Magnetic Motor Starter

Something is missing from your post, you cannot start a motor with a motor. I think you meant to say "motor starter" on one of them but I can't tell which one.

Motor starters are rated by current, most of the time the voltage is always up to 600V and they work on anything lower than that.

The coil in the contactor that makes it work has a voltage rating, it can be anything that you are using for controls, i.e. 24VDC, 120VAC, it's not directly related to the motor voltage, although that's not out of the question either (just a bad idea).

If your motor HP is the same and you have a 460V motor starter now, the 208V motor will need a MUCH bigger motor starter because the current will be more than 2X that of an equivalent 460V motor. If you have a starter for the 208V motor and you want to start a 460V motor of the same HP, no problem because the 460V motor will take less than 1/2 the current. If the two motors are not the same, you start from scratch.

A magnetic starter is an electromagnetically worked switch which gives a protected technique to beginning an electric motor with a vast load. Magnetic starters likewise give under-voltage and over-burden insurance and an Automatic cutoff in case of a power failure.

As Jraef says, your post is confusing...

You have a 460V motor which you want to use on a 208V supply?

Or you have a motor to which you want to apply 208V at start, then change to 460V ?

Please explain a little more ....

you are right my post is confusing...

" I have a 460V 3ph supply I need to start a 208V 3ph motor can I use a magnetic starter? If yes, which one ? "

Thanks

Your 208V motor cannot be connected to 480V regardless of the motor starter you use. What you need is a TRANSFORMER and a motor starter to step you voltage down to 208V.

Better yet, hire an electrician to do it for you safely and legally. He will know how to deal with it.

ok

thanks for all