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KT controller, noisy motor, throttle turning off periodically. Compability issue or?

alan0048

100 mW
Joined
Apr 3, 2024
Messages
46
Location
Sweden
After swapping controller/display/throttle for another brand, KT the ebike isn't working properly.
I am not sure wether the new controller, kt36/48svprd-hrd01, is malfunctioning or if it's not compatible with the motor hub which is unknown.

Everything is connected as it should be but the motor is much more noisy now when riding, especially during startup. The speed isn't what it should be and the throttle only lasts for about 5 seconds before turning off. The system stays on but to get the ebike to ride again I have to let go of the throttle and press it again.

I'm asking if anyone had encountered a similar issue, or if you know based on the difference of the controllers what the problem might be? I have tested the controller with both a KT-LED890 and 880 display but the controller / motor behaves the same. PA, light + horn switch, throttle? and display seems to otherwise work as intended which is why I'm having hard time to think the controller is bricked.

The previous controller was a Brushless DC motor controller 120* angle. The KT controller is a Brushless motor controller Sinewave.
Any ideas? I'm totally lost of why the new controller isn't working!
 

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motor growling controller non compatible example
This youtube video shows almost what it feels like for my wheel/controller. The same loud noise during startup. His solution was replacing a ZWS(square wave) controller for a SVP (sine wave). But can that be the case for me? Both original and new controller are DC brushless, one is explicitly sine wave but the other only says 120* angle. So that means it sine also?

Or could it be, the old controller is a square wave? DC motor control 120-degree trapezoidal drive?
 
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Yes. I've had the same problem with KT sinewave controllers. They shouldn't growl. I think the motor isn't being driven with symmetric phases so it makes noise. .

One was also a brand new controller. I knew something was wrong because I had built two conversions using the same motor and parts so I could feel the difference in power. I got the unit replaced.

It happened again with another controller. Started growling during a ride. It died before I got home. My fault. I had the controller in a plastic controller box, but I mounted the box upside down and it took on water. It eventually seeped inside. Saw the corrosion on the circuit board.
 
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Yes. I've had the same problem with KT sinewave controllers. They shouldn't growl. I think the motor isn't being driven with symmetric phases so it makes noise. .

One was also a brand new controller. I knew something was wrong because I had built two conversions using the same motor and parts so I could feel the difference in power. I got the unit replaced.

It happened again with another controller. Started growling during a ride. It died before I got home. My fault. I had the controller in a plastic controller box, but I mounted the box upside down and it took on water. It eventually seeped inside. Saw the corrosion on the circuit board.
Have you had any luck with square wave KT controllers? I'm beginning to think maybe the old controller wasn't a sine wave as I thought. I've sent a mail to the company so I'm waiting for confirmation. Forgot there was such a thing as 120° square-wave commutation for brushless DC motors. I just assumed sine wave when the word "phase angle" came into play.

Yeah, when I pedal normally the rear wheel / motor doesn't sound at all. it's only when you feed it power, like you said first impression had to do with non symmetric phases.

If not, do you know if It's possible to use a Square Wave controller instead? Are they interchangeable with a sine wave? Or does the motor hub only allow for one type?
 
I used square wave controllers for my first hub motor conversions, and everyone said sine wave was quieter, Would you believe my first sine wave controller application was the one that growled? I had the identical motor with a KT square wave humming away.

To be honest, if that had been my first conversion, I would have thought it normal and probably would have accepted the lackluster performance, but since that noise is a symptom of circuitry malfunction, the controller or motor would have likely burned out, The other controller that growled didn't run more than a few miles and I pushed the bike home.

Square or sine wave shouldn't matter.
 
I used square wave controllers for my first hub motor conversions, and everyone said sine wave was quieter, Would you believe my first sine wave controller application was the one that growled? I had the identical motor with a KT square wave humming away.

To be honest, if that had been my first conversion, I would have thought it normal and probably would have accepted the lackluster performance, but since that noise is a symptom of circuitry malfunction, the controller or motor would have likely burned out, The other controller that growled didn't run more than a few miles and I pushed the bike home.

Square or sine wave shouldn't matter.
I'm tilting towards maybe choosing a sensorless controller if it happens to be something wrong with the HAL sensors. Minimizing all risk factors I'm building this bike for another but I'm scared or ordering a similar sine wave controller after this haha..

Saw that KT sensorless controllers are all square wave. Issue is the 20A are 12.8cm which is slightly larger than the sensored sine wave 9-ish cm..

Any suggestions for square wave or sensorless controllers you had to deal with that works?
 
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I've owned a sensorless KT controller although it was only 17A, The bike was reliable, but is in storage. I have found KT controllers to have the best pedal response, although that's subjective. Wouldn't consider anything else for future projects.
 
I've owned a sensorless KT controller although it was only 17A, The bike was reliable, but is in storage. I have found KT controllers to have the best pedal response, although that's subjective. Wouldn't consider anything else for future projects.
Do you have a link or know the model name for the 17A? For a 500W a 17A sensorless would also work
 
You likely need to swap phase and hall wires to get to the smooth running combination. It's a pain, but sometimes you get lucky and it's only swapping two conductors.

