Help! My Controller is Out of Control

[Beagle123]

I just bought this controller:

http://www.tncscooters.com/LB37.php

I hooked-up the motor to the yellow/blue wires. I hooked-up the throttle to the blue/black/red plug wires. Then, when I hooked up the battery, the motor went full throttle, leaped off the table, bent the axle of my CVT transmission, and landed in a pile while luckily unplugging itself in the crash.

I brushed myself off, and tried again. I disconnected the "lock" connection. This is essentially an on/off switch. So I turned the controller off. Then I disconnected the throttle completely. This was labeled as "deraileur." The motor was already disconnected. So nothing was connected. When I connected the battery again, I tested the motor plug, and it showed that exactly 52 volts were across the motor connection. This seems like a short circuit of some sort. My other controller (36v) will show a max of 25 volts to the motor. I would expect this controller to show a max voltage of maybe 40 volts to the motor at full throttle. It seems like it should never blast the full voltage.

What did I do wrong?

Here are my thoughts:

I correctly connected the motor to the yellow/blue plug as in the wiring diagram, and the motor is reversable, so it can't be backwaards. I think that eliminates the motor connection as the cause of the problem.

I connected the battery wires correctly too. They were the big red and black wires. Red to red, black to black. That shouldn't be a problem.

When I connected the throttle it looked very straight-forward-- I connected black to black, blue to blue, and red to brown (similar). However, I didn't verify that these connections were correct using my voltmeter.

So it is possible that I had the motor wired to full throttle when I connected the battery the first time. That blast of power could have damaged the controller (?). I tend to think not because wiring it incorectly, would just make the controller be at full throttle, which is a normal condition. It should survive that.

I think its correct to assume that the controller is broken if you connect the battery to it with everything else disconnected, and the motor connection shows 52v (exact voltage of battery).

Fetcher, are you out there?

 

[safe]

If you are like me and have bought throttles from TNCScooters then you might have a throttle related issue. I've gone through something like 3-4 of them already... they are $7 and don't have the best components in them. One time I managed to destroy one just by touching a soldering gun to two of the wires at the same time. The throttles use this nearly microscopic Hall Effects Sensor in them and they short out easily. I've had good luck recently... but I have two backup throttles just in case. If I've understood your problem it might be that the throttle is stuck wide open...

 

[Beagle123]

Yes, I did buy my throttle from TNCScooters. It may have been the original problem, but now I've disconnected everything from the controller, and I still get a 52v reading to the motor with NOTHING connected including the lock (on/off) switch.

I'm pretty sure something is very wrong with my controller.

 

[safe]

It may have been the original problem, but now I've disconnected everything from the controller, and I still get a 52v reading to the motor with NOTHING connected including the lock (on/off) switch.

If your throttle is completely disconnected and you connect your motor and battery wires correctly it should do nothing. It does sound like a short of some kind. Is this a new controller? Never used before?

Fechter is the guy that knows the guts of these controllers, I don't, but if your throttle is completely disconnected and you are SURE the motor and battery wires haven't been connected wrong somehow then it sure does sound like a controller that is fused wide open.

Could it hurt to try swapping the motor and battery wires around a little? If it's already fried things don't get much worse...

 

[Beagle123]

Yep, its a new controller. I think it was faulty to start with. It would explain everything. When I first hooked it up, it would have caused the motor to go full throtle. It seems its just wired wrong. I think I'll have to get a new one. I may just take it apart out of curiosity.

Thanks for the help safe.

Also, I'd like to get your advise on a frame I'm designing. I'll make a post later.

 

[fechter]

It sounds like the controller is shorted internally. These controllers are not famous for stringent quality control. I'd guess you did everything right but got a defective controller.

If you have an ohmmeter, disconnect everything and measure between the battery negative wire and the motor negative wire coming out of the controller. Reverse the probes and measure again. If you get a low reading both ways, it's toast. It should be high (over 100k) in one direction.

Got warranty?

