• Howdy! we're looking for donations to finish custom knowledgebase software for this forum. Please see our Funding drive thread

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

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.
 

Attachments

  • oldcontroller.png
    oldcontroller.png
    985.8 KB · Views: 5
  • newcontroller.png
    newcontroller.png
    488 KB · Views: 5
Not sure if this will be the answer, normally when I put an ebike together with a KT controller I use say a KT-LCD 3 display so I can program in the motor parameters, which include basic settings, P parameters and C parameters. If I was using a basic display I would have plugged a KT-LCD 3 display in first and set the controller up then switch back to the basic display. I cannot find any info on the original controller which is not a lot of use. I assume it is a hub motor you are using, what make, model etc is it or what bike? On the controller wiring diagram what have you connected / not connected, tick with a pencil and attach a picture. Have a look on YouTube at the KT-LCD 3 display.
 
Not sure if this will be the answer, normally when I put an ebike together with a KT controller I use say a KT-LCD 3 display so I can program in the motor parameters, which include basic settings, P parameters and C parameters. If I was using a basic display I would have plugged a KT-LCD 3 display in first and set the controller up then switch back to the basic display. I cannot find any info on the original controller which is not a lot of use. I assume it is a hub motor you are using, what make, model etc is it or what bike? On the controller wiring diagram what have you connected / not connected, tick with a pencil and attach a picture. Have a look on YouTube at the KT-LCD 3 display.
China clone bike, no information about the rear motor hub except 36V 500W. But as the previous post showed for a different user having the identical problem, the KT controller is having phase / hal mismatch with the motor.

Everything except the PAS/cruise control/speed limit/EABS wires is connected. Only tried the bike with throttle. After doing another HAL / Phase wire combination it works "barely ". At least noise is gone, it does accelerate but very little torque and only 1 speed setting.

Seems the old controller was more of a proprietary as it does work from the getgo. I remember it had a basic 3-speed LCD throttle handgrip display. For me a basic display would've been all that's necessary. But looks like even with configuring the parameters the torque will never be quite as high as it should be since the other user already played around with it.

I've ordered another no brand china controller + S886 lcd display as it's sold closeby and I can get it before end of next week. But I'm also thinking of maybe ordering a LCD3/LCD7 for the KT and have a go with the parameters. Sad thing is the sensorless 500W KT controller is 12.8cm.. Which is like 2cm too much to fit my bike otherwise that would've probably been my best alternative.
 
Last edited:
Normally the HAL / Phase wiring is to a basic standard, that's why I always use the KT series, but one needs in the first instant one needs to get the HAL / Phase wires correct. So have a look at this:- Electric bike wiring - Bike Forums
That's the wiring guide i followed. Swapping Yellow - Blue HAL | Yellow - Green Phase made the motor growl and throttle issue go away but it's still not 100% functional. The KT controller isn't delivering much power to the motor hub same problem as the other guy.
 
My only thought at the moment is controller setup, I had it where the motor parameters are wrong and it's run like crap, in that case it was the motor characteristic parameter, P1 = Motor Gear Reduction Ratio × Number of Rotor Magnets, where I had to guess the figure and slowly adjust it to get the motor running correctly, there are other parameters as well. I had this problem with a 500 watt non geared rear hub motor which had only a power switch and PAS on it, put a KT controller and display on it and had to start from the beginning going thro' the parameters to get it running correctly. I still cannot be totally sure it will solve the problem but have used at least six KT controller and display combinations before changing to Tongsheng TSDZ2 mid drives.
 
My only thought at the moment is controller setup, I had it where the motor parameters are wrong and it's run like crap, in that case it was the motor characteristic parameter, P1 = Motor Gear Reduction Ratio × Number of Rotor Magnets, where I had to guess the figure and slowly adjust it to get the motor running correctly, there are other parameters as well. I had this problem with a 500 watt non geared rear hub motor which had only a power switch and PAS on it, put a KT controller and display on it and had to start from the beginning going thro' the parameters to get it running correctly. I still cannot be totally sure it will solve the problem but have used at least six KT controller and display combinations before changing to Tongsheng TSDZ2 mid drives.
Yeah but yours was probably still able to run correctly despite not being finetuned? :) In my case even with re-configuring some of the HAL / Phase wires, switching between levels (low | med | high) does nothing, speed and power draw is constant. And it's drawing so little that uphill it comes to a stop. Only able to reach 20mph on flat roads.

