Help! My next project

[Benjahmin]

How fast was one ascending when the controller got hot ?

Very variable , but manged to keep it above 8. But these are long climbs on a warm day.

Start by checking that the motor connector is in all the way to the line.

First thing I did.

I'm thinking that, because the speed reading suddenly stopped working, that something in the controller has gone. It sounds like it is misfiring as the motor not deepened and gave more vibration.

 

[saneagle]

Very variable , but manged to keep it above 8. But these are long climbs on a warm day.

First thing I did.

I'm thinking that, because the speed reading suddenly stopped working, that something in the controller has gone. It sounds like it is misfiring as the motor not deepened and gave more vibration.

The speed reading comes from the speed sensor. If there's no speed signal from it, or if you have P1=0, the controller will take the speed signal for the LCD from the motor halls, which is why you have to enter the number of magnets and reduction ration. In that condition the speed would show zero when free-wheeling. That wouldn't have any affect on the operation of the motor.

On my Q128, the speed sensor packed up quite early on, so I've always used an external wheel magnet type.

 

[Benjahmin]

I have P1=128. Speed display did work but stopped mid ride. There is no speed sensor connected, never has been.
So, as you say, it must be getting the speed signal from the halls. As it was working fully but is not now (and no settings have been changed) would this indicate there's something faulty with the Halls?

 

[Benjahmin]

Bike has had several hours to cool down now. I've just run it up and down the village (flat road) and everything was working OK, including the speed display.
I really am thinking it may be heat related.
Think I may need to get more ventilation which is difficult whilst also weatherproofing it.

 

[saneagle]

I have P1=128. Speed display did work but stopped mid ride. There is no speed sensor connected, never has been.
So, as you say, it must be getting the speed signal from the halls. As it was working fully but is not now (and no settings have been changed) would this indicate there's something faulty with the Halls?

Q128 has an internal speed sensor, but maybe the magnet has come unglued.

 

[Benjahmin]

Yesterdays ride involves climbing out of the valley I live in, going down into the next then climbing out of that before going down to the coast.
The second climb I noted as 1.6 miles from bottom to flat (ish) top. Variable gradient with the first 6-800 yards being around 1:6. The climb out from the coast (via less severe gradients) is a very long intial climb of around 4 miles. Very variable inclines so speed varying from 8 to around 12/13.
This is alot of slow speed climbing in level 5, trying to keep above 8mph.
So I decided to do some maths.

Controller is T09S set at 20A max.
Motor is 48v 328rpm running at 36v giving 246rpm.
Measured wheel radius is 13.25" giving 83.25" circumference.
So:
@246rpm this gives a motor top possible speed of 19mph
Therefore 16mph is .842 of top speed
10mph is only .526 of top speed
8mph is 0nly .421 of top speed.

So, do I have the wrong motor? From the maths and given the 16mph restriction, it seems it never gets near to magnetic saturation.
Given the long climbs that one has to do to get a decent length of ride around here, is the length of time spent in low back emf conditions just too much for the system? Too much heat being produced?

I'm starting to think I need a 201rpm 36v motor.

 

[Nealh]

If the T09S got very hot ( too hot to hold or touch for more then a brief nano second) then one would say thermal cut out where mosfets reached their max op temp.

I had the same issue with T06S and why I opted to for the T09S and since not had the issue on the same rides.
My AKM128CST is 36/201 , I run it at both 36v & 44v .

 

[Benjahmin]

Thanks Nealh, those are the lines I'm starting to think down.
At the moment operation is erratic. This morning I went to the next village shopping, about a 4 mile round trip.
It let me down badly crossing a main road at an offset cross. Approach to junction is downhill so no assist. Exit is up camber onto main road then up an off ramp. Pulled out onto main road - nothing- no assist, no throttle. Didn't kick in until I was onto the off ramp. Unpredictable and bloody dangerous.

