# how to connect 380v 3-Phase 50Hz Machinery to Outlet 480v 3-Phase 60Hz



## macssam (Jan 8, 2015)

hi everybody

how can I connect a European or Chinese 
Milling Machine and Lathe 
which is 380v 3-Phase 50Hz 
to a US 480v 3-Phase 60Hz outlet

I know how to connect European 220v/50Hz
to US single phase oulet

the frequency difference from 60Hz down to 50Hz can be ignored as long as there are no timers
the frequency difference might only effect the motor life time

thanks for your suggestions in advance


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## Beone (Jan 8, 2015)

A VFD is your best bet


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## poway_bob (Jan 8, 2015)

Contact a commercial electrician. I think you'll be buying a large transformer.

Bob


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## Mechanicboy (Jan 8, 2015)

Do not try self, it will cost a lot of money to repair bursted electric in tool machine. Take contact with licenced electrician to take a job for you and make your home secured against fire and full functional tool machine.


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## rik672001 (Jan 9, 2015)

You will have to change the motor and replace the power supply to the controls


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## Ken I (Jan 9, 2015)

Firstly a 380V 50Hz motor will run quite happily on 440V 60Hz - that's typically why they have such dual ratings - since the impedance is more or less a linear function of frequency 380x60÷50 = 456V no problem.

However it is going to run 20% faster (and develop 20% more power).

Your control systems are a different matter - fit a suitable transformer (or change tap settings if it has such already).

If it has a control transformer is will be either 380V (phase to phase) or 220V (phase to neutral) it may have tap setting for 440 & 260.

If it has a circuit diagram in the manual - can you post it - save all this guessing.

Like a previous post suggested get help from someone who knows what he is doing - this is not to be trifled with.

Your motor will be fine and hopefully the change should not be too costly - I used to be a plant engineer for a US firm operating in South Africa and we moved machinery back and forth from 380V 50Hz to 440V 60Hz all the time - all we had to change was the tap setting on the control transformer.

Regards,

            Ken


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## Wizard69 (Jan 9, 2015)

macssam said:


> hi everybody
> 
> how can I connect a European or Chinese
> Milling Machine and Lathe


Manual or CNC?   Modern or Vintage?

I ask because some of the old CNC controllers are sensitive to power quality. 


> which is 380v 3-Phase 50Hz
> to a US 480v 3-Phase 60Hz outlet


Any machine requiring 480 3 phase needs a properly sized feeder or bus bar drop.  


> I know how to connect European 220v/50Hz
> to US single phase oulet
> 
> the frequency difference from 60Hz down to 50Hz can be ignored as long as there are no timers


It isn't that easy, depending upon age and how much electronics are in the machine you can have line frequency problems.  The more modern the control the the fewer problems.  


> the frequency difference might only effect the motor life time
> 
> thanks for your suggestions in advance





The best suggestion I can make is to either get professional help or do an engineering review on your own.  If these are manual machines there won't be much to it.   However the more controls in the machine the bigger the potential for a gotcha.


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## Mechanicboy (Jan 9, 2015)

2 ways to choose:

1: Fix yourself and insurance does not cover fire caused by electrical fault and you lose everything you own.

2: Authorized electrician fixes for you. You get guarantees that it will work and all paperwork is in order and you get covered by insurance if it would burn down the house or failure of electrical system in machinetool or in the house.


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## gus (Jan 9, 2015)

Your power supply did not match nameplate voltage and generating frequency. Motor will burnt out very fast. Only way is rewind motor to suit power supply and hertz. Will cost a bomb.
Good Luck.


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## Ken I (Jan 9, 2015)

Sorry Gus but 380V 50Hz is freely interchangable with 440V 60Hz.

I've been doing it for years without any problems.

Sometimes the legend plate will give both.

However if you were to run a 380V 50Hz on 440V 50Hz - then (as my old lecturer used to say) hot copper will come pouring out of your motor.

Regards,

             Ken


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## SmithDoor (Jan 9, 2015)

Some will run on 240 volt 60 hz
 Note The spindle will run faster by 1.2X
 I have had motors that ran on 480 v just find for years

 Good luck  :fan:
 Dave



macssam said:


> hi everybody
> 
> how can I connect a European or Chinese
> Milling Machine and Lathe
> ...


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## macssam (Jan 9, 2015)

many thanks for all your answers
the posts of "Ken I" make perfect sense
I have been running european 220volt/50Hz since a long time without any problems

my father in law who was a motor winder for heavy duty power generating equipment
told me that timers would run faster and the life span might be reduced

newer european machinery is 400volts now
good quality phase and frequency converters are very expensive


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## Ken I (Jan 10, 2015)

Most modern timers run off an internal "clock" and are not frequency dependent.

Obviously where they are frequency dependent they are going to run 20% quicker.

Regards,
            Ken


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