I am sending a machine to Brazil ( 380v 3phase  60hz).  I have a motor that is rated at 208-230/460 at 60hz and  190/380v at 50hz. Will this be alright over there or should I install a VFD. I called the manufacturer and they said it is rated for 380v at 50hz, and would not go into it any further.

Motors are designed around a ratio of volts and Hz and can typically accept a 10% variance. So a 460/60 motor has a V/Hz ratio of 7.67:1' and a 380/50 motor has 7.6:1, so it works. But if you need 380/60, that's 6.3:1, not good.

Call Weg, their motors are made in Brazil.  

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so a VFD would be in order then.

so a vfd would be in order then

You should be more specific in you question.

- power rating
- speed
- with or w/o gearbox
- application

Solving this issue with an VFD is not as foolproof as it looks like. Maybe the motor is also operated in braking mode. This would require an VFD equipped for this purpose (brake resistor or Active Frontend). Furthermore you also might need some additional equipment like line chokes, EMI-Filter and motor filter. I wouldn't use an VFD in this case unless I can get some additional benefit from this change in the system (better process control or energy saving). If this is not the case, exchange the motor to a properly rated one like suggested by  jraef .

But if the motor is used without gearbox and the number of pole-pairs is low, you might have an issue with speed:

~ 3600 rpm for 60 Hz vs 3000 rpm for 50 Hz

or

-1800 rpm for 60 Hz vs. 1500 rpm for 50 Hz

For low speed you can adapt by changing the number of pole-pairs or the gearbox ratio.

I seem to be the only one who has done this but I have done this a lot. I have also seen this done for rental equipment for 347/600 Volt job-sites which must be fed from a portable generator. There are thousands of rental generators available for 480 Volts but none for 600 Volts.
Use an open delta auto-transformer boost circuit. It take two small boost rated transformers and does not degrade the motor performance. A lot cheaper and much more foolproof than a VFD.
Investigate adding a transformer set in front of the whole machine. Then you can add a transformer set to an off the shelf machine for the Brazilian market.

Bill
--------------------
"Why not the best?"
Jimmy Carter

Thanks guys for the help.  It is just a simple application or machine. A belt driven Chamfer machine. It has a Run button, an E-stop and basically a small control transformer for the contactor overload setup and cube relay. There is no PLC or HMI or such for noise interference issues. A step down or step up transformer would probably work but the drive would actually help with speed control for differing hardness material. And a drive may be cheaper and easier to mount.

Hi deetz,

If the motor is rated 208-230/460 V -60 Hz then the L.V connection is the twice of H.V Connection. If the Motor rated connection is 2D-D and the motor has 12 leads, you can reconnect it in 2Y and will works fine at 380V-60 Hz.

In the case you have a DD-D Motor and 9 leads you could send the motor to one shop and take out the other 3 leads and reconnect in 2Y.

Regards,

Carlos