EV Chargers Service Size

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dvcraven0522

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Service size for 10 car chargers:

EV charger 19.2KW @ 208V

1 charger = 19.2 x 1.25 - 24kw
2-9 chargers = 19.2 x 9 = 172.8kw

24kw + 172.8kw = 196.8kw/.36 = 546 amps

225kw xfmr. 208/3 = 625 ampere.

Anyone have a problem with that. Thx!
 
dvcraven0522 said:
Service size for 10 car chargers:

EV charger 19.2KW @ 208V
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You're not going to find any such EVSE. You can find an 80A EVSE, which will be 19.2 kW if supplied by 240V. But at 208V it will be only 16.6 kW.

So your line current for (3) of them wired as a delta will be 80A * sqrt(3) = 138.6A. With 3 sets of those, plus one more, your two highest line currents if all were running flat out would be 3 * 138.6 + 80 = 496A continuous.

In practice, you'll never see that as cars that can charge at 80A AC are very rare, and so you'll never get 10 of them at once. [That could change in 10 or 20 years, depending on how the EV market develops.] You could get 10 at once that charge at 40A, so you might actually see half that. 10 @ 30A each is quite likely (assuming you ever get 10 cars).

EVSEs that talk to each other and have a group load management capability would be a good option. You could set it to cap the line currents at 200A continuous, and I bet you'd seldom or never hit the cap. Or at the very minimum for economizing, put in 3 at 80A, and cap the other 7 at 40A.

Cheers, Wayne
 
Barbqranch said:
Where does the 19.2 KW come from? I though most of them were 10KW or less.
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As Wayne stated there are 80 amp tesla units. I have only wired one of those but it can be configured to be set at 60 amp or even lower just by moving a jumper. Some are done by phone.
 
Dennis Alwon said:
As Wayne stated there are 80 amp tesla units. I have only wired one of those but it can be configured to be set at 60 amp or even lower just by moving a jumper. Some are done by phone.
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To expand on that, the jumper setting will set the high limit. You can dial it down from there by phone app, but not above it.
 
retirede said:
To expand on that, the jumper setting will set the high limit. You can dial it down from there by phone app, but not above it.
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But are you dialing down the EVSE for any car that uses it, or just dialing down what you car will use? If the latter, that has no effect on this discussion.

Cheers, Wayne
 
wwhitney said:
But are you dialing down the EVSE for any car that uses it, or just dialing down what you car will use? If the latter, that has no effect on this discussion.

Cheers, Wayne
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Not sure what retirede is looking at but the one I did was just a jumper that will change the load of the unit. I know other units can be controlled by phone but I believe it is as you stated dialing it down

I think this is the one I wired


page 5
 
Dennis Alwon said:
Not sure what retirede is looking at but the one I did was just a jumper that will change the load of the unit. I know other units can be controlled by phone but I believe it is as you stated dialing it down

I think this is the one I wired


page 5
Click to expand...

Grizzl-E Smart Chargers have the max current set by DIP switches, but can be throttled back in their app.
 
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