Justwin 750 Watt Brushless Motor - troubleshooting

[RobertMDM]

Hey guys,

I recently repaired the sprag clutch on my Belize Bike / Justwin Cool E Rider.

You can see that thread here http://endless-sphere.com/forums/viewtopic.php?f=2&t=62008

I was riding it around for about an hour the other day and at the very end of the ride, the motor simply stopped working.
When I reached the last block to my house, the pedal assist wouldn't kick in when pedaling and the throttle wouldn't make the motor do anything either.
There was no noise, or smoke, or any indication of something going wrong.

I'm now trying to trouble shoot what's wrong with it. Maybe i shorted something?

I recharged the batteries.
I hit the button on the circuit breaker (i can't recall if it was tripped or not)
All lights and accessories receive power and are working normally.

Correct me if i'm wrong here:
The controller has 3 phase wires, and then the 5 tiny multicolored wires bundled together are the hall sensors?

I turned the power on and connected a multimeter to the hall sensors (from the controller)
from the black wire to the other colors (Y, G, B): all read -86 V
Black to Red = 0 V

Does this mean anything?

How can i test the phase wires?

Is there a link to any kind of trouble shooting guide for a brushless DC motor like mine? I only seem to find Hub motor troubleshooting tutorials

 

[Deleted member 4366]

It means something is terribly wrong!. hopefully, it's the use of the meter. Did you set it to AC or DC?

You should have 5v between the black and red. You then should check between the black and each of the three others whilst rotating the wheel backwards. You should see 5v switching on and off.

If you don't get 5v between the red and black, check between the red and black throttle wires. If still no 5v, then your controller is in standby mode or blown. Do you have an ignition wire. If so, that's where your problem would be.

 

[mfj197]

It's reading 86 millivolts, not volts. Just as well, otherwise there's quite a good shock right there!

Michael

 

[RobertMDM]

You should have 5v between the black and red. You then should check between the black and each of the three others whilst rotating the wheel backwards. You should see 5v switching on and off.

If you don't get 5v between the red and black, check between the red and black throttle wires. If still no 5v, then your controller is in standby mode or blown. Do you have an ignition wire. If so, that's where your problem would be.

Hey d8veh, This motor isn't a hub motor, so i'm not sure what to do when you say to rotate the wheel. Please see the image above, it's a motor mounted to the back of the trike. Is there something else i can do? Should it change when i pedal?

 

[Deleted member 4366]

To test the halls, the motor has to rotate very slowly. It doesn't matter how you do it, but, obviously, if it has a clutch, rotating it forward won't be much help.

 

[RobertMDM]

Originally, I didn't have the controller hall cable plugged into the motor hall cable.

Then i followed this guide:
https://www.ebikes.ca/documents/HallSensorTestingFinal.pdf

These are the readings that i get:
Black to Yellow: 7.73 V
Black to Green: 7.73 V
Black to Blue: 7.73 V
Black to Red: 7.73V

Red to Yellow: 0 V
Red to Green: 0 V
Red to Blue: 0 V

When i rotate one of the back wheels of the trike, which then rotates the motor, I don't get any change in the voltage readings at all for any of the above mentioned combinations.

What does this possibly mean?

 

[Deleted member 4366]

Everything on the 5v rail should be regulated to approximately 5v, so it's not normally possible to get 7.73v on it. This test should give a clue to what's going on:

Measure between the black and red throttle wires, and then do it again with the motor disconnected.