Help with AC motor wiring?

LesJones

Joined Jan 8, 2017
4,511
Even for home use electrical work should done properly.
I DO NOT CONSIDER THE DIAGRAM BELOW TO BE SAFE.
310323_001.jpgConnect it up as in the diagram. Tape up wire Z2 in the motor so it can't short to anything.
DON'T FORGET TO CONNECT MAINS EARTH TO THE MOTOR CASING.
Start with the switch fuse off and all three circuit breakes set off.
We will call CB1 up and CB2 down. (It may well be the other way round.)
Set CB1 or CB2 to on depending on the required direction. (CB1 and CB2 MUST NEVER BOTH BE ON TOGETHER AS THIS WILL SHORT LIVE TO NEUTRAL )
Set CB3 on. (This is performing the functon of the centrifugal switch.)
Set the switch fuse to on.
If the motor does not start within about one second switch off again at the switch fuse.
If the motor does start switch off CB3 after about a second.
To stop switch off at the switch fuse and then switch off all 3 circuit breakers.
NOTE, the switch fuse and circuit breakers were never designed to be use like on/off switches. They are designed to isolate parts of a circuit and would only be used ocasionally.

Again I would advise you to wire it up properly with interlocking contactors with thermal overloads and safety limit switches and repair the centrafugal switch or replace the motor.

Les
 
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MaxHeadRoom

Joined Jul 18, 2013
30,684
I would agree that any equipment that can be latched in to run, especially such as automotive purposes, should have a industrial style E-Stop(s) where needed for easy access .
Also, as stated, the norm is to use both electrically and mechanically interlocked contactors.
 
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Thread Starter

elioti

Joined Mar 5, 2023
50
Even for home use electrical work should done properly.
I DO NOT CONSIDER THE DIAGRAM BELOW TO BE SAFE.
View attachment 291146Connect it up as in the diagram. Tape up wire Z2 in the motor so it can't short to anything.
DON'T FORGET TO CONNECT MAINS EARTH TO THE MOTOR CASING.
Start with the switch fuse off and all three circuit breakes set off.
We will call CB1 up and CB2 down. (It may well be the other way round.)
Set CB1 or CB2 to on depending on the required direction. (CB1 and CB2 MUST NEVER BOTH BE ON TOGETHER AS THIS WILL SHORT LIVE TO NEUTRAL )
Set CB3 on. (This is performing the functon of the centrifugal switch.)
Set the switch fuse to on.
If the motor does not start within about one second switch off again at the switch fuse.
If the motor does start switch off CB3 after about a second.
To stop switch off at the switch fuse and then switch off all 3 circuit breakers.
NOTE, the switch fuse and circuit breakers were never designed to be use like on/off switches. They are designed to isolate parts of a circuit and would only be used ocasionally.

Again I would advise you to wire it up properly with interlocking contactors with thermal overloads and safety limit switches and repair the centrafugal switch or replace the motor.

Les
Hi Les, I've only just wired up as you said, it's working:) thank you so much. I've included a diagram of the switches as are currently positioned on the wall. Could I not leave cb3 always on, turn cb1 upside down so to operate I'd only have to put the first two switches up, for up, then down for down? Then the main power supply to operate. So basically is there a reason I can't leave cb3 in the up position always please? In other words if there's no main power supply, there's no reason to turn cb3 off at all? Thanks again:)
 

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LesJones

Joined Jan 8, 2017
4,511
CB3 serves the function of the faulty centrifugal switch in the motor. it should be switched OFF after the motor starts. (About 2 seconds.) If the motor failes to start or stops when CB3 is set to the off position then switch off the power at the switched fuse box.

Les.
 

Thread Starter

elioti

Joined Mar 5, 2023
50
CB3 serves the function of the faulty centrifugal switch in the motor. it should be switched OFF after the motor starts. (About 2 seconds.) If the motor failes to start or stops when CB3 is set to the off position then switch off the power at the switched fuse box.

Les.
Thanks Les, I'm at last managing to fix my car thanks to your help, much appreciated:)
 

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