Charger startup sequence – the measurements
This is a companion to the previous post. All measurements are done by SpeakEV user ElectricBeagle. They are all done using either a granny cable set to 10 amps or a decent chargepoint set to 30 amps.
Here is the current when plugging in, measured using a current coil on the L wire. It doesn’t show the phase angle but all current is reactive as it’s created by the filter capacitors.The stable, reactive current is about 6A RMS, close to 10A peak. Note that the spike occurs when the reactive current would be about zero, so the actual plug voltage would be at it’s maximum, creating the maximum spike current. It’s roughly 40 amps and lasts about 1 ms. Note charging has not started yet.
Ignore the lower curve. The upper trace is measured using a resistor in the PE wire. You can clearly see the two measurement pulses. They are roughly 20 mA and last 1ms. These are to measure earth resistance; the car injects the measurement current between N and PE. This happens after plugging in but before charging starts.
This is a slow trace of the L current, measured again using the current coil. It shows the spike and reactive current. After about 3 seconds the charger kicks in and does gradual current ramp up to about 13A lead current. That is about 12A real current.