Blown Focbox .. ( was Help diagnose cutouts. Dual focbox | can bus | 6384 maytech/lacroix motors | flipshit vx1 | metr logs )

How-Tos & Esk8 mechanics Esk8 Mechanics
20

so the focbox is foc’d.

question is what caused it? what to do next so I don’t blow another one in it’s place?

  1. With the motor disconnected it spins smoothly. doing the hand tests of shorting phases together it seems to behave as expected.

  2. Plugging any two phase leads from the motor into any phase connectors on the focbox and they drag as if shorted.

  3. testing continuity on the phase connectors on the focbox shows two wires full continuity. between either of the first two and the third wire the other two seem to be charging a capacitor. current flows for a moment. then if i reverse the probes it flows again. on a spare focbox there’s none of this.

  4. The power leads to the focbox also are shorted / have continuity continuously. by contrast on a spare focbox. you get the filling a capacitor effect.

This suggests to me the focbox is foc’d

I think the hand tests of the motor suggest it wasn’t the issue. but how can I be sure? Next I will extract the focbox and open it up see what I can see… what should I see? how can I get to root cause so I don’t blow another one?

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