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.

 

[silva.foxx]

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).

I can't fathom how you get 36 ohms! I can get near 3.6 ohms as a delta connection. Where were you measuring this 36 ohms and was it identical for each of the three tests? Were the wires open?

Any chance of it being a two speed motor?
Is it one of them high speed doors?
What is the manufacture and model?

What do you measure between U2 and W2? 18 ohms?

 

[i=p/u]

yous are good, how you know resistances of a coil.. im sure in time il be up there but for now how.

 

[Knobhead]

I get 6 Ώ. for delta. This is a purely resistive test so phase angles have no effect.

Rt = 1/((1/R1)+(1/R2))
where R1 = one winding
R2 = two windings in series.

Rt = 1/((1/9)+(1/18)) = 6Ώ

View attachment 9071

 

[Darkwood]

@Tony...... you seem to have deep down hatred of folk lift drivers lol can you enlighten us?
I partly rely on crap folklift driver to pay my wages they are a regular income for me so cant be shooting them more like ...Get that man a beer!:chillpill:

 

[Knobhead]

I’ve spent to much time repairing what they’ve destroyed. Walls demolished, pity about the distribution boards on the other side of it, the list is endless! As for roller shutter doors, I’ve lost count of the number wrapped around the mast.

BTW I hold a FLT licence.

 

[Specialist]

Aye but think of the money we make when they mess up.

 

[Knobhead]

I was on a salary so it just caused me aggravation
:33:

 

[Specialist]

I was on a salary so it just caused me aggravation
:33:

Ah now thats just :thumbs_down:

 

[whitebeetle]

Ok , an update on this , i have an identical door and have removed the motor from it to fit to the door with the problem. I have wired the 6 wires from the new motor exactly as the old motor was wired in the terminal box.
There are 3 contactors only in the panel , k1,k2 and k3. Looking at the 'working door' before removing the motor , when the door is selected down , only k2 comes in , when selected up k1 and k2 come in together. The motor is Electromaten SI4/8.85/165.35,00 which i now believe to be a two speed motor.The outgoing side of k3 has its three terminals all linked together. The door should operate upwards at full speed and downwards at a lower speed hence two contactors are in on the way up. Now i have simply replaced the motor onto the 6 original terminals and the motor goes downwards (close) regardless of wether i press in k1 or k2. if i press k1 and k3 (up) then the motor buzzers as if it is stalling. I cannot see what is wrong now the motor has been replaced (knowing it is a good motor).
Anyone help ?

 

[Specialist]

If you've replaced the motor with an identical motor & connected it up properly then what do you have left ?: Wiring, Contactor / Controller.
As has been said previously it's quite likely that when the motor wiring was ripped out it killed the contactor.