Blink charger circuit amperage

[coolfilmaker]

The EV project electricians installed our blink EV using a NEMA 6-50r receptacle. That means they would have had to put it on a circuit capable of handling 50 amps right? And that means they would have had to use a 70 amp breaker right? I'm just wondering about future upgradability and whatnot.

 

[bryan38401]

depends on you electricial code where you live a 50 amp rated device is 50 amp or less ,breaker size depends on the wire size our state electricial code makes us hard wire evse's over 120 volts so all L2s are hard wired per code most L2s are run on # 8 wire and a 40 amp breaker.

 

[planet4ever]

The EV project electricians installed our blink EV using a NEMA 6-50r receptacle. That means they would have had to put it on a circuit capable of handling 50 amps right? And that means they would have had to use a 70 amp breaker right?

Bryan is right about wire size, but you are right that a 6-50R should be installed only on a circuit capable of handling 50A. However, that means 50A breakers, not 70A. You are applying the "fudge" factor at the wrong point. A 50A circuit can support only a 40A continuous load, and the Blink EVSE should give the vehicle that number or something less. The 25% you were apparently thinking of applies if you are calculating the other way: "I want to pull 40A continuous, so I need a circuit capable of 25% more than that." Starting from the circuit amperage you say, "If I have a 50A circuit then my maximum continuous load should be 20% less than that, at most."

Why 20%? Because (1 - 0.2) * (1 + 0.25) = 1.

Ray

 

[MikeD]

1) My Blink (Model WE-30CIRE) Installation Manual specifies a circuit breaker of 40 amps (which is typical for all 30 amp EVSEs).
2) NEC 2008 Table 210.21(B)(3) "Receptacle Ratings for Various Size Circuits" reads that for a circuit rating of 40 amps the receptacle rating should be either 40 or 50 amps. (BTW I don't recall seeing any NEMA 40 amp connectors.)
3) So the NEMA 6-50R (rated 50 amps) receptacle is allowed.

As mentioned earlier, the wiring should be 8 AWG (or larger like 6 AWG) as NEC Table 310.16, etc specifies.

 

[davewill]

Yes, my Blink is also installed with a 6-50 and a 40a breaker. Unless the electrician was a total doofus, you should be able to look at the breakers and find the one labeled "EV" or some variation. It's a good idea to know where the breaker is, anyway. You might find yourself wanting to reset it in the middle of the night, some time.

 

[TonyWilliams]

Yes, my Blink is also installed with a 6-50 and a 40a breaker. Unless the electrician was a total doofus, you should be able to look at the breakers and find the one labeled "EV" or some variation. It's a good idea to know where the breaker is, anyway. You might find yourself wanting to reset it in the middle of the night, some time.

I don't think code will allow a 40 amp breaker on a 50 amp receptacle. Edit: I just walked out and looked in the breaker box, and sure enough, it's a 40 amp breaker where the Blink had been. I've had it pumping 40 amps into my Rav4 for about two weeks !!!

I guess I'll wander over to Home Depot and get a new breaker:

$8.54 - In stock
Common trip, thermal magnetic; 2 pole; 120/240 VAC at 50/60 Hz (uL/CSA); 50 Ampere

 

[DaveEV]

I don't think code will allow a 40 amp breaker on a 50 amp receptacle.

As MikeD said above, NEC is perfectly OK w/a 50A receptacle on a 40A circuit.

I guess I'll wander over to Home Depot and get a new breaker:

Make sure your wire is up to the task of handling 50A instead of 40A...

 

[MikeD]

For long cable lengths, voltage drop starts to become a problem that has to be taken into account. But if your cable is no longer than, say 100 feet, in all the following: For a 40 amp circuit (requiring 50 amp circuit breaker), #8 is thick enough. Looking at somewhat more powerful future on-board chargers, for a 48 amp circuit (requiring 60 amp circuit breaker), #6 is thick enough. And (as far as I want to go -- imagine one's house needing 2 of these for 2 EVs!) for a 56 amp circuit (requiring 70 amp circuit breaker), #4 is thick enough.

If you anticipate needing to go beyond #8 in the foreseeable future, it probably makes financial sense to use the anticipated thicker gauge when doing initial/next wiring.

If any of this appears mistaken, please correct me -- I don't do this for a living.

 

[DaveEV]

A wire's rated ampacity is dependent on a number of factors and wire gauge and length are only two factors.

The temperature rating and installation specifics are also primary factors.

 

[TonyWilliams]

for a 56 amp circuit (requiring 70 amp circuit breaker), #4 is thick enough.

The Tesla Roadster has been pulling 70 amps for years now, and the Model S can pull 80 amps (needs 100 amp breaker).

I recommend #3 wire for shorter runs, and #2 for those longer ones. Obviously, a licensed professional is best to recommend the actual needs of your EVSE wiring.