Identify windings

[Bsmith]

240v single phase motor with mixed up connections and no id tags in connection box
I am quite sure the 2 wires for the centri switch will have a high resistance showing on the multimeter so they are ok.
What about the start and run windings please? Will the start or run winding have the higher resistance?

 

[carbon]

I am quite sure the 2 wires for the centri switch will have a high resistance showing on the multimeter so they are ok.

A centrifugal switch will have very little resistance

 

[Hotstuff]

If you post some photos, it might help to identify the issues with your wiring.

Good luck.

 

[Guineafowl]

Yes, pics needed. Start winding will be higher resistance. Centrifugal switch will be in series with the start winding and closed (low resistance) with the rotor at rest.

 

[Bsmith]

 

[Bsmith]

If the wiring is ok in the connector block, can you tell me which terminals to connect the live and neutral to plz?

 

[Pete.]

No connection diagram inside the lid?

 

[carbon]

Whats the value on the second capacitor?

 

[Bsmith]

No connection diagram inside the lid?

Just shows how to change links to reverse motor direction, which would be unsuitable with that connector block. Think that connection block may have been used in conjunction with a revers switch.

Whats the value on the second capacitor?

Will get that details soon.

My idea is to remove that terminal block, fit a domino block and wire it as photo (excuse rough sketch)

 

[Bsmith]

Whats the value on the second capacitor?

250v 150uF

 

[6ply]

Just shows how to change links to reverse motor direction, which would be unsuitable with that connector block. Think that connection block may have been used in conjunction with a revers switch.

Will get that details soon.

My idea is to remove that terminal block, fit a domino block and wire it as photo (excuse rough sketch)View attachment 409584

 

[6ply]

Identifying the start/run windings can sometimes be done with a multimeter. Measure the resistance of each winding (disconnected) and then report back.

 

[Bsmith]

Tried to test windings with a multimeter but when I took the connections out of the block I found that some had been twisted and soldered together. Maybe they are connected as they should be.
Should I seperate the ends of the wires and start again?

 

[Pete.]

That motor has been wired up for being reversible.

If you don't need to reverse it cut all of the connections, identify the two windings and connect it as per 6ply's diagram. If it turns the wrong way reverse the start winding wires.

 

[Bsmith]

Have I wired it wrong or is the motor knackered?

Spins up on start windings then slows, spins up again etc. Like the run windings are not doing anything.
Wires coming out of motor are,
Red - run windings
Yellow - start windings
Black - centrifugal switch
The run windings show no resistance on multimeter.

 

[Pete.]

If the run winding is open circuit then yes the motor is knackered. However, if there is a fault it's quite likely to be where the red wire joins the winding so potentially you could find the break on the surface.

 

[6ply]

If the run winding is open circuit then yes the motor is knackered. However, if there is a fault it's quite likely to be where the red wire joins the winding so potentially you could find the break on the surface.

Pete, he said the run windings "show no resistance" by which he might have meant an extremely low resistance rather than an open circuit and and therefore an extremely high resistance. Maybe @Bsmith could confirm the actual meter reading first?

@Bsmith be careful with those capacitors unless you are absolutely certain they hold no charge. They can be lethal.

 

[6ply]

Have I wired it wrong or is the motor knackered?

Spins up on start windings then slows, spins up again etc. Like the run windings are not doing anything.
Wires coming out of motor are,
Red - run windings
Yellow - start windings
Black - centrifugal switch
The run windings show no resistance on multimeter.


View attachment 410026

When testing the resistance of the start and run windings, did you make sure they were fully disconnected from any other part of the circuit?
If the resistance appears to be very high (possibly open-circuit) select the highest resistance range on your multimeter. If it still indicates 0L or similar - "over limit" - then it is likely open-circuit. In other words, there is a break somewhere.
A typical motor winding will have a resistance of just a few Ohms. This is the DC resistance which is not the same as the reactance to AC.
Any winding with an extremely low DC resistance (or "zero" resistance) will have a short circuit.

Stay safe.

 

[Pete.]

Pete, he said the run windings "show no resistance" by which he might have meant an extremely low resistance rather than an open circuit and and therefore an extremely high resistance. Maybe @Bsmith could confirm the actual meter reading first?

@Bsmith be careful with those capacitors unless you are absolutely certain they hold no charge. They can be lethal.

I know but in the pic above the red winding is showing 2.6ohms so I figured that 'no resistance" meant no reading.

 

[6ply]

I know but in the pic above the red winding is showing 2.6ohms so I figured that 'no resistance" meant no reading.

Ok, so "no resistance" and "no reading" means a reading of 2.6 Ohms resistance.

I missed the photo - thanks.