motor testing

[robl2k]

Hi guys n gals,
I've got a working 36v battery, a possibly faulty control box and a 36v 250w hub motor which should be working.
I just want to test the motor before proceeding.
It's got 3 thick blue, green and yellow wires and a further 5 thin wires of the same colours plus red and black.
Is it possible to put 36v through any 2 of the thicker wires to test the motor?
Thanks for any advice.

 

[Alan Quay]

Hi guys n gals,
I've got a working 36v battery, a possibly faulty control box and a 36v 250w hub motor which should be working.
I just want to test the motor before proceeding.
It's got 3 thick blue, green and yellow wires and a further 5 thin wires of the same colours plus red and black.
Is it possible to put 36v through any 2 of the thicker wires to test the motor?
Thanks for any advice.

No, that's not how it works. The motor is a 3 phase DC unit, and needs a controller to work.

Have you got a multimeter?

 

[robl2k]

Wow thanks for the super prompt reply.

Yes i have a multimeter.

 

[Alan Quay]

So, first things first.

How many volts from battery, and can you confirm thats feeding to the controller?

 

[robl2k]

I've actually got 2 batteries which both work fine with another electric bike (36v 800w).

I'll have to dig out the possibly faulty controller for the 250w wheel.

Could i test it with the controller from the working 800w machine?

Thanks again for your help

 

[Alan Quay]

It a important to test this thing through in a logical manner.

Firstly, it's important to know how many volts are coming out of the battery, and if its getting to the controller.

 

[robl2k]

I've located the controller.

Brushless dc36v
Model: kt36zws-xfklcdsm
Min Volt: 31 +/-0.5v
Max current: 14 +/-1a
Speed set: 1-4.2v
Brake input: low level

It's got the following block connectors:
Lcd display
2x brake
Speedo
Throttle
5 wire block with thin blue, green, yellow, black, red (goes to motor i assume, as I've previously removed the connector on the motor wire. I'll try to find it or fit a new one.)

And 5 loose thick wires: blue, green, yellow, black, red

I assume the thick black and red wires go to the battery and the others go to the motor?

I think the battery voltage changes depending on charge. I'll check but i think it's around 37v

 

[robl2k]

There's another 3 pin connector for the pedal controller i think (thin red, yellow, green)

 

[robl2k]

The battery gives 39.x V one way round and -41.x V the other, which is odd.

Can i safely connect it to the controller without anything else connected?

 

[Alan Quay]

The battery gives 39.x V one way round and -41.x V the other, which is odd.

Can i safely connect it to the controller without anything else connected?

There's something wrong with your meter if it's giving different readings for for pos/neg values, but it suggests the battery is good enough for testing.

There's no point connecting battery to the controller until you have at least:

Controller connected to motor thick wires (phase wires)

Some form of control signal - throttle or Pedal sensor (PAS).




The thin wires from motor are for the hall sensors. Your controller/motor may or may not require them. If you can, connect them colour to colour.

Then connect power, but don't give it full throttle at first.

 

[robl2k]

Ah, i thought the meter might be on the way out.

I'll try what you suggest with and without the hall sensors.

I should have a result in the next couple of hours.

 

[robl2k]

Mixed news.

The lcd display works.
But no signs of life from the motor.
I tried without the hall sensors and then with.
Can i try with my working controller from the 800w system?

Or how do i get a compatible controller?
I read elsewhere that some work without the hall sensors and you seemed to suggest the same.

 

[Alan Quay]

Mixed news.

The lcd display works.
But no signs of life from the motor.
I tried without the hall sensors and then with.
Can i try with my working controller from the 800w system?

Or how do i get a compatible controller?
I read elsewhere that some work without the hall sensors and you seemed to suggest the same.

You should be ok with the 800w controller, as long as you only run it briefly, gently and under no load.

Some controllers/motors will run without sensors.

I assume you are using a throttle? Have you checked that its working?

 

[robl2k]

I used the throttle. I assume it works. I can try the known working one.

I didn't have the PAS connected. Would that matter?

I'll try the 800w controller.

Thanks again for all your help.

 

[robl2k]

Latest developments:

I connected the 3 thick wires, of the questionable motor, to the existing functional system, without disconnecting the hall sensors of the known working motor.

The questionable motor ticked and moved when i applied a little throttle. I then disconnected to avoid damage.

I think this is good news for the motor?

I also voltage tested the 3 thick wires from the questionable controller with throttle applied and got nothing across all combinations.

It could be the throttle but the working throttle has more wires for it's led power meter (green, orange, red leds).

I'll check for similar colours in the throttle wires.

Can i mimmick a throttle signal or open it and short the wires or something similar?

I think I'll get a new controller?

This is great news and will help a fledgling eco bike business.

I have plans to clean London air with foldable electric bikes which go on train, tube, tram and bus, when necessary.

Where abouts are you?

 

[robl2k]

Slight change to the above.

Upon reconnection, although the questionable motor ticked and occasionally twitched when throttle was applied, it barely moved.

When i disconnected the hall sensors from the known working motor and applied throttle the (no longer?) questionable motor started to rotate.

I disconnected a 2 wire connection to the known working throttle and it still works minus the leds.

Which leaves me with 5 wires (in 3 and 2 wire connectors) instead of the 3 wires for the questionable throttle.

It could still be the throttle.

Perhaps I'll get a new throttle and controller?

 

[robl2k]

A couple of updates:

There was no sign of life from the newly-working motor using the known working throttle with the questionable controller by connecting white to white, red to red and black to blue.

Although i didn't have the hall sensors connected.

The known working system works without the hall sensors connected.

Can any damage be caused or could there be any other ill effects from using without the hall sensors connected?

 

[Alan Quay]

A couple of updates:

There was no sign of life from the newly-working motor using the known working throttle with the questionable controller by connecting white to white, red to red and black to blue.

Although i didn't have the hall sensors connected.

The known working system works without the hall sensors connected.

Can any damage be caused or could there be any other ill effects from using without the hall sensors connected?

You should be ok to run without hall sensors.

 

[robl2k]

I've just realised that I don't actually know the wattage of the motor or controller.

There's plenty of 350w controllers on ebay and several 250w.

I'm not sure which to get.

Can i measure the motor wattage?

Or can it be ascertained from the information on the existing controller (see top of thread)?

 

[Alan Quay]

A 14a controller is normal for 250w motor.

Most 250w motors can take a bit more. I've run them up at about 18-20a (around the nominal 350 watt mark) but obviously you risk wrecking it. I've not broken one yet.

The other option is to take a 250w controller and 'shunt kid's it to get a bit extra current. The advantage is that you can do a bit at a time You will need a watt meter to see what's going on.