Motor or Controller broken?

Today I was pushing my 2000W bike too hard at the hot weather.

It has a 40A KT controller with the LCD3 display and I think the motor is this one:
https://bmsbattery.com/ebike-kit/471-q11-48v1kw-rear-driving-disc-brake-hub-motor-ebike-kit.html

Power was suddenly gone and the motor became very hard to turn. Both the controller and the motor were very hot.
I stopped and gave it a few minutes to cool down a bit, but no success. At least it happened only a minute from home.

The motor is not turning at all. Sometimes for only a second but very rough running.
There is now a lot more resistance when turning the wheel by hand.
I replaced the connectors of the three phase wires, but this did not change a thing.

When using the throttle, in 98% of the time the motor will not spin at all and the LCD3 shows INFO_06.

It shows the INFO_06 message also when none of the phase wires are connected, when all of them are connected and when some of the are connected.

Is something inside the motor broken or a blown FET?

If the motor is hard to turn by hand then chances are its the motor.

06 is a short in the motor phases

Disconnect the motor phase wires.

Test the resistance between all the phase wares at the connector (ie resistance from green to blue, green to yellow, yellow to blue). If they are all the saem the motor should be ok, maybe.

While the motor is disconnected, turn the controller on. if the 06 error persists then it may be a blown FET.

The phase wires are touching if there is resistance when no power is applied.
You may have melted something, like a connector or maybe u fried the controller.

Step 1 - Unplug the motor sensor wires and the motor phase wires and see if there is still resistance.
Look at your wires from motor all the way to the end of your unplugged wires.
Look at the wires coming out of axle, inspect it closely.
Look at your connectors closely as well.
If there is still resistance when everything is unplugged, then go back to step one.
Final step is then the phase wires are touching, so you gotta open up motor, and inspect it some more.

Shorted, probably.

Is it easy to turn when disconnected off the controller?

Test continuity, on motor phases (between each other), then between phases and axle.

You may have only a small failure, hall sensor possibly. You never know, until it is tested.

Resitance phase wire via controller:
Green to yellow phase wire: 10kohm
Blue to yellow phase wire: 10kohm
Blue to green phase wire: 20kohm
Is that normal?

Resistance phase wire via motor:
All combinations <1Ohm

Motor is hard to turn also with everything disconnected and power off.

According to the manual, 06_info is a connection failure at the controller or the motor

Probably it is the motor because it became hard to turn.
What exactly happened to you think? If it is shorted, it would only be hard to turn if connected, correct?

Motor is not spinning at all. I can only get it spinning sometimes for a few split-seconds if I turn the wheel by hand and open the throttle.

By the way, is there a better quality motor with the same weight available that can take 2000W?

I mentioned earlier that the motor is also hard to turn when disconnected. This is not the case. Probably there were two phase cables touching.
It turned out that it was the yellow phase wire which is shorted to 0V via the controller.
Looks like a blown FET.

Blown fets are not making a motor hard to turn when disconnected. You have a short in the motor, that caused the controller failure. You had no dropout spinout? Because that is the most common reason to short phase wires. Test continuity between phase wires and axle, there should be none.

Re: hard to turn motor, how likely is it that a magnet has become unbonded and is now fouling the stator? Are we talking realy hard to turn, kinda grinding?

As has been stated already, you probably shorted out a phase (phase wire). Something got hot and melted.
A loose magnet would cause a grinding sound that wasn't there before.

As instructed, fully examine your motor cable from the connector to where it goes into the motor.
A shorted phase might show up as a continuity from your phase wire to your axle.

If there is no indication of a short on the outside cable, then you may have to open the motor.

Other tests before opening the motor are, testing with a known good controller to see if the motor works, or, if you have time buy an e-bike brushless motor controller tester for around $20-$25 dollars USA
and test for faults in the whole system.

Opening the motor and carefully inspecting for a short is also an option. I would at least test with another controller before going through that.

hias9 said:

I mentioned earlier that the motor is also hard to turn when disconnected. This is not the case. Probably there were two phase cables touching.
It turned out that it was the yellow phase wire which is shorted to 0V via the controller.
Looks like a blown FET.

Click to expand...

In this recent posting the OP indicates that the motor is not hard to turn then disconnected and wires kept separated, and that the controller is likely shorted.

Sorry for the confusion.
When I first tested to turn the motor diconnected, it was hard to turn. I guess I made a mistake during that and 2 phase cables were touching.
When I tried it later, it was not hard to turn any more.

After some measurements it came out that the resistance from one phase cable via the controller to 0V (GND) was zero. Also I think the resistances between the phase wires via the controller should be 20kOhm. However it was 20kOhm for one pair and 10kOhm for the other two phase wire pairs.

So the problem seems to be the controller which I am going to replace.