50 cycle machines on 60 cycles

[ohmer]

I recently looked at a machine rated 230v 3ph. 50 cycles 2.2kw made in Italy,I have 208v 3ph 60 cycle available to hook up this machine.I realize that at 60 cycles the machine will run a bit faster but I was wondering if it is advisable to boost the voltage or not ?what are long term effects on the machine if any?
Thank you

 

[ohmhead]

Well id say the lower voltage might be better if you have to use it .

Its all about magnetic field at a high voltage it will be over staturated and at a higher speed of 60 hz can effect your motor windings but there are others on line to give you a better reason then me trying to explain this .

 

[gar]

100213-1728 EST

You need to define the machine more. Is it mostly induction motors driven from the AC line, no VFD, etc.? Is there electronics? What does the machine do?

Generally a 50 Hz machine can be run at a higher voltage on 60 Hz because you are lower on the saturation curve when at the same voltage but at a higher frequency. This results from the volt-time integral and its relationship to magnetic flux density. Lamination thickness is a separate problem relative to frequency.

.

 

[Besoeker]

I recently looked at a machine rated 230v 3ph. 50 cycles 2.2kw made in Italy,I have 208v 3ph 60 cycle available to hook up this machine.I realize that at 60 cycles the machine will run a bit faster but I was wondering if it is advisable to boost the voltage or not ?what are long term effects on the machine if any?
Thank you

With higher frequency and the same voltage you get more speed and less torque. With lower voltage you will also get less torque (roughly as the square of the voltage.
So a double whammy on torque.
In round figures, if you supply the 2.2kW 230V 50Hz motor with 208V 60Hz you will get less than half rated torque.
If what you intend to drive only needs that and if it can cope with the extra speed, you should be fine.

 

[ohmer]

Well thanks for the replies everyone this gives me something to go on.For further clarification about the machine it is a condor 90 cnc-fe hr which is a cnc high speed cutoff machine for non ferrous metals like brass and aluminum ,it cuts with a round saw blade and only has 1 motor and no vfd that I can see.The owner has run it at 240v that was bucked down from 480v and told me it ran fine but he has moved the machine into a new area that 208v is readily available and 480 is not.So I think we will give it a try and see what happens,if it needs more power I can boost it with transformers but there doesn't seem to be an economical way to change hertz.I suppose worse case scenario would be to change motors.

 

[sberger3]

I realize that at 60 cycles the machine will run a bit faster but I was wondering if it is advisable to boost the voltage or not ?

No, it is not necessary to boost the voltage for the machine : it will work fine (actually better on 60 hz than it did on 50hz). THE COILS ON RELAYS/CONTACTORS (IF ANY) WILL NOT WORK PROPERLY: CHANGE THEM OUT).The reason the machine will be okay is:a 50 hz machine of the same horse power will contain more copper than the came machine designed for 60hz.The higher copper content will more than compensate for the lower voltage.One big advantage: you will experience a 10% gain in the horse power rating of the machine on 60hz.(the opposite is also true putting a 60hz on 50hz).

More common is the 380V 50hz machine. A few years back, a motor shop in my area worked with me to install a German manufacured production line.(380v 50hz). We installed the 380v 50hz machine on 480v 60hz and experienced a 10% horse power gain over the name plate and no long term effects on the machine. When I am buying used on E-Bay etc. I usually buy 50 hz because they are almost always cheaper and more durable(horse power rating comparison).

what are long term effects on the machine if any?
You will experience a 10% horse power gain, but no ill effects from the lower voltage. WARNING: IF THERE ANY COILS ON RELAYS/CONTACTORS ETC., THEY MUST BE CHANGED OUT.

Good luck,


Thank you[/QUOTE]

 

[Besoeker]

No, it is not necessary to boost the voltage for the machine : it will work fine (actually better on 60 hz than it did on 50hz).

That would depend on your definition of better. If you give it nameplate voltage and 60Hz instead of 50 Hz, it will run faster but produce less torque at rated current.

The reason the machine will be okay is:a 50 hz machine of the same horse power will contain more copper than the came machine designed for 60hz.The higher copper content will more than compensate for the lower voltage.

I'm afraid that's just wrong. At reduced voltage you will get reduced torque.
It goes down approximately with the square of the voltage.

In this particular case, the frequency is increased and the voltage decreased.
Each results in reduced torque and in combination, very much reduced torque - to less than half as I previously noted in post #4.