Victor Dupont
New member
Hi there!
As I am trying to troubleshoot a problem on my electric bike, and got stuck, I tried measuring the voltage on the phase wires, to know whether my controller is faulty.
I would like to know whether that looks normal or abnormal to you, since I have no idea what the correct values are, and I don’t know whether my methodology makes sense.
In order to have something that might make sense, I disconnected the phase wires from the motor, so that it doesn’t move. I kept the hall sensors and speedometer wires plugged, so that the controller has the information coming from the motor. I disconnected the brake cutoffs and lamp, to avoid them interfering. I also opened the controller, to be able to measure voltage directly on the circuit board, to rule out potential wire issues.
Basically it’s a pretty normal setup, except for the phase wires that are disconnected and the controller that is open.
I turn the pedal when I want to measure, and then I use a basic multimeter to measure voltage on each phase wire’s solder point.
Again, note that the motor doesn’t move. The pedal movement just ensures that the controller gets the signal to kick off the motor.
In order to change the sensors value, I simply turn the back wheel backwards and measure the hall sensors wire solder points to know where it landed.
Let me know if you think this method of measurement is not usable.
If it's of any use, my controller is a Lishui EPAC Drive System, part number LSW06-90B1CF SB.
When idle, meaning pedal is not turning:
When turning pedal:
- I made several experiments for each motor position, and noted the result of each measurement, separated by commas. I made sure to turn the wheel, and thus change the motor position, between each experiment.
- when I include an arrow, such as 0->9, it means that for a few seconds it was at 9, and after maybe 4 or 5 seconds it rose to 9
- twice I had results that were the same as when idle, and controller’s light was flashing differently, not regularly. After I turned the wheel it went back to « normal ». That’s what I indicated as « flashing ».
1. when idle, meaning the pedal is not turning, the yellow phase wire has 13 V voltage when measured using DC mode on multimeter. I would have expected 0V.
2. my measurements when pedal is turning seem to hint that in a normal setting, each phase wire would be at either 0 or 35V, which is close to the battery’s voltage, and that the wire with the 35V would be a color that is at 3.3V in the hall sensor cables. This is just my guess, tell me if that’s how it’s supposed to be
3. It seems to me that the most abnormal measurements seem to be on the yellow phase wire, when it’s supposed to be at 35V, and is instead at 6 or 8V
But again, I am just guessing, I have no idea what the correct values are.
Do you know whether these values are normal or not?
I previously tested for shorts between the phase wires, ground and battery positive, to detect a blown transistor, but everything seemed normal.
I also tested voltage on phase wires when they are connected to the motor. That way everything is exactly as in real life, except for brake cutoffs and lamp which are disconnected.
I only tested when it's idle, meaning I am not turning the pedal.
Here are the results:
As you can see, there is voltage even though everything's idle.
If my understanding is correct, phase wires are connected through the windings in the motor. Thus I interpret this as controller sending 13V on yellow phase wire, and because others are connected to it through windings in the motor, they are all at 13V.
Do you know whether these values are normal or not?
For those who are interested in the whole history of this bike’s problem, here it is: https://ebikesforum.com/threads/temporary-power-outages-and-motor-noise-megamo-park-urban.9226/
Thanks a lot in advance for the help!
As I am trying to troubleshoot a problem on my electric bike, and got stuck, I tried measuring the voltage on the phase wires, to know whether my controller is faulty.
I would like to know whether that looks normal or abnormal to you, since I have no idea what the correct values are, and I don’t know whether my methodology makes sense.
The way I measured is the following.
In order to have something that might make sense, I disconnected the phase wires from the motor, so that it doesn’t move. I kept the hall sensors and speedometer wires plugged, so that the controller has the information coming from the motor. I disconnected the brake cutoffs and lamp, to avoid them interfering. I also opened the controller, to be able to measure voltage directly on the circuit board, to rule out potential wire issues.
Basically it’s a pretty normal setup, except for the phase wires that are disconnected and the controller that is open.
I turn the pedal when I want to measure, and then I use a basic multimeter to measure voltage on each phase wire’s solder point.
Again, note that the motor doesn’t move. The pedal movement just ensures that the controller gets the signal to kick off the motor.
In order to change the sensors value, I simply turn the back wheel backwards and measure the hall sensors wire solder points to know where it landed.
Let me know if you think this method of measurement is not usable.
If it's of any use, my controller is a Lishui EPAC Drive System, part number LSW06-90B1CF SB.
Here are my results:
When idle, meaning pedal is not turning:
When turning pedal:
Some things to explain:
- I made several experiments for each motor position, and noted the result of each measurement, separated by commas. I made sure to turn the wheel, and thus change the motor position, between each experiment.
- when I include an arrow, such as 0->9, it means that for a few seconds it was at 9, and after maybe 4 or 5 seconds it rose to 9
- twice I had results that were the same as when idle, and controller’s light was flashing differently, not regularly. After I turned the wheel it went back to « normal ». That’s what I indicated as « flashing ».
There are a few things I notice:
1. when idle, meaning the pedal is not turning, the yellow phase wire has 13 V voltage when measured using DC mode on multimeter. I would have expected 0V.
2. my measurements when pedal is turning seem to hint that in a normal setting, each phase wire would be at either 0 or 35V, which is close to the battery’s voltage, and that the wire with the 35V would be a color that is at 3.3V in the hall sensor cables. This is just my guess, tell me if that’s how it’s supposed to be
3. It seems to me that the most abnormal measurements seem to be on the yellow phase wire, when it’s supposed to be at 35V, and is instead at 6 or 8V
But again, I am just guessing, I have no idea what the correct values are.
Do you know whether these values are normal or not?
I previously tested for shorts between the phase wires, ground and battery positive, to detect a blown transistor, but everything seemed normal.
Other measurement : with motor connected
I also tested voltage on phase wires when they are connected to the motor. That way everything is exactly as in real life, except for brake cutoffs and lamp which are disconnected.
I only tested when it's idle, meaning I am not turning the pedal.
Here are the results:
As you can see, there is voltage even though everything's idle.
If my understanding is correct, phase wires are connected through the windings in the motor. Thus I interpret this as controller sending 13V on yellow phase wire, and because others are connected to it through windings in the motor, they are all at 13V.
Do you know whether these values are normal or not?
For those who are interested in the whole history of this bike’s problem, here it is: https://ebikesforum.com/threads/temporary-power-outages-and-motor-noise-megamo-park-urban.9226/
Thanks a lot in advance for the help!
