Single Phase Motor Wiring

[Carl SwainParticipant @carlswain69523]

Does anyone have experience of Crompton Greaves Single Phase motors?

I trying to wire a motor (image attached) through a drum switch, but I'm struggling to find enough information to wire the main and starting windings separately.

[Carl SwainParticipant @carlswain69523]

[EmgeeParticipant @emgee]

Is it a Dewhurst fwd/rev switch ?

If it's not a Dewhurst do you have details of the switch terminals/connections ?

Emgee

[Carl SwainParticipant @carlswain69523]

It's a 'Santon' drum switch as below.

Power to terminals 2 & 6

Starter Winding to Terminals 1 & 4

Run Winding to Terminals 2 & 5, with a link between Terminals 3 & 5

I've done some further testing, and I'm closer to being able to solve the problem.

Red and Black are the Main Winding

Blue and Yellow are the Starter Winding

Purple & Red/Black are the Centrifugal Switch.

What confused me was the Run Capacitor not being in the circuit.

[Les Jones 1Participant @lesjones1]

Hi Carl,
I suspect that terminals K and AZ are linked internaly. Can you measure the resistance between them to see if this theory is right or wrong ?

Les.

[john fletcher 1Participant @johnfletcher1]

The run capacitor is connected in series with the start winding all the time, initially its connected in parallel with the start capacitor (the high value one) via the CLOSED centrifugal switch. When the motor is up to about 75% of its maximum speed the switch opens, leaving just the run capacitor in operation. By the way, these forward and reverse switches are not man enough to be used as an ON/OFF switch they soon burn out the contacts. You ought to use a proper motor starter with Green/Red Button with No Volt release to turn the motor on after selecting the direction of rotation. So, select. direction of rotation then press the green button. John

[Carl SwainParticipant @carlswain69523]

Les,

Just tested that this morning, and K doesn't appear to be connected to anything. It looks like the motor has been configured as Capacitor Start, Induction Run, but I'll check with the supplier on Monday.

[Les Jones 1Participant @lesjones1]

Carl,
Does the motor have one or two capacitors ? I am wondering if it does not have a run capacitor. If we can understand the motors internal wireing we would probably only need 4 wires (PLUS AN EARTH) between the switch and motor. Without understanding the internal wiring we could connect it like this.

This would require 5 wires (PLUS AN EARTH)

Also I agree with John's comment that the reversing switch should not be operated  as a power switch. It should be fed via an NVR switch.

Les.

Edited By Les Jones 1 on 24/01/2016 10:01:04

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