Suspecting it's some kind of false-positive scenario. I just don't understand why the controller <--> display logic isn't working when I only changed phase / HAL wires..

In my head, that part should only concern smooth rotation. Even if the power draw is little, the modes ( low, med, high) should still be regulating the controller output. And I'm not seeing anyone else with similar problem having solved that part after their reconfiguration.
 
KT's phase/sensor wiring follows the Bafang standard. I've hooked up four different Bafangs and they spun up, Also motors from Ecotric and Huffy ebikes, the ebikeling products, AKM and MXUS. I figure everyone else that makes motors in a sweat shop will copy that scheme faithfully,

I'd go back to a defective controller hypothesis. Maybe it's overheating and that's why throttle shuts down.
 
KT's phase/sensor wiring follows the Bafang standard. I've hooked up four different Bafangs and they spun up, Also motors from Ecotric and Huffy ebikes, the ebikeling products, AKM and MXUS. I figure everyone else that makes motors in a sweat shop will copy that scheme faithfully,

I'd go back to a defective controller hypothesis. Maybe it's overheating and that's why throttle shuts down.
It should be the same standard. That's what I expected aswell because the core is a 9Pin Waterproof Wheel Motor Extension Cable coming from the motor hub I ordered from Aliexpress.
Changing to a KT brand would be as simple as ever. But that would mean this guy had had the exact faulty controller as mine. Although he seemed to have improved just by a little playing with parameter settings.

I've ordered another controller that I got for a good price which will be arriving this week. Attached picture.
If the problem goes away after changing over to that, then I can probably confirm the KT controller is at fault in one way or another. I would've gotten the sensorless KT controller to try out, but I can only fit the 15A/350W. Which seems a bit too small for my 500W motor on 36V.
 

Attachments

  • controller3.jpg
    controller3.jpg
    314.2 KB · Views: 6
Last edited:
alan0048, I think we are at the big hammer / big vice stage, which means either you bash it or squash the faulty controller or a bit of both, doe's not do a lot for the controller but makes you feel better. Please keep in touch to let us know the outcome or to chew any more questions you may have.
 
alan0048, I think we are at the big hammer / big vice stage, which means either you bash it or squash the faulty controller or a bit of both, doe's not do a lot for the controller but makes you feel better. Please keep in touch to let us know the outcome or to chew any more questions you may have.
Im gonna go through the extension cable one more time and check for continuity for the hall wires. I do remember the new one I bought from Aliexpress is A LOT more tight than the previous. So If I'm lucky perhaps the HAL wires aren't making enough connection because those pins are shorter than the 3 larger phase wires otherwise I'll update once the new controller arrives.
 
Last edited:
Final update:

I swapped controller to my new 20A Intelligent brushless motor controller and problem went away. So there was never any problems with the motor or HAL sensors. Kept PAS, Throttle and Brakes that I had ordered for my previous KT controller. Just had to rewire some of them but no problem.

I don't know what was wrong with my previous KT controller but seems it must've been faulty from factory. I still have a sensorless KT controller on it's way from China (pswpower) that i had ordered as a backup, but I will probably keep that for another project or sell along with my LED display as a package deal.

Thanks for the help and input by everyone! Still was of great help.
 
Sorry if this is irrelevant (or too late) as I didn't wade through all the details. You talk about getting a sensorless replacement and I can't tell if the old controller was sensorless but your new controller is definitely a sensored controller.
 
Sorry if this is irrelevant (or too late) as I didn't wade through all the details. You talk about getting a sensorless replacement and I can't tell if the old controller was sensorless but your new controller is definitely a sensored controller.

Old controller was kt36/48svprd-hrd01 (sensored). Current controller is also sensored.

The sensorless KT controller (kt36/48zwsrmh-20a) was ordered as a backup in case there was something wrong with the HAL sensors on the motor side of things. That did not end up happening and all is working now.

Edit: The one I bought was not powerful enough on 36V, top speed 17mph. It's better suited for 48V at 500W now it's more akin to 350W. But at least i narrowed down the problem to the previous controller so I will know what to look for next time unless the sensorless controller manages to fit inside :)
 
Last edited:
Back
Top