What about 480VAC charging?

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gpsman

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Oct 20, 2016
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What if I have convieniently placed 480 VAC power outlets? (4 wire 3 phase) Is this helpful for charging? How would I attach this to a Bolt EV?
 
I believe you could install L3 fast charging if you have 480VAC with enough power. However, an L3 station is probably more expensive than you would be willing to spend. Also, I wouldn't think you could get one with a plug, only hard wired.
 
If you didn't want to go the L3 route then you'll be limited to 240V charging, which (and here I must warn you that I'm not an electrician) I imagine you could tap off one of the 480V phases.
 
SeanNelson said:
If you didn't want to go the L3 route then you'll be limited to 240V charging, which (and here I must warn you that I'm not an electrician) I imagine you could tap off one of the 480V phases.
No. A 4 wire 480V system is presumably a wye system, so the neutral to phase voltage is 277V. If the Bolt charger and the J1772 standard are rated for 277V, then you could charge using one phase conductor and one neutral. [I don't know about either of those questions.] Otherwise, you'd need a transformer.

Cheers, Wayne
 
gpsman said:
What if I have convieniently placed 480 VAC power outlets? (4 wire 3 phase) Is this helpful for charging? How would I attach this to a Bolt EV?

Only way to do this would be to somehow get the power down from 480VAC to 208VAC or 240VAC and then wire up a standard L2 EVSE. Apparently you need a transformer of some sort to do that. Just tapping off of one of the hot wires won't work. I don't think the J1772 spec even covers 277VAC.
 
I was reading about the wye connection and the 277 VAC one leg to ground.

I am mostly wondering is 277 V is "close enough" for a 240 VAC EVSE.

I'm thinking about how many consumer electronics (low power - shavers, etc - for international travel) work on multiple voltages.
 
gpsman said:
I was reading about the wye connection and the 277 VAC one leg to ground.

I am mostly wondering is 277 V is "close enough" for a 240 VAC EVSE.

I'm thinking about how many consumer electronics (low power - shavers, etc - for international travel) work on multiple voltages.
The EVSE is just a very smart circuit breaker. It doesn't do any stepping down or up of voltage. It just advertises to the car how amperage it can supply and waits for the car to signal it to start suppling electricity. Unless the car's internal charger is capable of accepting 277VAC, you do not want to hookup that much voltage to it because of the risk of frying the charger and/or starting a fire in the car. Even Teslas aren't capable of 277VAC. They max out at 265.
 
In the US.
Residential get 120/240 single phase.
Commercial get 120/208 3 phase (wye)
Industry gets 277/480v 3 phase (wye) and up. The office gets power by stepping down the power, with a transformer. 277/480v -> 120/208v (wye).

There is no receptacle that will handle 277v.

We use a special receptacle for welding machine and power washers. Type, "Appleton plug" on Google for image.
 
What I have at work is also used for welding machines and bench testing up to 10hp motors.

30 Amps - Voltage 480VAC - Number of Poles 3 - Number of Wires 4 - L16-30R NEMA Configuration - Phase 3 - HP 10.0

Also called "Bryant" plug & recepticle.
 
gpsman said:
30 Amps - Voltage 480VAC - Number of Poles 3 - Number of Wires 4 - L16-30R NEMA Configuration - Phase 3 - HP 10.0
Ah, NEMA L16 doesn't provide a neutral, it's 3 phase conductors plus ground. So the only voltage available is 480V, there's no chance of hooking up an EVSE directly. You'd need to add a transformer to drop the voltage from 480V to 240V to use that receptacle.

Cheers, Wayne
 
If you have $7000 to blow, Bosch makes a 24KW rig that will do the trick. I think somebody also makes puny little 10KW rigs too, but sort of silly considering that the Bolt charges at 7+ KW out of the J-plug.

https://www.chargepoint.com/files/BMW_i_DC_fast_charger_datasheet.pdf

Compared to the "Big" 50 KW chargers, the cords on these seem scrawny.
 
wwhitney said:
gpsman said:
30 Amps - Voltage 480VAC - Number of Poles 3 - Number of Wires 4 - L16-30R NEMA Configuration - Phase 3 - HP 10.0
Ah, NEMA L16 doesn't provide a neutral, it's 3 phase conductors plus ground. So the only voltage available is 480V, there's no chance of hooking up an EVSE directly. You'd need to add a transformer to drop the voltage from 480V to 240V to use that receptacle.

Cheers, Wayne

Ah ha! That explains a lot.

Interestingly I found a 480 VAC to 240 VAC 10 kw transformer for $299.

However; it weighs 125 lbs. and is 2000 miles from me. It is for outdoors and is industrial grade. A lot of work for a few L2 charges the few times a year I would need it.

Generally I work long hours and have a 30 minute commute. Generally speaking the hours I work (12) will recoup the miles I drive each day with L1 charging. The exception would be if I run the car near empty over the weekend and need a long drive Monday.
 
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