Problem with controller/motor?

[Viraty]

Hello, I have a e-scooter that has a problem, i give it gas and it goes up to 5km/h stuttering then shuts off, this goes on for 5 minutes then it goes to 15km/h and shuts off completely. The Phase wires get super hot especially the Yellow one, I replaced and tested the Throttle and its reading accurate.

I Believe its the motor controller shutting off due to heat. When i checked the phase wires the yellow was not seated correctly and i crimped it again, still doing the same.

I am running 48V controller with a 2000W 48V Brushless motor.

This is the scooter https://www.sxt-scooters.de/en/Scooter-models/SXT-Monster.html

The phase wires gets super hot and the controller.

This problem has gone on for about 2 weeks now, any help would be nice. I have a multimeter and can test everything you all ask for.

 

[E-HP]

Hello, I have a e-scooter that has a problem, i give it gas and it goes up to 5km/h stuttering then shuts off, this goes on for 5 minutes then it goes to 15km/h and shuts off completely. The Phase wires get super hot especially the Yellow one, I replaced and tested the Throttle and its reading accurate.

I Believe its the motor controller shutting off due to heat. When i checked the phase wires the yellow was not seated correctly and i crimped it again, still doing the same.

I am running 48V controller with a 2000W 48V Brushless motor.

This is the scooter https://www.sxt-scooters.de/en/Scooter-models/SXT-Monster.html

The phase wires gets super hot and the controller.

This problem has gone on for about 2 weeks now, any help would be nice. I have a multimeter and can test everything you all ask for.

The symptoms are consistent with an incorrect phase/hall wiring order. Read and follow the troubleshooting guide below:

Testing BLDC motor's Phase Wiring - Hall Sensors and Wiring. - Electricbike.com Ebike Forum

Testing electrical components of a typical hub motor with a digital multi meter. First take a few minuets and look over the wiring going into the motor for cuts, scrapes, missing insulation and other wiring issues or poor connections that should be resolved first. Smell for evidence of...

electricbike.com

 

[Viraty]

Thank you for your response. Tried all the wiring/hall wiring combination and the problem is still appearing.

 

[amberwolf]

First, did the system ever work correctly?

If so, what specifically and exactly happened between the time it worked and the time it did not?



Phase wiring getting really hot is not normal, and is consistent with the controller driving the motor incorreclty--that is almost always because of wrong hall/phase timing, which is almost always because of wrong hall/phase order.

Does it have a sensorless mode? If so, disconnect the hall sensors and see what happens.


If it is not phase/hall timing, then it's usually an actual motor problem.

When it isn't that, it's that the wrong motor has been chosen for the application; being run at too low a speed and too high a load, and the motor itself will also be heating up far more than it should.

 

[Viraty]

It worked 2 weeks ago,

3 days ago i got a new throttle that came with a new harness and i installed it and it did not work . I later found out the Ground and power cables for the throttle where mixed. The system lit up but the motor stuttered and stopped.

When i unplugged the hall wires the motor did nothing.

I think something shorted inside the controller.

I'm gonna order a new controller and get back to you with the results.

thank you for the great feedback and troubleshooting steps!

 

[amberwolf]

Did the throttle only have the three throttle signal / 5v / ground wires, or did it also have a battery meter or controller switch, etc in it?

If the former, then it's much less likely to have damaged anything in the controller, just the throttle itself, from a miswire of any combination. If the throttle itself was damaged, it wouldn't cause the issues you see, it would either just not provide a signal to the controller to tell the motor to spin, or would give the wrong output and it wouldn't spin as you expect it to. But there wouldn't be any heating.

If the latter, a miswire of battery voltage to the 5v line on the controller could have damaged not only the MCU, but every 5v device on the system, including the motor hall sensors, any PAS sensor, ebrake sensors, etc. Anything connected to the wire that carried battery voltage.

Battery voltage to ground would've just either turned the system off (BMS protection, etc) or burned / melted the ground and/or battery wires to the throttle.

Battery voltage to throttle signal line of controller would've just damaged the MCU...but sometimes this level of damage can propagate thru the MCU to things the MCU is connected to--this can include the data lines to a display, for intance, and damage the display (usually causing a comm error).



If by "harness" you also mean other wiring in the system besides *just* the throttle wiring, then any device in the system anywhere that any of it connected to could be damaged; you'd have to trace out which wires went where to see what could have been.

