EVDRIVER said:
Randy said:
It's been bugging me, and I haven't done any measuring, but we have a ChargePoint unit at work that is connected to 208v. The digital display says it is delivering 3,653 watts when charging my LEAF...That has to be a higher current than 16 amps if the display is correct...
Because that unit does not have a 16A pilot signal so it can go higher. The pilot signal of the EVSE always determines the max amp draw the charger is allowed, it will not increase past that figure regardless of the voltage.
Just to further clarify:
1) At voltages around 120V, the on-board charger will not draw more than 12 amps, regardless of the pilot signal from the EVSE.
2) At higher voltages (I do not know where the change-over occurs), the OBC will attempt to get 3,840 watts (240 volts x 16 amps) and will vary the current depending on the actual voltage:
2a) At higher voltages, up to the limit (250 volts, I think Phil said), the OBC will draw less current.
2b) At lower voltages, the OBC will draw more current up to some limit, which is at least 18 amps but might be a little bit more.
IN ANY CASE, the OBC will never draw more current than is allowed by the EVSE pilot signal!
BTW, in general, if you apply too much voltage to a circuit, you have problems with arcing and component/insulation breakdown.
On the other hand, if too much current flows, things tend to heat up and, if they get hot enough, burn up. The main difference between a 20 amp household circuit and a 40 amp circuit, other than the circuit breaker, is the diameter of the wires. The purpose of a circuit breaker (over current protection device) is to prevent so much current from flowing that the wires will burn up and start a fire.