PAS not working

Greg687

100 µW
Joined
May 26, 2021
Messages
8
Hi all. My project is still not running right. Apparently the wiring diagram I got had the throttle and PAS wires mismarked, and I had the PAS connected to the throttle. (explains the choppy application of power). Anyway, I went to add a throttle and found the error. I now have throttle, but no PAS.
It's a 250w geared rear hub motor, 36V battery, KT 36v dual mode controller, and LED880 control panel. Brake sensors, throttle, walk assist, and led's all work. I have 5v at the PAS wiring, and I have 3 different, all tested good, PAS sensors. None work with this controller, or the controller PAS circuit does not work.

ANy thoughts on next steps? I'm quite happy that I was able to add a throttle due to the upgraded controller, but I would love to see the PAS work, too.

Thanks for any help.
 
From your post I gather you have engineering ability , so prob bit of a long shot , but is you magnetic disk set up correctly I have mine almost touching the sensor ,good luck
 
If your PAS sensor isn't configured to match the controller settings, it may not work. Does the motor turn or do anything when you pedal backwards?

The KT LCD3 and LCD4 displays I've used have a parameter called C1 that governs the interpretation of PAS sensor signals.

Screenshot_20210709-130651.png
 
The LCD880 is a basic display with no configuration possible that I can find. I've tried the PAS forwards and backwards, with all 3 PAS sensors. The vendor said the controller is set up for an 8 magnet PAS, which I have 2 of. The Motor turn forwards great under throttle and pedal assist, just nothing with PAS.
 
Greg687 said:
The Motor turn forwards great under throttle and pedal assist, just nothing with PAS.
Pas is peddle assist you seem to contradict yourself here, am I right in thinking before you connected pas sensor out to throttle in on controller , you not touched pas in on controller? :pancake:
 
You need to verify you have power/ground on the right two leads, and that leaves signal on the remaining one. Then with your volt meter, verify that signal flips between 0 and 5 volt as the disk turns. Only then have you tested the sensor.

If this is a separate disk and sensor combo (two pieces), you may be have the magnets too far away, or flipped in the wrong direction. The sensor reacts to whether the flux field is north-south or south-north. and this allows the controller to ignore you you pedal backwards.
 
Throttle works plugged in to controller PAS port. ( wiring diagram may be wrong ) And PAS does not work plugged into controller Throttle port. Does PAS work plugged into the port that the throttle is now plugged into, with no throttle connected to controller ? You may already know that the 8 magnet disk has an active side , usually identified with the letter "A" , that must face the sensor. Usually designed for left side of bottom bracket. So if mounted on right side, the sensor has to be rotated 1/2 turn in the mount to sense forward rotation of the magnet disc.
 
Throttle is plugged into the throttle port and works as the throttle should. PAS plugged into PAS and does nothing. I've tried all the ways to install it, and I have 2 new ones, though the first one tests out fine on the "EBike tester" I bought. The other 2 new ones test the same.

I have 5v, how do I find out which of the others is ground and data? I've tried the PAS connected in every possible way.
Thanks
 
Well, another update. I wrote down all the possible wiring combinations of the PAS, and did them again. I must have missed one before because it is working now. However, the display setting of low, medium. or high makes no difference on motor output. It goes full on no matter the setting or pedal speed.
 
by E-HP » Jul 12 2021 9:19am
"still waiting for the links"

Links?
EDIT: found where you asked. I posted a video, but I guess the PAS sensor links don't matter. It's working now, though now I think I have a display to controller issue. I think I need an LCD3 or better unit to adjust the amount of output.
 
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