 

[Viraty]

Did the throttle only have the three throttle signal / 5v / ground wires, or did it also have a battery meter or controller switch, etc in it?

If the former, then it's much less likely to have damaged anything in the controller, just the throttle itself, from a miswire of any combination. If the throttle itself was damaged, it wouldn't cause the issues you see, it would either just not provide a signal to the controller to tell the motor to spin, or would give the wrong output and it wouldn't spin as you expect it to. But there wouldn't be any heating.

If the latter, a miswire of battery voltage to the 5v line on the controller could have damaged not only the MCU, but every 5v device on the system, including the motor hall sensors, any PAS sensor, ebrake sensors, etc. Anything connected to the wire that carried battery voltage.

Battery voltage to ground would've just either turned the system off (BMS protection, etc) or burned / melted the ground and/or battery wires to the throttle.

Battery voltage to throttle signal line of controller would've just damaged the MCU...but sometimes this level of damage can propagate thru the MCU to things the MCU is connected to--this can include the data lines to a display, for intance, and damage the display (usually causing a comm error).



If by "harness" you also mean other wiring in the system besides *just* the throttle wiring, then any device in the system anywhere that any of it connected to could be damaged; you'd have to trace out which wires went where to see what could have been.

For the throttle there was 3 diffrent plugs. One with three wires for the throttle. One plug with 2 wires for indicator light (battery lights) and one plug with 2 wires for boost/eco.

I really hope its just the controller. I did test the conuctivity (no spell check on phone) of the phase wires. How can i test the hall wires?

 

[amberwolf]

Are you trying to test the wires, or the hall sensors themselves (and the signals they produce)? Different tests with different expected results.

Testing the wires is harder because you have to open the motor and controller up to do a true test, and given the data so far should not be necessary, but testing the hall signals is usually pretty easy.

The signal test is done with leaving the motor and controller connected, and the controller powered on but inactive. Many systems have open-frame connectors that let you touch the contacts from the back with the meter leads. If yours are waterproof types, you'll have to do this test inside the controller or by opening up the cable somewhere along it's length, preferably on the controller side of the connector (both because it shows what is reachign the controller and because if your'e replacing the controller it won't matter if the cable /etc here is damaged).

Set the multimeter to 20 DC Volts and put the black lead to battery negative or hall ground, whichever is easier (they are the same electrical point if the system is working and on). Put the red lead to the hall 5v and note the reading as you slowly rotate the motor wheel both backwards and forwards by hand. Move the red lead to each hall wire in turn and note the reading, and which wire the readingg is ffor.

For the ground wire y ou should get 0v. THe 5v wire should read between 4.5-5v, it's very common for it to be ~4.5v.

For the three signal wires you should get around 0.8v for the lowest, and 5v for the highest, alternating as the wheel is rotated.



What specific phase wire test was done? (note that given the symptoms and stated cause, there should be no problems with the phase wires or FETs or motor windings, etc, unless the overheating was severe enough to damage insulation).

My best guess based on the info so far is that the hall signals are not correct at the controller, either because the controller is damaged at the MCU or LVPS and can't read them, or because the signals are not being generated correctly at the halls themselves (because of heat damage or because of voltage damage from the wiring issue).

 

[amberwolf]

With the swapped wires, were they *only* the 5v and ground wires in the throttle? Or were any other wires in the other parts of the harness swapped or misconnected at any time?

If it was *only* the 5v and ground being swapped, then the symptoms you see make no sense for the problems that could cause.

The only things that causes are:
-- damage to the throttle hall sensor, which just means it gives no output, or wrong output, so you don't get the expected amount of motor drive for a given throttle position.
--damage to the controller LVPS 5v, usually killing it completely so the controller won't operate at all, sometimes causing incorrect voltage output that's too low for the controller to operate.
--very occasionally it could damage the MCU itself, preventing the controller from operatingg at all.
--very occasiontally it blows the 5v regulator in a way that also damages teh 12v / 15v regulator, but that's irrelevant in this case because no 5v means no controller operation anyway.

So, if there wasn't some other change to the system, or some other miswire or short (like battery voltage to 5v or some signal line into the controller), the symptoms you have don't match, and troubleshooting can't be done based on that info, and probably is going to require changing some parts to find out what's going on, after you test to make sure your signals from sensors, etc are all ok, and all of your connections, especially those carrying high current, are good. .