Voltage conversion for machinery

[Bob_McBob]

I'm not sure if it's okay to post this here since it's not a CNC-specific question, but I was doing some Googling and found some really great posts about similar stuff, and there aren't a lot of forums where everyone regularly uses and discusses high voltage power supplies, transformers, phase converters, etc.

I have a wire drawing machine from Europe that runs on 220/380v three phase, 50hz. I have access to both 120/208v and 347/600v (well, 575v in Canada, apparently), both 4P Y, and I'm not sure what the best approach is to run the machine. I've been told that running it at 60hz isn't really a big deal, but obviously I need some way to get the proper voltage from the power supply. Would a step down transformer be appropriate? What should I be looking for if buying used?

I'm also a little confused about how to wire it up, since the power cable attached to it has a ground wire that runs to the main motor as well as a secondary lubricant pump motor, and neither of the power supplies have the extra grounding pin.

I'll probably also be adding another machine that has the power requirements described as "200/400v 3 phase". Since that's not a 1/3 phase voltage split, does it mean it can run with 3 phase power at either voltage? In this case, the existing 208v supply would be ideal, correct?

Any advice would be very much appreciated

[Zig]

In general there is no problem in runing a machine ( motor or transformer ) designed to operate at 50 Hz on 60 Hz supply.

There may however be a problem in operating 60 Hz machine on 50 Hz. This is to do with the fact that 50 Hz equipment generally has more iron in its magnetic path than 60 Hz eequipment and therefore when 60 Hz equipment is operated at 50 Hz it is more likely to experience saturation of magnetic core and subsequent current wave form distortion. This would resylt in higher iron and copper losse ( that is to say higher hysteresis loses in the magnetic circuit and higher I^2R ( heating) losses in copper ( windings)).

Your 50 Hz machines will run happily on 60 Hz ( albeit a bit faster), all you need do is ensure the correct type and number of phases ( 3 phases 120 electrical degrees apart ) and correct voltage.

In fact the correct voltage could be the plate voltage of 50 Hz equipment multiplied by new frequency and divided by 50 Hz ( roughly ).

QUESTION... what do you mean by 4P Y? four phase ???

[Bob_McBob]

Sorry, I meant 4 pole, but they are 4 wire outlets, i.e. with the neutral, but no ground. I believe the plate on the motor actually says 380Δ, and it's 3kW. The pump motor runs on the same voltage. The machine is from the 70s and has been completely rewired, though.

[Al_The_Man]

Are you sure that the 4 pole are 3 phase and Neutral? And not 3 ph & ground?
It is generally against the code in N.A. anyway to not include a ground conductor.
If you are just hooking up 3 phase motors and do not need a neutral, you could disconnect the neutral conductor at the source and connect to the Ground terminal at the panel and colour tape it green at the terminations points and use it to ground the frame of the motor.
Al.

[Bob_McBob]

I could be mistaken. I'll check the meter readings tonight, but the main breaker for the room is 120/208V, 4 wire, 3 phase, supplying all the 120V single phase outlets as well. The 600V supply comes from a separate breaker I can't access.

When I've sorted this out, if I want to run the 380V machine, what is likely to be the best option? Step down from 600V, step up from 208V? I don't really want to strip the motors and replace them and all the wiring. I'm also a little concerned because we are moving rooms next year, and might only have access to the 120/208V supply in the new one.

[Al_The_Man]

Firstly I would find out if the machines are set up/wired for a certain voltage, if the voltage is set in by voltage taps in the machine panel then the machine/motors themselves could all be one voltage regardless of the input voltage.
IOW, if I have a machine that is set up for 440 throughout and I want to run it on 220 and change the motor taps to suit, then I would have to change the motor overloads and fusing to suit.
But if the input is configured to suit the supply as I mentioned in the first part then it usually should not matter.
You really need either the exact specs or an input schematic to confirm it.
Confusing I know.
Al.

[Bob_McBob]

I checked both outlets. As expected, on the first one I got 120V between each line and the fourth pin, and 208V between each pair of lines. Same situation with the higher voltage outlet (347/600).

The machine has a five wire lead installed, which includes a separate ground wire. The electrical box is rather difficult to access, but I did take a panel off the motor and confirmed it is wired up as delta (as indicated on the information plate). There is also a ground wire going to the motor which is just connected to the chassis. The pump motor is also meant to run at 380V, so it's probably safe to say that is the input voltage, but I'll obviously look into it more before proceeding.

Assuming I want to run this from either the 208V or 600V supplies described above (once I've checked everything), what is the best option?

[Zig]

If all the motors are hooked up in delta configuration...
and all the motors are rated to run on 380V delta...
then reconfigure them to run star connected....

on 600 V 60Hz directly

and make sure the switchgear and wiring are good for 600V 3 phase

fingers crossed