wheel noise with new controller

Ozwallt

Finding my (electric) wheels
Aug 16, 2024
5
0
Hi
I used to have a swytch kit on my bike but I blew the controller somehow (different story for a different thread). Anyway decided to go my own way and replaced the controller, display and PAS (all KT) with generic gear.
Everything works but the wheel motor is much noisier that it was with the swytch controller. It makes me think either I've got wrong controller or I need to adjust a setting.
Any pointers/ideas I could try would be appreciated.

Original controller was 36v,6A (max 12A).
New is 36v, 7A (max 15A)
I've got a KT-LCD5 display (had to change c1 to accept 12 magnet PAS)
Link to manual:

Thanks!
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,713
3,119
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Is it a sine wave or square wave controller? Sinewave has SVPR in the designation after the voltage, square wave has something different with a Z (?) In it.
 
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Ozwallt

Finding my (electric) wheels
Aug 16, 2024
5
0
The new one is KT 36/48ZWSR - so I'm guessing square.
The old controller is a Swytch licensed doodah (LSW1542-1-10-1E).
If it is a sine wave controller am I damaging anything by using the square wave?
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,713
3,119
Telford
The new one is KT 36/48ZWSR - so I'm guessing square.
The old controller is a Swytch licensed doodah (LSW1542-1-10-1E).
If it is a sine wave controller am I damaging anything by using the square wave?
Square wave controllers make the motor noisier and rougher than a sine wave one, especially if you give high power at low speed. The noise comes from the individual commutation pulses. It's a bit like the motor being knocked round rather than pushed round. It sounds a bit like gear noise, and it disappears as the rpm goes up. It's much more noticeable with sensorless motors.

In summary, just the 25% increase in current would cause a 25% increase in noise at low rpm. Without hearing the noise, it's be difficult to give a definitive answer. Some square wave KT controllers are sensorless, so can we be clear - do you have the hall sensors connected or not?
 
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Ozwallt

Finding my (electric) wheels
Aug 16, 2024
5
0
This is it.
Like you said it does sound a little better at higher speed.
I think I have the hall sensors connected (not sure how to confirm sorry!)
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
If it has a hall sensor connector then it will be a KT square wave sensored controller.

Not all KT square wave controllers are sensorless.

You can try to cross check it here.


Ebike solutions have a good selection of KT controllers of various kinds.
 
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Ozwallt

Finding my (electric) wheels
Aug 16, 2024
5
0
Thanks everyone.
I'll get a sine wave controller on the next paycheck I think.
In the mean time :Is the square wave damaging the motor?
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,713
3,119
Telford
Thanks everyone.
I'll get a sine wave controller on the next paycheck I think.
In the mean time :Is the square wave damaging the motor?
No. Nothing to worry about id the noise is what I described. There are other causes of noise, mainly something rubbing on it, especially when the washers on the axle aren't right.
 
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Ozwallt

Finding my (electric) wheels
Aug 16, 2024
5
0
No. Nothing to worry about id the noise is what I described. There are other causes of noise, mainly something rubbing on it, especially when the washers on the axle aren't right.
Thanks. It's definitely an electrically induced noise.
 

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