Electric roller door motor help.

[whitebeetle]

Hi , Can anyone help.
Got an electric roller door , the door motor has been hit by a forklift truck and has damaged the wiring to the motor. The motor has no terminal box , the terminal cables just come off the windings directly. I have dissasembled the motor and found only w1,w2 winding still connected , i found this coil to have a resistance of 9 ohms. The other 4 wires (u1,u2,v1,v2) were all ripped out. however using my meter i found the other two coils (measured at 9 ohms) and reconnected the wires.

So in short i have three coils,u1-u2 , v1-v2 and w1-w2 all with 9 ohm resistance , however if i test between u1-v1,v1-w1 or w1-u1 i also get a reading of 36 ohms (i would have expected this to be a megaohm reading).

Anyhow , i have reconnected the motor but when i press the control for up and down the motor always goes in the same direction !

Is there anything i can have got wrong on the motor wiring or is there something wrong with the control ?

Any help is very much appreciated.

 

[Knobhead]

"Is there anything i can have got wrong"

Employing the forklift griver?

 

[Marvo]

The motor must be supplied from a control box that contains contactors. Check if any contactors are welded in the closed position. The answer to your problem will probably lie in that control box somewhere.

 

[Specialist]

As Marvo said: Quite likely blown the contactor / controller.

 

[Knobhead]

The fact you’re getting a reading between U1, V1, W1 would indicate some damage to the windings. The resistance is to high for it to be a reading of a star connection. I would suggest a new motor and protect it from the FLT. (Or shoot the driver).

 

[Specialist]

Thanks Tony: Think I need new eyes, just re-read the OP's post & saw the bit about winding resistances. My excuse is age & i'm sticking to it Lol.:wheelchair:

 

[Knobhead]

I’m old, so where’s the excuse?

View attachment 9066

 

[Specialist]

:rofl:

I’m old, so where’s the excuse?

View attachment 9066

:rofl:

 

[silva.foxx]

...the terminal cables just come off the windings directly. I have dissasembled the motor and found only w1,w2 winding still connected , i found this coil to have a resistance of 9 ohms. The other 4 wires (u1,u2,v1,v2) were all ripped out. however using my meter i found the other two coils (measured at 9 ohms) and reconnected the wires.

So in short i have three coils,u1-u2 , v1-v2 and w1-w2 all with 9 ohm resistance , however if i test between u1-v1,v1-w1 or w1-u1 i also get a reading of 36 ohms (i would have expected this to be a megaohm reading).

Anyhow , i have reconnected the motor but when i press the control for up and down the motor always goes in the same direction !

Your reconnected coils; are they correct polarity now?

A useful test if required: View attachment Motor tails identification.pdf Try this first if you can.


You say the motor is working, so not tripping and not running long enough for overload, etc...

Are we to take it there's seven wires up to the motor (U1/2, V1/2, W1/2 and E) from the control box?

Is the direction control via reversing contactor?

Is the motor noisy?

Any motor data ie. star or delta?

 

[Knobhead]

Have a look in the “electrical therory” thread in the stickys. I posted a method for testing the polarity of motor windings. But with the readings you give for the inter-winding resistance I’m still favouring a short in the windings.