

 

[smkettner]

I believe most 240v circuits are 20a or better. It will be rare to find a 15a 240v circuit.
12a would work on the quick 240 adapter... although plenty report V2 also works fine on 15a breakers. Not sure I would trust that for long term use.

I went with 12a and it is fine for me even if a bit slower than 16a. I don't use it full time.

 

[DaveEV]

I believe most 240v circuits are 20a or better. It will be rare to find a 15a 240v circuit.
12a would work on the quick 240 adapter... although plenty report V2 also works fine on 15a breakers. Not sure I would trust that for long term use.

16A on a 15A circuit is not guaranteed to trip the circuit breaker even after an infinite amount of time. If you look at the trip curves of circuit breakers spec is typically between 1.0x-1.3x breaker rating (or 15-20A on a 15A circuit) before it's guaranteed to trip after thousands of seconds.

It's not hard to put a circuit under that sort of load - two portable space heaters could potentially put 20A on a 15A circuit for hours and it might not trip. Or it might trip in a under a minute. Both scenarios would be under spec.

I certainly would not make regular use of 16A on a 15A circuit unless I knew the runs were short. But for a couple hours on circuits that are otherwise unused, you should be fine. Never a bad idea to check the voltage drop, too!

 

[ebill3]

I certainly would make regular use of 16A on a 15A circuit. But for a couple hours on circuits that are otherwise unused, you should be fine. Never a bad idea to check the voltage drop, too!

Did you mean to include a "not" between "would" and "make"?

I have two upgraded Nissan EVSEs, both at 12 Amps. I went through a few email exchanges with Phil's associate to convince him I really wanted 12 Amps, not 16. I just would not be comfortable using a 16 Amp unit on two 120 volt 14 AWG 15 Amp circuits.

Bill

 

[DaveEV]

Did you mean to include a "not" between "would" and "make"?

Whoops, fixed that.

I have two upgraded Nissan EVSEs, both at 12 Amps. I went through a few email exchanges with Phil's associate to convince him I really wanted 12 Amps, not 16. I just would not be comfortable using a 16 Amp unit on two 120 volt 14 AWG 15 Amp circuits.

I did the same thing. I did some testing of mine on 15A circuits - all seemed well during my short tests. I would really love to integrate a small digital voltmeter into my Easy240. Bonus points for measuring each split-phase leg. Hmm, something like this would work. Even have the choice of using either 1 or 2 to measure each leg or both. http://r.ebay.com/ef201M" onclick="window.open(this.href);return false;

 

[billvon]

Thanks for the opinions. I'll probably keep the second one at 12A.