Hub motor doesn't run after motorcable replacement

mhoch3

1 µW
Joined
Aug 22, 2022
Messages
2
Hello everyone,

I had a crash with my ebike which dameged the motorcable going into the hub motor. One of the cable got broken but when bending the damaged part the motor sometimes run again. Now i replaced the whole cable cord (8 cables inside) but all the motor does is a stalling sound when using the throttle.

Anyone nows what's the problem?
 
mhoch3 said:
I had a crash with my ebike which dameged the motorcable going into the hub motor. One of the cable got broken but when bending the damaged part the motor sometimes run again. Now i replaced the whole cable cord (8 cables inside) but all the motor does is a stalling sound when using the throttle.

Anyone nows what's the problem?

Like most cable-damage failures (lots of threads about them if you poke around), the most common problems are:

--a damaged phase wire shorted to a damaged hall wire, or even to another phase wire, or to the axle (and thus the bike frame and anything electrically connected to it, possibly including battery or controller ground, etc); this destroys hall sensors and often damages the MCU in the controller itself so it can no longer read the sensor on that line, so if it has no sensorless mode it is no longer a usable controller. Phase-to-phase or phase-to-ground/etc shorts blow up FETs in the controller, and often show up with symptoms you are getting, and can be felt without power as hard-to-turn wheels. If the wheel is easier to turn forwards and backwards when the controller is not connected, then there are almost certainly blown FETs in it, which typically means replacing the controller (FETs often take out their gate drivers or even the MCU control lines when they fail catastrophically like this).

--The hall and phase wires are not now connected in the same order they were before (regardless of colors), which means the controller is not sending the phase signals in the right order / timing. If the controller has a self-learn function, you can use that to fix this. If not, you'll need to try different connections of phases between controller and motor until the motor runs correctly and smoothly at the lowest possible current. If it then runs backwards, swap hall wires around until it is correct, smooth, lowest current.
 
Hey!
Thanks for the help.
I switched the phase wires but unfortunately the motor won't run regardless of which combination i try. Just ordered a new motor kit. Maybe gonna try running the old motor with the new controller.
 
mhoch3 said:
.Just ordered a new motor kit. Maybe gonna try running the old motor with the new controller.

If the motor wiring is damaged, and if it damaged the controller, it will damage the new controller just like it did the old one (if it is the cause of the problem).

I highly recommend testing the wiring and examining it closely (because some failures are intermittent, when dealing with insulation damage especially at the axle exit).
 
Back
Top