I've been searching the forums for info on checking to see if my BMC hub motor is bad vs. my controller or if both are possibley bad but can't seem to find the topic. I see mention of using a 9volt battery drained to 5volts to check the halls but can't find the specific post on how. I have a feeling something is blown in the motor- I hooked up a new 24-48 bmc controller, it worked but didn't "sound" right, the battery fuse blew after riding 10 feet. Now the fuse just keeps popping every time I hook it up. No way I'm buying another controller to fry before I figure out if the motor is bad, shorted or the hall sensors are bad. Any way to check the motor without having the controller hooked up? If I connect just the phase wires the fuse is ok, as soon as the halls are connected the fuse pops. The phase wires measure about 1.2 mohm between each one. Can't test the halls as usual because the fuse blows. I have dissasembled the motor for a visual inspection and everything looks good- no burnt areas at all- same for the controller. Any link or advice appreciated.
Troubleshooting bad BMC motor?
- Thread starter Tony
- Start date
Jozzer
100 kW
Sounds to me like the FET are blown in the controller.
To test hall sensors though, we usually use an oscilloscope.
Try feeding 5v through the black/red of the halls, and put a multimeter accross the black and any 1 of the 3 signal wires. Turn the motor very slowly, and you should see it alternating between 5v and 0v (or there abouts). It happens fast on a puma becuase of the gearing, so you may have to turn very slowly (never tried this with a multimeter). Then repeat using black to the other hall signal wires. Of course, if you have access to an oscilloscope, then use that instead of the multimeter!
To test hall sensors though, we usually use an oscilloscope.
Try feeding 5v through the black/red of the halls, and put a multimeter accross the black and any 1 of the 3 signal wires. Turn the motor very slowly, and you should see it alternating between 5v and 0v (or there abouts). It happens fast on a puma becuase of the gearing, so you may have to turn very slowly (never tried this with a multimeter). Then repeat using black to the other hall signal wires. Of course, if you have access to an oscilloscope, then use that instead of the multimeter!
Joey
100 W
I recently upgraded the phase and hall wires of an EVTECH BMC hub motor. When I closed it up and tested it, I discovered a problem in the hall sensors and/or wiring.
I built a BMC hubmotor hall sensor tester using fechter's schematic. It tests the hall sensors and wiring to make sure they are functioning. It worked like a charm.
-- Joey
I built a BMC hubmotor hall sensor tester using fechter's schematic. It tests the hall sensors and wiring to make sure they are functioning. It worked like a charm.
-- Joey
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