 

[Sparksandbangs]

Thanks Nealh, those are the lines I'm starting to think down.
At the moment operation is erratic. This morning I went to the next village shopping, about a 4 mile round trip.
It let me down badly crossing a main road at an offset cross. Approach to junction is downhill so no assist. Exit is up camber onto main road then up an off ramp. Pulled out onto main road - nothing- no assist, no throttle. Didn't kick in until I was onto the off ramp. Unpredictable and bloody dangerous.

How can it be overheating when up you are on a downhill with no power being supplied to the motor? I'm thinking it is some weird software glitch.

 

[Benjahmin]

My thoughts exactly.

 

[saneagle]

My thoughts exactly.

Software either works or not. It can't glitch. There are only two possibilities: 1. You have a connection fault; 2. Temperature is going too high.

Neal, what happens when the temperature goes too high? Does the LCD show anything?

My motor is faster than yours. I still stick to the 15 mph limit. I climb very long hills at 8 mph. Nothing has ever over-heated. Maybe your hills are steeper than mine. I'm roughly 95kg. How heavy are you?

Did you check that your phase wire bullets are all the way in and tight?

 

[Sparksandbangs]

Software either works or not. It can't glitch.

I seem to remember Boeing having the odd one or two in the recent past

 

[Peter.Bridge]

Software either works or not. It can't glitch. There are only two possibilities: 1. You have a connection fault; 2. Temperature is going too high.

Neal, what happens when the temperature goes too high? Does the LCD show anything?

My motor is faster than yours. I still stick to the 15 mph limit. I climb very long hills at 8 mph. Nothing has ever over-heated. Maybe your hills are steeper than mine. I'm roughly 95kg. How heavy are you?

Did you check that your phase wire bullets are all the way in and tight?

When the temperature goes too high on mine, (KT) the power stops completely or greatly reduces , the display looks normal

 

[Woosh]

sorry for the diversion, @saneagle this case is why I have not sold KT controllers and stick with Tongsheng, Bafang and Lishui. When you have the facilities to configure the controller to your own liking, you may run into complications like overheating, intermittent faults. I can't see that the extra sales of a £40 controller are worth the extra cost of support.

 

[Benjahmin]

Bullets were the 2nd thing I checked.
When it wouldn't work (crossing the main road), there was nothing. Display was still on showing assist level but no mph.
Can only be the pas can't it? No pas, no assist or throttle. Pas is one piece so, apart from the plug at the controller, there's nothing I can check.
Neal, what maximum current do you have set?

sorry for the diversion, @saneagle this case is why I have not sold KT controllers and stick with Tongsheng, Bafang and Lishui. When you have the facilities to configure the controller to your own liking, you may run into complications like overheating, intermittent faults. I can't see that the extra sales of a £40 controller are worth the extra cost of support.

Ouch ! Would have bought one of yours but you didn't want to supply without battery.

 

[Benjahmin]

When the temperature goes too high on mine, (KT) the power stops completely or greatly reduces , the display looks normal

That's what happened yesterday, like it had gone into some sort of limp mode.

 

[Sparksandbangs]

But how can it be overheating when it hasn't been doing any work? It's happening after a long downhill section with no assistance.

If someone would like to explain their thought process on how this is occuring I'm happy to reconsider.

 

[Peter.Bridge]

I've only hit this problem going up very steep hills, slowly (<7 mph) in max assist level.

 

[Benjahmin]

As explained above, there were some long climbs and it was during one of these that the cutout problem first occured.
I'm starting to think that cumulative heat has done some damage to the electronics. The intermittant nature is puzzling and would seem to point to a connection issue, but I can't find anything.
Bullets look and feel fine but I am thinking of soldering.

 

[Peter.Bridge]

As explained above, there were some long climbs and it was during one of these that the cutout problem first occured.
I'm starting to think that cumulative heat has done some damage to the electronics. The intermittant nature is puzzling and would seem to point to a connection issue, but I can't find anything.
Bullets look and feel fine but I am thinking of soldering.

@Nealh has said it happened to him and permanently damaged the controller