Motor wiring Monarch C lathe - Question anyone

I have just acquired a Monarch C lathe 1943, a rather nice machine - but cannot see what voltage it has been configured too in order to power it up to test it. Plates and tags are occluded. There is a small tag but I can only make out the numbers 220 240 so it does look like two choices. The motor,when viewed at the back of the lathe, has 3 wires coming out of it. They are all black. No 4th wire. There are no leg numbers on them. I cannot see a usual terminal block with Legs 1-3 and then a set of jumper terminals for the voltage setting. Two of the wires go off to the on/off box at the front of the lathe which looks original. The 3rd goes into the conduit so it looks like one leg bypasses switching or maybe it went to a disconnect but them when you switched on would this mean one phase winding would be hot before switching the lathe on at the front control. I am puzzled.

Anyone able to tell me anything about this?
Am I looking in the wrong place for the legs and terminal block?
Anyone have a wiring diagram?

Thanks,

Dave

Normal place to look for motor wiring is in the terminal box ON THE MOTOR - often referred to as the "PECKER HEAD" - this is where the NINE (or other number) "T" leads will have permanent identifying tags - mostly hiding under electrical tape,

A sure indication of a nine wire motor being CONNECTED for LOW (220ish, not 440ish) voltage operation will be TWO "T" wires for each of the three incoming or "L" wires from the power source

Unfortunately on that lathe this will likely require removing motor from the pedestal it is mounted in

Old controls like disconnects and magnetic starters concerned them selves with just two of the three hot wires - at least as to thermal overloads - a sure indication of them being way out of date

On edit - other places to look. If equipped with magnetic starter - thumbnail is an example - and you can read voltage on the coil that operates it that will be an indicator. In my thumbnail example the coil is bottom center. If for example the coil is 440V, highly likely the motor is connected for that. Having motor with one voltage and the coil with another voltage requires a CONTROL TRANSFORMER

It will not be unusual for such a lathe to be equipped with a REVERSING STARTER - two mag starters working together - each with a coil

Prototypo said:

I have just acquired a Monarch C lathe 1943, a rather nice machine - but cannot see what voltage it has been configured too in order to power it up to test it.

Click to expand...

Unless it came out of Canada, with but three wires active, it should be either 220 or 440 and "Delta" connection as far as what you need to work with.

If wired for 440, testing it BRIEFLY on 240 won't harm it, but can quckly show you if it wants 440. Motor won't come up to full speed cleanly, quickly, or even at all, and/or will bog down very obviously under even a light load if it were to do.

As to re-termiations IF even NEEDED?

You may be able to get hands and tools into the Peckerhead area without removing the motor, even if not also head and eyes.

Two things, there.

A) First, grab any available "camera phone" or even the cheapest of digital cameras or "web cams" and a "selfie" stick or equivalent. Take photos. "Blind" if need be. See what you may need to plan for.

B) IF/AS/WHEN you need to cut wires, FIRST - and ALWAYS, if at all possible - clear up the present terminations WITHOUT cutting on the wires coming into the peckerhead up out of the motor.

Usual practice of the day was to swedge a thin tin-plated band with a letter or number around each wire.

If that "ID bracelet" is cut off, THEN you'll have an extra layer of detective work to do with a meter to re-establish what is what. Not a disaster, even so. Just an avoidable nuisance.

More when we know more.

Thanks very much. This helped.

Yes it is a delta configuration and I realized the Peckerhead is inside the motor. I did find the coolant pump rated at 220 and on one leg. So for my first test I powered up with 208 3P (which was available) and it came up to speed fairly rapidly and pulled 8.5 amps average on each leg. I couldn't put it under load as the next problem was uncovered which was no engagement with the control lever and some rattles in certain speed selections. Project no 2 is in progress!