Brake resistor overheated with battery

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1

Hi everyone!
I was using a 4 Ohm (500W) resistor with a ODrive 3.6 and a power supply 48V. I worked great, but since I was producing some negative current and the psu shut down to protect itself I wanted to try with a battery. I wired a 48V battery (measured 49V with the ODrive). And I just had the time to ask the vbus when the resistance exploded, I haven’t even commanded anything. Does anyone have an idea of what could have happened?

Thank you

2

Hi @student
Exploding resistors can get pretty violent, I hope nobody was hurt.
Any chance this was running the same config you posted in the
Power supply in security mode … topic?
If the overvoltage ramp feature is enabled, it will begin dumping power into the brake resistor immediately. If the margins (start/end) were not adjusted for a 49V battery then the resistor would be at 95% duty cycle until the battery voltage dropped.