hub motor running jerky and going backwards and forwards

Hi guys, noob question here again - my 1kW 48V hub motor has started stuttering badly violently driving forward and backwards (!) in short jerky motions with gaps of no drive as I push my trike along the ground.

A few years ago I replaced the Hall sensors in the hub and now some of the Hall sensor control wires near the controller look like they might be a little damaged. The Anderson plug on the green power wire to the Hub motor is also showing a bit of heat damage.

The speedometer/odometer feature of my Cycle Analyst stopped working quite a while back after a big spark occurred when connecting the controller to the battery, but the rest of the CA seems to work fine. (I since got a big red cut-off switch to allow spark free connection/disconnection)

The hub motor got very hot to the touch going uphill and started cutting out until I let it cool before riding on a few times not long before things went bad.

Controller is a C7240-NC 40A Grinfineon Controller with a Cycle Analyst CA3-DP and 20Ah 48V (52V?) Ping battery.

Would you guys suspect wire damage or poor contact on the green wire or motor issues or a damaged controller? I'm at a bit of a loss as to what to fix/replace first!

Thanks!

-Martin Hill

Hall sensor signals are needed for the controller to properly commutate the motor. The effects you describe all relate to improper commutation. Fix everything you can see on the wiring before applying power again. Verify the hall signals by rotating the wheel and measuring them without applying any throttle. They should switch cleanly between zero and approximately 5 volts. Then try the controller gently to see if it is damaged. Don't operate the controller with suspected bad wiring at all.

Alan B said:

Hall sensor signals are needed for the controller to properly commutate the motor. The effects you describe all relate to improper commutation. Fix everything you can see on the wiring before applying power again. Verify the hall signals by rotating the wheel and measuring them without applying any throttle. They should switch cleanly between zero and approximately 5 volts. Then try the controller gently to see if it is damaged. Don't operate the controller with suspected bad wiring at all.

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Thanks for the succinct suggestions Alan. I'll target the wiring harness first and see how it goes. Here's hoping I haven't cooked my controller!

Frakentrike said:

...now some of the Hall sensor control wires near the controller look like they might be a little damaged.

Click to expand...

It's worth pointing out that the CA speed connection to the controller uses a hall signal from the motor. The controller/motor rotation issue also could play to halls, so there is a somewhat common theme arising...

I would fix the phase wire first, as it's really easy, and my bike started doing a bit of shuddering before I noticed the Anderson's had deformed just enough over time from slow overheating to be making bad contact, so it might fix things without ripping things apart too much.
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