Drum Switch

[akahrim]

Hello All,

I was working on a friends lathe and I removed the drum switch from its location. In the process of wiring the the system back together, the drum switch fell apart. The lathe has a wiring diagram (I attached it to this thread). I am trying to follow it but I'm not sure what terminals on the drum switch make contact when the switch is in Forward and which terminals should make contact when the switch is in Reverse. I usually don't work with AC so the nomenclature of V, W, and U are foreign to me. Could anyone help me to understand which terminals are connected to which for the following motor operations Forward, Reverse, and Stop please? The motor is a single phase, dual capacitor starting motor. Any help would be greatly appreciated.

 

[ronsimpson]

Can you picture the switch and motor?
I think there are numbers on the switch. 1-12
There are wires on the motor. U1,U1-2,V1,W1-2.
Probably the motor and switch are not near each other. I often use colored tape or some how mark wires. The purple wire at the motor is "V1" so this purple wire at the switch is also V1.

 

[akahrim]

Can you picture the switch and motor?
I think there are numbers on the switch. 1-12
There are wires on the motor. U1,U1-2,V1,W1-2.
Probably the motor and switch are not near each other. I often use colored tape or some how mark wires. The purple wire at the motor is "V1" so this purple wire at the switch is also V1.

Hello Ron,

I have the following images from the motor and switch. You are correct when you said there are numbers on the switch. The other 6 numbers are on the other side of the switch.

 

[dr pepper]

I can tell you what happens in the circuit if thats any use.

U1 and U2 are the run windings.
V1 and W2 are the supply to the start windings via the centrifugal switch for the start/run capacitors.

The main switch applies mains supply to U1 and U2, the polarity doesnt change for forward and reverse.

The main switch applies power to V1 and W2, however the polarity will be one way forward and the other way for reverse.

 

[akahrim]

I can tell you what happens in the circuit if thats any use.

U1 and U2 are the run windings.
V1 and W2 are the supply to the start windings via the centrifugal switch for the start/run capacitors.

The main switch applies mains supply to U1 and U2, the polarity doesnt change for forward and reverse.

The main switch applies power to V1 and W2, however the polarity will be one way forward and the other way for reverse.

Hello Dr. Pepper,

Thank you for your response. It is very helpful. I working on translating this into a wiring diagram that I can post. I am just getting thrown off by the nomenclature. Are there three windings in this motor (U1-U2, V1-V2, W1-W2)? All the literature I find on single phase run start capacitor motors indicate that there are only two windings. A main winding and an auxiliary winding.

 

[akahrim]

Hello Dr. Pepper,

I have attached a PDF of what I believe you are saying. Does this look correct?

 

[dr pepper]

Yep thats it, not sure about which way around V1 and W2 are but thats not that important.

 

[akahrim]

Yep thats it, not sure about which way around V1 and W2 are but thats not that important.

Thanks alot for your help.