KT Controller Intermittent cut out

General Discussion about electric bicycles.
Post Reply
GiantYukon   10 mW

10 mW
Posts: 30
Joined: Nov 13 2020 9:14am

KT Controller Intermittent cut out

Post by GiantYukon » Nov 13 2020 9:37am

Hey guys.
I bought a 45a KT controller for my 1500w Voilamart hub from csc on ebay. KT48ZWSRKTB-SJT02LB
Intermittently as I accelerate, with pedal assist or throttle, not always full throttle or level 5 pedal assist, happens with pedal assist 2 with weak assist strength of motor too, the power cuts out briefly and then comes back on. Not just from a standing start but also while I'm moving, and also when I just hold the back wheel up, with no load on the wheel.
My battery is 52v rated to 40A constant, with much higher bursts. Seems to be a reputable place, so I dont believe its the battery, especially since its intermittent, its hard to say how intermittent, but sometimes I throttle up 3 times and it happens, sometimes I throttle up 12 times and it happens. So I feel like that rules out battery since I can go full throttle 10 times and get no bad results.
I've tried different throttles, two different twists and two different thumb throttles, problem is still there, I've tried it with pedal assist not connected, still there, I've tried it with no throttle connected and pedal assist only and its still there.
I'm sure its the controller.
I started asking questions on facebook groups and I've found 3 other people with the same problem.
I messaged CSC and they suggested it was the soft start function, and asked for a video, its been over a week with no reply from them.
Anyone else with a similar problem? How did you fix it?

Thanks
David

User avatar
E-HP   1 MW

1 MW
Posts: 1837
Joined: Nov 01 2018 9:20pm

Re: KT Controller Intermittent cut out

Post by E-HP » Nov 13 2020 12:09pm

Try checking for loose phase wire connectors.

GiantYukon   10 mW

10 mW
Posts: 30
Joined: Nov 13 2020 9:14am

Re: KT Controller Intermittent cut out

Post by GiantYukon » Nov 13 2020 2:03pm

Thanks, def not loose, as part of the trouble shooting I tried different combinations of phase wires, all bolted in tight, isolated.
I can confirm is not loose phase wires.

GiantYukon   10 mW

10 mW
Posts: 30
Joined: Nov 13 2020 9:14am

Re: KT Controller Intermittent cut out

Post by GiantYukon » Nov 16 2020 12:35am

Any more ideas guys?

electric_nz   100 W

100 W
Posts: 105
Joined: Jan 07 2019 8:33pm

Re: KT Controller Intermittent cut out

Post by electric_nz » Nov 16 2020 2:14am

Does all power cut off? Like display blank and lights out? If so could be the battery BMS cutting power. If you can temporarily connect volt meter on the output of the battery you’ll see if it stays up or cuts out when the issue occurs

GiantYukon   10 mW

10 mW
Posts: 30
Joined: Nov 13 2020 9:14am

Re: KT Controller Intermittent cut out

Post by GiantYukon » Nov 16 2020 12:47pm

electric_nz wrote:
Nov 16 2020 2:14am
Does all power cut off? Like display blank and lights out? If so could be the battery BMS cutting power. If you can temporarily connect volt meter on the output of the battery you’ll see if it stays up or cuts out when the issue occurs
No, all other power stays on, its just the power to the motor it seems.

GiantYukon   10 mW

10 mW
Posts: 30
Joined: Nov 13 2020 9:14am

Re: KT Controller Intermittent cut out

Post by GiantYukon » Nov 21 2020 1:22am

I got it figured out!

Changing L3 to 0 fixes the hesitation.
Setting it to 0 changes it to Non Hall mode when the sensor in the motor has failed. Except that I dont think my sensor has failed. Its a new voilamart motor, and my cousin with csc 1500w motor has the same issue out of the box, as do some other people I found on the diy ebike page.
Either way...problem solved!

Post Reply