determining motor wiring/ operating voltage

[kd1yt]

I've got a new-to-me Cinci Toolmaster milling machine with a 3phase motor with a nameplate that says 220/440 volt. The wires within the motor head's reversing switch housing are intact but tender (brittle cloth covered wire). I will be running 220 (more like 240). How can I tell if the motor was previously set up for 220 or 440 while doing as little as possible to physically handle those many wires stuffed into that small space? I know that feeding 220 into a motor wired for 440 won't cause horrid overloads, but also recall that running motors at less than rated voltage causes them to pull more current than normal in a way that is not good for motors.

Thanks!

 

[jbroomeauto]

You should find numbers on the wires, also you should have a high/low voltage diagram on the motor somewhere. Just wire for low voltage. You could also google wiring a 3ph motor low voltage "Delta Run". Hope this helps!

 

[mzayd3]

How many wires are included with each phase conductor coming in? If only one, it is 480. If there are two wires with the phase conductors coming in, then it's 240.

 

[JimDawson]

How many wires are included with each phase conductor coming in? If only one, it is 480. If there are two wires with the phase conductors coming in, then it's 240.

To expand a bit on what mzayd3 said

Low Voltage (230V)
Connect motor leads 4-5-6 together
Connect motor leads 1-7 to L1
Connect motor leads 2-8 to L2
Connect motor leads 3-9 to L3


High Voltage (460V)
Connect motor lead 1 to L1
Connect motor lead 2 to L2
Connect motor lead 3 to L3
Connect motor leads 4-7 together
Connect motor leads 5-8 together
Connect motor leads 6-9 together

To reverse motor direction, exchange L1 and L2

 

[Alan Douglas]

Running the motor at a lower voltage shouldn't cause any problems, as long as you're not driving anything with it.

 

[kd1yt]

To expand a bit on what mzayd3 said

Low Voltage (230V)
Connect motor leads 4-5-6 together
Connect motor leads 1-7 to L1
Connect motor leads 2-8 to L2
Connect motor leads 3-9 to L3


High Voltage (460V)
Connect motor lead 1 to L1
Connect motor lead 2 to L2
Connect motor lead 3 to L3
Connect motor leads 4-7 together
Connect motor leads 5-8 together
Connect motor leads 6-9 together

To reverse motor direction, exchange L1 and L2

Thank you- I'll have to look a bit more inside the motor's wire box which is also the reversing switch mount area; it's pretty crowded in there; now, at least, I have some ideas on what to look for.

Thanks!