Controller overheating issue

K

Kuppenhorst

10 mW
Joined
May 28, 2019
Messages
27
Hi,
I have a problem with my latest build.
Here's the setup :
26" mtb basis
52v 30ah triangle battery
48v 1000w rated rear hub motor
11A/22A max square wave controller
LCD3 Display
Pas and thumb throttle
Pas is always on and I'm pedaling all the time
Throttle is only for starting and crossing roads etc.
I live in the Netherlands and we ain't got steep hills here.
I had everything running fine but then I decided to go with a more powerful kt sine wave controller 15A/30A max.
The new controller run smoothly and works just fine until it's getting warm and than hot.
The problem is when the motor /controller cuts off. When I switch off and switch on again everything works again. The lower the pas level the quicker the cut off comes. When I use throttle the whole time there's no problem. The same goes for pas level 5. Using the max current the controller won't cut off. Btw the motor runs smooth and silent, so I don't think it's the motor phases.
May be I need to change a display setting because I'm using a sine wave now? May be someone can point me in the right direction.
 
if contorller is overheating either it's not getting airflow or the hall/phase combo is wrong which usualy also makes the motor hot
 
Thanks for the reply. The motor is at worst getting a little bit warm. May the pas is broken and gives some discrepancies to the controller. I'm using the ktv12l.
 
I don't think you have an overheating issue. What you are describing is very similar to what I experience on one of my bikes that I have determined to be an over voltage cut off from the controller above ~56 volts. The clue is that it happens at low power levels but not at high. At high power you have just enough voltage drop to keep the controller happy. At lower power levels with a fully charged 52v battery after a few minutes run time my controller decides it has had enough and cuts power. I deal with it by releasing the throttle momentarily and power returns for a while. This continues until the pack voltage drops below ~56 volts and the problem doesn't return until the battery is recharged.
I was told that the KT sine wave controllers are set to recognize specific voltage ranges around
36 v, 48 v, and 72 v batteries. The 52 volt or 14s battery falls between the expected ranges and the controller sees a problem.
I don't know of a fix and have basically just learned to deal with it.
 
Problem is it's getting really hot. I can't hold it with my bare hands because it's too hot. Interesting point though - the voltage issue. Yet in the beginning the controller worked just fine and I didn't have any issues with neither overheating nor power cut offs.
 
It should not be getting hot at those power levels. Something is wrong. There are several possibilities. I would first suspect the Hall/phase wiring. The new controller may have a different color matching for the motor wires. You may need to swap some wires around to get it right. Some controllers have a "self learn" function that does this. Older models you just have to do trial-and-error to get it right.

Here is a really old tutorial on how to match the wires.
https://endless-sphere.com/forums/viewtopic.php?f=16&t=3484

There are some newer, more updated instructions somewhere around the forum.
 
I found that the new pas ktv12l was broken. I changed it to a conventional one. Then everything seemed to be working fine except for the heating of the controller. But the motor didn't cut off. Today I went for a long ride and rode at a speed of ca. 30km/h pas level 2. After like 30 minutes the motor started cutting off again and I had to switch off and on again to continue my journey.
Now I have a question about the phase wire testing. I already have the xls file from the other thread. I just wanted to know if the motor can just run fine and still have the phase wired incorrectly.
 
Kuppenhorst said:
Now I have a question about the phase wire testing..... I just wanted to know if the motor can just run fine and still have the phase wired incorrectly.
Click to expand...

Yes. it's called a false positive. It doesn't happen with every motor or controller, but it is possible for one of the incorrect combos to function to various degrees. Some motors stutter a bit, others seem smooth as silk. For those, the only real symptoms are high current draw at low loads, over heating controllers, and possibly higher than normal top speed when the motor is free running. Check your amp load with the wheel in the air and compare that to the motor's no load amp specs.

Or, you could just have a bad controller.

Or, you could have a short in a phase wire to your bike frame. if the frame of your bike is a higher resistance path than the phase wires, it might not cause a noticeable motor problem, but still be shorting out the controller and causing it to over heat. That you have less heating when you are at full throttle and the phase wires have lower resistance through the FETs could be an indication of this kind of short. In effect, you might accidentally have created an HGR Protection System. (High Resistance Ground)
 
That's gonna help me out. I think I can rule out a short but the 1st part of your answer is exactly what I have. Is there a possibility to have more than one false positive?
 
Kuppenhorst said:
That's gonna help me out. I think I can rule out a short but the 1st part of your answer is exactly what I have. Is there a possibility to have more than one false positive?
Click to expand...
Yes. There are 36 possible combinations of wire colors. 6 of them should make the motor run properly (3 forward, 3 in reverse). The other 30 combinations can do what you are describing.
 
Just to be sure I understood everything. So I have 1 of those 3 properly forward spinning combinations but not the right one?
 
Kuppenhorst said:
Just to be sure I understood everything. So I have 1 of those 3 properly forward spinning combinations but not the right one?
Click to expand...

No. the 3 forward spinning combinations will all behave identically, just the colors match differently. Sounds like you have one of the other 30 that makes the motor spin but grossly mis-timed.
 
I'm not done testing yet but I can confirm that the phase wires are mixed up. I didn't find the right combination yet but I know the issue. Thanks for the support to everyone who responded. Great forum!
 
Kuppenhorst said:
I'm not done testing yet but I can confirm that the phase wires are mixed up. I didn't find the right combination yet but I know the issue. Thanks for the support to everyone who responded. Great forum!
Click to expand...
0fe83776-2fc1-40ea-ae11-3d5c068a521a.png
 
https://endless-sphere.com/forums/viewtopic.php?f=14&t=98771&p=1465686&hilit=Fix+charger#p1457184

https://endless-sphere.com/forums/viewtopic.php?f=14&t=98771&p=1465686&hilit=Fix+charger#p1457197
 
Kuppenhorst said:
Just to be sure I understood everything. So I have 1 of those 3 properly forward spinning combinations but not the right one?
Click to expand...