 

[xyster]

For $5 more you could get the better YK42-4:
http://www.tncscooters.com/YK42-4.php

http://tncscooters.com/partsdb.php?type=ES

Some other people here (safe?) are using it...

 

[safe]

For $5 more you could get the better YK42-4:
http://www.tncscooters.com/YK42-4.php

http://tncscooters.com/partsdb.php?type=ES

Some other people here (safe?) are using it...

I'm using the YK42-3 (36 Volt) and it's very good. I own the YK42-4 in the 100 Amp current limited version and hope to use that as a basis for my future Motor Current Limited bike. (the one I'm building now) If I can get away with 60 amps or 70 amps boost while not overheating the motor then I'll be thrilled. But I expect to be closer to 40 - 50 amps... only testing will show how much boost I can run. Also the effectiveness of my air cooling will be a big factor... so having up to 100 amps to experiment with will be nice.

 

[Lowell]

Be careful when working on your bike...

http://www.r1-forum.com/forums/showthread.php?t=204630

 

[fechter]

Be careful when working on your bike...

http://www.r1-forum.com/forums/showthread.php?t=204630

Oh BARF! that's ugly. Bet he doesn't do that again.

 

[Lowell]

I have a tiny scar on my thumb as a reminder of what a 100W RC heli can do when it goes to full throttle while you're working on it. I wonder if a 1000W chain drive and sprocket would have enough power to shorten fingers?

 

[Beagle123]

In my situation the 1200 watt motor broke the axle of my CVT transmission is a split second.

Knowing my tendency to connect things wrong, I was standing back holding the wire out to touch it to the battery to test for any type of unexpected readtion.

Beleive me its powerful. The axle was 1/4 inch steel rod. I think it takes a lot of force to break it.

That's some crazy stuff from that guy. You have to wacth out when wearing long sleeves too. If they hang down, they can catch in things too.

I'm glad I'm a coward.

 

[Beagle123]

I almost forgot to tell y'all taht I ordered another controller. That one was a dud.

 

[Beagle123]

If I can get away with 60 amps or 70 amps boost while not overheating the motor then I'll be thrilled. But I expect to be closer to 40 - 50 amps... only testing will show how much boost I can run. Also the effectiveness of my air cooling will be a big factor... so having up to 100 amps to experiment with will be nice.

Safe, I think you'll need some serious cooling. My 1020 motor that both of us use now has been running pretty hot when the weather gets warm. If I run about 20 amps through it at 36v, it heats up hot enough that you couldn't hold your hand on it for too long. I don't know what a safe operaating temperature is.

Notice that our new motors (1200 w 48v) have the same ventilation system--almost none. And we can expect the new motors to generate 1 1/2 times more heat.
Please keep me updated.

 

[safe]

Safe, I think you'll need some serious cooling. My 1020 motor that both of us use now has been running pretty hot when the weather gets warm. If I run about 20 amps through it at 36v, it heats up hot enough that you couldn't hold your hand on it for too long. I don't know what a safe operaating temperature is.

Well, it's hard to know in advance how much heat is going to be created. Don't forget that the formula for heat is:

Heat = ( ( Amps ) ^ 2 ) * ( Resistance )

...so if you increase the voltage you don't add any extra heat while getting more power. So switching from 36 volts to 48 volts should not be a big problem. When I switch from battery current limiting to motor current limiting it automatically chops the low end heat down to a very low level... so right there that's cooling the motor off a great deal. Add to all this the idea of forced air cooling like Fechter uses and this is supposed to nearly double the heat dissipation rate.

So when you jumble all these parameters you end up with an unknown practical upper limit to how much current (and heat) you can run. It would be awesome to have an adjustable boost limit so that every once and a while you might decide to go for a speed attempt at, say, 100 amps for a short period of time. Afterwards you turn the boost down to a more practical 40 - 50 amps. You also drain your battery really fast at 100 amps, so it's also a question of range.

I'll only know when I get to the point of testing...