Carrera Subway E - KT Conversion Issues

[dylan]

Hello
I would be most grateful for any advice on a strange issue I have.
I have converted a Carrera Subway E as follows:
Removed battery & standard cabling
Kept original HESC 250W motor
Using all new kit, 48V 12.5Ah Hailong case battery with KT36/48ZWSRM (9-FET 22A) controller with KT LCD5 display, PAS & Throttle
The bike runs fine apart from one issue, the motor cuts out with full throttle ONLY FROM STANDSTILL (fine once moving)
The bike will start to pull for a fraction of a second then cut out (this can be repeated without turning the bike off & on)
If I hold the throttle open for a few seconds once the bike has cut out (so bike is standing still) I sometimes, not always, get a 06 error
the display always remains active
If you pull away slowly for a couple of seconds you can then use full throttle with no problems
when I pull away with PAS only the bike is already moving so it doesn't appear to cut out
Once moving the bike pulls hard, no hesitation & is very responsive
If I set current limit C5=3 (50% current) the bike doesn't cut out but I would prefer full power
The batteries I am using have a 30A BMS & work well on other bikes pulling 22A to 30A
This is what i have already done:
Tried different 48v batteries (fully charged), KT36ZWSRTB (6-FET 15A) controller (& another 6-FET KT controller), LCD6 display & throttle
Checked the motor halls resistance between phases (all same resistance reading)
Checked the motor cable waterproof connector is firmly pushed together
Made sure battery (Inc fuse connector) & phase connections are good & tight
Reset all P & C settings via C10=Y
Here's my P & C settings:
P1=87
P2=1
P3=1
P4=0
P5=0
C1=4
C2=0
C3=8
C4=0
C5=10
C6=3
C7=0
C8=0
C9-0
C10=N
C11=0
C12=4
C13=0
C14=2
I have built many e-bikes over the years but never used a HESC motor
The motor is the only thing I haven't changed
Any advice would be greatly appreciated
Thank you
Dylan

 

[Nealh]

Tbh I don't see a need for a throttle with a 22a controller or that case any controller, what ever the reason just omit it and reset the C5 to max.
06 is a phase error code ,so connectors or even a bottle neck for the current to flow. Are the controller wire gauge thinner then the motor phase gauge or maybe the connectors are crappy.

 

[AntonyC]

Based on forums (no experience of KT, sorry) but does anyone else think it sounds a bit like a controller running sensorless?

You could disconnect 1 or more hall sensors, perhaps by butchering the old wiring, and see if it behaves much the same near stall speed. If so:

1) if with old wiring it works OK with the halls in circuit, maybe the new wiring is differently wired or a bad plug as Nealh said.
2) "Checked the motor halls resistance between phases" hopefully you meant compared resistance between phases but look for pulses too as the wheel turns.
3) it might be worth trying to check whether the KT controllers can handle the HESC motor's timing i.e. 60 degree or 120, see
endless-sphere.com/forums/viewtopic.php?f=2&t=957

 

[saneagle]

HESC motor can't run at 48v and 22A. Your gears will strip, like what happened to the other guy recently. Stick to 15A.

HESC motor has a very high internal speed. You're probably getting a commutation issue. Try setting P1 to a much higher number, or if you're lucky, you have L parameters where you can set L2 to 1 to double the number for high-speed motors.

 

[dylan]

thank you guys for your sage advice
much appreciated
I will investigate further at the weekend

 

[dylan]

So guys after much playing with settings & swapping controllers etc I could not resolve the error, but I have a work around that I can live with. I used the larger 22A controller (rather than the 15A) in & reduced the current by 50%. This stops the cut out from standstill problem & is just enough power to live with.
At least I will get much longer range now - every cloud & all that...!
thank you all once again for your advice