Magnetic switch wiring for 220v

[gianc]

I currently have a Rockwell Unisaw wired for 120 v. I would like to change it over to 220 voltage. I know you need to rewire the motor, but is there any change to the wiring of the magnetic switch ?

Thanks

[J.P.Rap In Hamilton]

That depends Gianc.
Im not familiar with the wireing of your present switch but for 220 you must switch both lines. For 110 you only need to switch the black line but the white line may also be switched.

Most likely yes.
If the white wire coming into the switch is conected to the white wire going to the motor (with a marr connecter or on a common screw) then the wiring and possably the switch have to be changed.

If the white wire goes into the switch mechanism before it goes to the motor, you may be ok.
To test...(you need a multi meter) unplug the saw and with the switch off check for resistance from the line-in side of the switch to the line-out side on the same wire (white or black). You should have an open circuit (no change on the meter). Check both wires.

If you have low resistance (low ohms on the meter) then the wire is not switched off and a change will be needed.

In 110 only one line is hot. In 220 both lines are hot.
Switching one line will stop the motor but the other line is still hot and this creates a dangerous situation.

Have a look at the switch. If your not sure, take a picture and post it here. We can help further if needed.
Maybe someone with the same saw can be more precice.

Good luck.
J.P.

[Gary in Niagara]

You will also have to check the voltage of the coil and either supply the right voltage or change the coil.

[edh]

I have a Rockwell Unisaw and switched it from 3 ph to 220 1 ph. I had to change to a new 3hp motor and put in a new magnetic switch. This was done by me after I recieved helpfull advice from the Delta service center here in Calgary.
I suggest you contact a nearby Delta service center.
In any event, both the motor(Baldor 3 HP,for which I was able to make a swap plus a little cash at a local electrical dealer) and the switch ( Delta, purchased at the Delta service center), came with full instructions about wiring 220. A wiring diagram is also pasted inside the electical connection box on the motor and inside the switch cover.

Hope this helps.
Ed

[J.P.Rap In Hamilton]

I missed that one.
J.P.