I am having an European machine installed. The book I have calls for 3 phase 400 volts at 50/60 hz.
Did you get the nameplate rating correct? 400V @ 50Hz is okay!
If the machine is a motor load, then 480V@ 60Hz won't be a problem on that motor. Keep in mind that an increase in supply frequency will increase the inductance of the motor windings: So, using a motor designed for 50Hz could still be usable using 400V X (60Hz/50Hz) = 480V @ 60Hz. The key here is V/f ratio (volts per hertz ratio). At 50 Hz, 400 volts, the V/f ratio is = 400/50 = 8 and the V/f ratio when using the same motor @480V, 60 Hz is = 480/60 = 8. Equal.
What you have to verify is the loading of the motor, careful not to overload it. The motor designed for 50Hz will run faster at 60 Hz and the motor output per design will not be enough to carry the actual load assuming the load torque is fixed and ran at a higher speed of rotation:
Code:
HP = Torque X Speed /5250
HP[SIZE="1"](60)[/SIZE] Torque[SIZE="1"]60[/SIZE] X Speed[SIZE="1"]60[/SIZE]
--------- = ------------------------
HP[SIZE="1"](50)[/SIZE] Torque[SIZE="1"]50[/SIZE] X Speed[SIZE="1"]50[/SIZE]
HP[SIZE="1"](60)[/SIZE] Speed[SIZE="1"]50[/SIZE] X 60/50
--------- = -----------------
HP[SIZE="1"](50)[/SIZE] Speed[SIZE="1"]50[/SIZE]
HP[SIZE="1"](60)[/SIZE]
--------- = 60/60 = 120%
HP[SIZE="1"](50)[/SIZE]
Clearly, the motor will draw 120% of shaft output at 60Hz for the same torque load.
But if there are other accessories of that machine of yours that really need 400V, you need to provide 400V.