Motor or controller fault pls help??

[my.motion]

Hi Team,

My custom made ebike (front wheel motor, 48v 1kw) has developed a fault as described below:

- When switched on, the motor seems to vibrate but is not moving.
- I can get the motor to move/rotate only when I lift the bike up and do not apply any load to it. As soon as the wheel touches the floor it stops rotatingm only vibrating noises can be heard
- I tried the controller on a 36v Milan 2 motor 288W bike but to no avail, when the controller connected to the 300w milan 2 bike it just makes vibrating noise and doesn't move the motor

Ok this is the kit I have

1- Milan2 bike (36v SLA battery, 288w motor, 36v controller)
2- 48v 15A Lipo battery
3- 48v Controller
4- 48v 1kW Front wheel motor
5- Voltmeter

The milan2 to bike, is not working properly due to it not been used for along time.

Any help and suggestion to get me on the road will be highly appreciated

Thanks and Regards

Motion

 

[Mussels]

I'm not an expert but it sounds like a sensor wire problem.
Was it working before?
Have you disconnected it since it last worked?
how many wires go to the motor?

 

[my.motion]

I'm not an expert but it sounds like a sensor wire problem.
Was it working before?
Have you disconnected it since it last worked?
how many wires go to the motor?

Yes it was working before, and still works but only if I lift the front wheel and don't apply any load. The motor has connection shown below


I have disconnected the controller since then to try it on another bike

 

[NRG]

Could be hall sensor failed in the motor, poor hall sensor connection or failed drive cct for one of the phases in the controller.

 

[Mussels]

I have disconnected the controller since then to try it on another bike

Was it disconnected before or after the fault developed? The hall sensors connect with the white connector in your photo and it's quite possible one of the spades has come loose, have a good check.

 

[my.motion]

Was it disconnected before or after the fault developed? The hall sensors connect with the white connector in your photo and it's quite possible one of the spades has come loose, have a good check.

I have disconnected after it failed to try it on my milan2. I will reconnect today and see what happens.

I am just wondering why does the wheel stop rotating when load is applied?

What are the functions of these hall sensors?

Thanks

Motion

 

[Mussels]

I have disconnected after it failed to try it on my milan2. I will reconnect today and see what happens.

I am just wondering why does the wheel stop rotating when load is applied?

What are the functions of these hall sensors?

Thanks

Motion

The sensors tell the controller what position the wheel is in, the controller then sends power down the correct wires to turn the wheel. If the sensors dont' work properly then the power isn't applied correctly and the motor loses most or all of it's strength.

 

[Andrew harvey]

This sounds very much like a sensor/ sensor signal problem.
You can test the motor windings with a multimeter.
Set it to ohms, measure the resistance between the fat cable, (with the controller disconected of course), you should get a reading of around 0.5 to 1.5 ohms between these motor leads.
To test the Hall sensors on in the motor is more tricky, you have to apply a voltage to the thin red and black motor cables, a small 3 to 9 Volt battery pack is ideal, positive to the red, negative to the black, then with a multi meter set to low volts DC measure the voltage between the positive supply and the hall sensor return cables, then with your third hand spin the wheel. So if you start with say the green hall sensor cable connected to the meter, you should see a voltage between 1v and the voltage of your battery, turn the wheel, this voltage should change as the wheel moves, going from a low voltage to a high. Repeat this with the other sensor cables.
If your wheel is geared with a freewheel turn it backwards.

 

[Leesome]

Reads like you've dropped a phase from the out-put of the controller. This could be a hub issue? Install the controller on another bike, if it works then your hub is the issue, if not then most probable its the controller.

 

[my.motion]

Thanks

All,

Thanks for your input, I removed the controller and rewired the motor/sensor and hall wires. The three colored motor wires melted at the connecting ends, what causes this and any suggestion on how to prevent this please? The five hall wires were rewired as well.

I am still using the same connectors but have a feeling they will melt again

Thanks all for you input

Regards

motion

 

[Uningles]

Do you still have the problem?

If so, this actually sounds like one, or more, blown FETs inside your controller. This would be borne out by the test with your alternative motor, assuming you wired it correctly.

If your wires were melted at the time that you spotted the fault, then it is likely that your motor drew too much current for the controller, as a result of some fault, or excessive (and perhaps prolonged) loading.

FETs can be replaced, if you're handy with a soldering iron - assuming the board, or other components have not been damaged. Other than that, new controllers are not overly expensive (compared to some other bicycle components).

 

[my.motion]

Do you still have the problem?

Hi Uningles,

Thanks. The problem is sorted now, I am planning to replace the 3 motor wires connector with 3 pin XLR connectors. I hope these will be better than the bullets connector

Regards

Motion

 

[Andrew harvey]

Anderson power poles cost a few pounds from RS Components but carry upto 30 amps and can be phased.
Melted terminals normally indicate a poor connection, rather than the device taking to much current, I was an electrician for 30 years, so I've seen many examples of this.
Anderson | Connectors | Accessories | Connector Accessories | High Current - Anderson Power |1327G6
You will need to order the blades seperately.

 

[NRG]

Another recommendation for the Andersons, great connectors....

 

[my.motion]

NRG, Thanks. I will try an order these connectors