openinverter forum

I now have the O/I board installed in the SDU and I am setting up the test bed.
I have searched for the value of resistor to use for current limiting on the motor battery B+ (for test purposes only) and can only find "use a resistor or some heater wire". I understand that it is critical NOT to use a fuse as the B+ going open circuit while the motor is spinning will destroy things. This seems to preclude using a light-bulb as the current limiter.
What value / size resistor to use for this? I am going to use four 12 volt 100aH batteries (48 volt) in series for testing.
Thanks!

It's really just for first-plug-in-hope-I-haven't-got-any-wires-crossed testing A lightbulb would be fine (and gives a good 'readout' of current passing), then remove it when you start spinning the motor at any speed.

I used an old clothes iron heating element. Damien would propose a cooking stove element.

That makes sense, I will use a light-bulb (120 volt 100 watt)
Any recommendations on the pre-charge resistor value? I see posts of people using anything from 25 to 100 ohms
I just happen to have a 35 ohm 100 watt lying around...

That'll do just fine. A larger value resistor will give a slower precharge, that's all