 
You likely need to swap phase and hall wires to get to the smooth running combination. It's a pain, but sometimes you get lucky and it's only swapping two conductors.

I tried swapping phase wires in different combinations, Yellow/Green/Blue. Found the same chart through a Reddit post. But only the correct color coding worked "best".

I haven't tried using different HAL sensor wires, I might do that now just to try even tho I don't believe it will make much difference.

Main problem still is. Motor is noisy, it becomes much more noisy when I ride it and throttle rather than holding up the wheel in the air. And the throttle goes to zero after 4-5 seconds after reaching max rpm. Hopefully Hal sensor fixes it.. I will try now
 
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I had to swap the halls on my first kit installation. I decided to go with a KT sine wave rather than the cheap square wave that came in the kit. I had to swap the halls to get that one to work. Just keep the red and black conductors aligned, and avoid shorting anything.
 
I had to swap the halls on my first kit installation. I decided to go with a KT sine wave rather than the cheap square wave that came in the kit. I had to swap the halls to get that one to work. Just keep the red and black conductors aligned, and avoid shorting anything.
Do you remember which order you swapped the yellow/green/blue HAL sensor wires? Just rh HAl not the phase wires in combination aswell?
 
I'll take a look later. I have the motor and controller sitting in my store room, so I just need to get to them lol.
That would be much appreciated, sitting in the garage now trying get this a last chance before having to order a sensorless controller 😅
 
I had to swap the halls on my first kit installation. I decided to go with a KT sine wave rather than the cheap square wave that came in the kit. I had to swap the halls to get that one to work. Just keep the red and black conductors aligned, and avoid shorting anything.
Holy mother.. I think it's working

Don't wanna jinx it but sounds a lot better. Did the very last step. yellow/blue HAl + Green/Yellow Phase
Throttle isn't shutting down. I'm gonna put the bike together and take it for a spin
 
That would be much appreciated, sitting in the garage now trying get this a last chance before having to order a sensorless controller 😅
Holy mother.. I think it's working

Don't wanna jinx it but sounds a lot better. Did the very last step. yellow/blue HAl + Green/Yellow Phase
Throttle isn't shutting down. I'm gonna put the bike together and take it for a spin
Great! Report back after your test ride!
 
Great! Report back after your test ride!
Working to 70%.

Noise is gone, throttle working. But another problem arises. The led display is stuck on 1 speed mode regardless if I change low / medium / high.

I've tried both 890 / 880 led displays same thing. So while the changing HAL and Phase wire worked the last new problem is getting speed modes working. No idea where to go from here tho.

Speed is also very weak, doesn't have enough power to get uphill.
 
Disabling to the controller with the special cable that came with the KT controller, using only throttle feels like the controller is still only delivering a certain amount of power to the motor.

My previous 17A controller could deliver more power than this.
 
I think your problem is that you are using a KT LED display.

These displays are very basic and only the P paramters can be set up on them. You can’t set any of the C parameters.

To configure them properly a KT LCD display is needed with all of the correct parameters set up and then it needs to be connected to the LED display so the parameters can be copied over.
 
I think your problem is that you are using a KT LED display.

These displays are very basic and only the P paramters can be set up on them.

To configure them properly a KT LCD display is needed with all of the correct parameters set up and then it needs to be connected to the LED display so the parameters can be copied over.
Yeah I get they aren't very advanced. But feel slike when I just use throttle the controller ought to give the very maximum because I'm shorting out the display. So there is nothing to limit anymore.

Very strange don't have a spare display around. But feels strange the speed stays the same with or without using the led display.

The fact it's not even registering any different speed steps. All from changing HAL and Phase wires?Dayum thought for a second everything was gonna work..
 
I think when you are bypassing the display the controller is stuck in PAS 1 which is limiting the power even when you are using the throttle.
 
I think when you are bypassing the display the controller is stuck in PAS 1 which is limiting the power even when you are using the throttle.
Well that could be a possibility. I guess I have no other choice than trying a LCD display. I ordered the cheap one just because I wanna keep things simple
Don't need anything else than low / mid / high mode. No current / power limit etc. Just hook it up and work.

Everything else seems to work after the hal/phase change. Just hate the uncertainty if the new lcd display can't communicate properly and it's still stuck on some low speed/power mode.

Any suggestions for what display?
 
KTLCD 03 display will work well or if you are feeling flush with money the KTLCD 08 is very nice.

You can use either of those displays to configure your LED displays if you want to keep your cockpit simple. But you will need to make or buy a special link cable.

A couple of the cheaper KTLCD displays will give you the same problem as your LED displays so stay away from them.
 
His Dongwan controller was 17amps and his new KT controller is 10amps and it’s probably stuck in PAS 1 so the motor won’t perform too well until he can get the display configured properly.

The advantage of using a good display is that he can see how much power is being drawn off load. If it’s more than 100 watts with the wheel in the air then he can tell straight away if he has his phase/hall combinations mismatched.
 
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