3 combinations out of 36 will give you 3 true positives IN FORWARD.
Ex: abc+BCA, bca+CAB, cab+ABC

And 3 combinations out of 36 will give you 3 true positive IN REVERSE.

The 30 combinations out of 36 will give you false positives (in reverse and forward), were motor can either stutter, run rough, vibrate, not do anything, run twice as fast (but with no tork under load). Only solution is to try out all 36 combinations and take note like i did (see my post links above).
 
Thanks for the handy replies. In the mean time I've been testing the possible combinations and found a seemingly good one. But... After a successful test drive of approximately 25km the controller was still very warm. The next time I wanted to ride I got the info 03 error message on the lcd3. I changed to a sensor less controller and everything works fine since. I assume that the halls were almost broken and gave some weird values to the controller so it got hot. I have to admit that I didn't went to a long test ride so that's only what I assume.
 
Today I went to a test ride of approximately 30km. While being on about 30km/h with pas level 2 the e motor cut off one time when I was riding slightly downhill. For the rest of the time everything was fine. The controller was at least very warm. It's a sensorless square wave 48v 22A(max) controller. What can I make of this? Is it just motor running in an inefficient rpm zone? Or is it broken? I don't know exactly what motor I have. Only that I it's a 500w 36v/ 1000w 48v motor.
 
Kuppenhorst said:
Today I went to a test ride of approximately 30km. While being on about 30km/h with pas level 2 the e motor cut off one time when I was riding slightly downhill. For the rest of the time everything was fine. The controller was at least very warm. It's a sensorless square wave 48v 22A(max) controller. What can I make of this? Is it just motor running in an inefficient rpm zone? Or is it broken? I don't know exactly what motor I have. Only that I it's a 500w 36v/ 1000w 48v motor.
Click to expand...

What kind of riding are you doing when the problem occurs? Your original post said there are no hills, but your post above says you were going downhill, so I assume there's an uphill component to that as well. Also, how many watts are being drawn during most of your riding? Your controller should be good for 720 watts continuous, so if you're pulling more than that, there's going to be some heat along with that. Maybe provide some data points on watts being used in the lower PAS setting versus the higher ones.
 
On that 30km I have to climb like 70m max. That's all bridges across roads and highways, no hills. What I climb I go down on the other side. I'm always pedaling and on this specific trip the motor drew between 180 and 480w max, mostly around 280-320.
 
Kuppenhorst said:
On that 30km I have to climb like 70m max. That's all bridges across roads and highways, no hills. What I climb I go down on the other side. I'm always pedaling and on this specific trip the motor drew between 180 and 480w max, mostly around 280-320.
Click to expand...
What speeds when drawing 280 watts or 320 watts? How about PAS 5, where the problem doesn't happen? How many watts and what speed are you going under those circumstances?

Any power being consumed that doesn't translate to the bike's forward motion, is being dissipated through heat. It should show up in the data as well, which may help determine where the issue lies.

EDIT: Also, since the problem doesn't occur with the throttle, if you pedal as usual, but hold the throttle to provide 280 watts of assist, does the problem occur then? I don't use throttle only much, but was using it while my leg was healing. I noticed that although my motor is dead silent while riding normally, it doesn't like riding at low speeds, even though it's only pulling a few watts. It groans, sort of like a car engine lugs, at slower speeds. I'm guess the efficiency is pretty lousy too under those circumstances.
 
I can't go on pas 5 and max speed all the way as I have to cross some towns and villages. I think about 10km of the way I can go max. The controller draws about 1000w then. On pas 4 it takes approximately 500w+, pas 3 300w+, pas 2 250w, pas 1 150/180w.
Edit :
The problem occurs with the throttle too. I only didn't recognize it because I'm always pedaling.
 
Kuppenhorst said:
I can't go on pas 5 and max speed all the way as I have to cross some towns and villages. I think about 10km of the way I can go max. The controller draws about 1000w then. On pas 4 it takes approximately 500w+, pas 3 300w+, pas 2 250w, pas 1 150/180w.
Edit :
The problem occurs with the throttle too. I only didn't recognize it because I'm always pedaling.
Click to expand...

Does that mean that you're all the way back to it happens no matter what if you ride long enough, regardless of PAS setting or use of throttle? Or it always happens no matter what, except when using PAS 5 (or are you not sure because you can test it)? Sorry I tried reading through the thread again to understand the symptoms, relative to the description in the first post.

What kind of connectors are you using between the controller and motor hall sensor wires? Any possibility that the wires aren't kinked or damaged where they enter the motor through the axle? If something got damaged there when you switched thing out, you could test your old controller to see if the heating issue happens too.

The error code is pretty specific, and when I got that error, it was accurate, but took a while to figure out where the connection on one of the wires was intermittent.

Even though the battery seems sufficient, you may also want to monitor the voltage when it occurs by setting your LCD3 to display real time voltage.
 
I checked all cables and connectors and changed the motor phase connectors to the controller. Then it worked very shortly but then failed with the info 03 error message and running very rough. Probably the cable are damaged. I also found that the display was defective and malfunctioning after a ride through rain. When I tried to charge the battery for the next ride the controller became hot, probably because of the display switching itself on and off. So I changed the display too. Now I can ride without issues except for the controller still getting got. I ordered a replacement motor and will test the whole thing again with the new motor and the original 30A controller. I will then take apart the original motor and look for burned halls or whatever. I will report back.
 
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