Foreign Italian Motor Voltage In Domestic Application

[huskernation480]

I just accepted a position as plant electrician at a very fast growing local manufacturer. They just received press machines shipped in from Italy that were ordered clear back in March. Needless to say, they want them up and running yesterday.

The motors on said machines are marked at 220/380 vac 60 hz 3 phase. There is no proper documentation included with the machines, and what is provided is in Italian. The ladders are decipherable, obviously, but I have concerns.

First, I have much experience with German machines at this European voltage, which were always 50hz. They came shipped with freqs and transformers for U.S. installation at the high side. (480 down to 380-400). I guess I will just ASSume these motors are stamped correctly.

My main concern is that in this part of the building, I only have 208, 3 phase wye available. There is no variance marked for these motors. Should I be concerned about 6%?

 

[Jraef]

In a nutshell, maybe. IEC motors have no "Service Factor" like ours do, they cannot tolerate very much of a drop in design voltage. But if that nameplate is true, then by virtue of the fact that it says 220V, not 230V, then it might be OK.

but...

The motors on said machines are marked at 220/380 vac 60 hz 3 phase

Doesn't sound right.

You must supply the motor with the correct ratio of voltage AND frequency. 400V 50Hz is a V/Hz ratio of 8:1 (400/50). 480V 60 Hz is ALSO a V/Hz ratio of 8:1, so you can usually supply 480V 60Hz to a motor designed for 400V 50Hz and be fine, but the motor will spin 20% faster. That speed difference can be bothersome though, ie cutting tool speeds are too high for the bits/saws, conveyors run too fast, etc. etc. On centrifugal pumps is can be a killer though. But if the motor is designed as 230V 50Hz, then the ratio is 4.6:1 and if you feed it 208V 60Hz, the ratio is 3.47:1, way too different. The motor will saturate and eventually burn up.

If you truly have motors designed for 220/380V 60Kz, that's a real oddball combo. A quick search of my info on world voltages however says that Brazil uses 380V 60Hz, so maybe they bought some Brazilian motors for you. If so, you might be OK. You won't get full torque out of them at 208V, but often times designers put a little fudge into the motor selection. I would try it and monitor the motor current under operating load for a while. As long as you don't go over the nameplate FLC you should be fine.

 

[huskernation480]

Thanks for the reply. You echoed most of my own thoughts and what I was able to find online, and by comparing notes with other friends in the field and engineering. Thanks for taking the time to reply.

 

[StarCat]

European Gear

European Gear

I have an Italian machine in the plant, and in similar fashion this kind of thing is bought without real electrical consideration and you the Electrician are charged to make it work or tell the buyers that it cannot go. This unit had 3 motors by 3 different makers all having 4 different voltage figures on the nameplate for correpsonding Delta or wye configuration. Control transformer was dual voltage. I gave it a chance to work.
The single thing that was a challenge was one of the motors was running a pump. The jump from 50 to 60 hz. makes a significant RPM difference which was not foreseen.
Having the stator rewound for 208V was not very helpful. It was decided that a VFD might do the trick as we did not need full RPM on this application for the pump. After startup, one cryptic setting the the drive menu called " Flux Optimization " made the job run perfect. This was an ABB drive.
We have 4 different Italian machines on property. They are strange. Some things are more rugged, some seemingly not.