Higher Rated Voltage Motor With Low Voltage VFD

It will work but the motors output power will be roughly 75% or less of it normal ratings.

You may get the somewhat better output but at lower frequency settings,For example VFD may see that motor as 380Volts/40Hz rating.

I'm afraid it's a case of a transformer or a new motor. The new motor is the cheaper option.

If you want to do the SAME WORK with the motor, then the answer is no.

If it's OK to do LESS WORK (less kW) with the motor which means work at a LOWER SPEED then the answer is yes, as long as the lesser amount equals the voltage delta. So in your case, 380V / 500V = 0.76 x 50Hz = 38Hz. So if you program the VFD to tell it that you want the maximum speed to be 38Hz and the voltage at that speed to be 380V, it will work at that speed. But to do so, you would need to "fool" the VFD into thinking it is rated for a higher input voltage (500V) to that it puts out the correct V/Hz ratio to the motor.

Which brings up another point altogether. Where did you find a 500V rated AC motor (and why do you have one)? Never heard of it. Is it perhaps a 460V 60Hz rated motor? If so, different problem. A 460V 60Hz rated motor has essentially the same V/Hz ratio as a 380V 50Hz motor (do your own math). So if that is the case, then you have nothing to change in the motor, but it will run 20% slower and put out 20% less kW.

Check the connections. If it's star connected, change it to delta. That will sort out the volatge. Remember the current per phase will be multiplied by root 3.

Otherwise, set the VFD V/Hz to give 380V at rated motor frequency, and expect reduced torque above that.

Not irresponsible. Since when does one use a DC motor on a normal VFD?

My guess is, it's a 460/480V 60Hz motor. So, use it on 380V and remember the constant torque function up to 380V and constant power function above that!

Star/Delta connections are very often an option on industrial AC motors.

Hmmm... DC motor. That is a common voltage for DC motors, but he's right, "VFD" would not apply.

Most 460V NEMA design motors are not designed to be connected in delta as a different voltage, in fact in many cases they ARE in delta to begin with. That's an IEC motor design issue and sometimes even then it's not always the case for motors not designed for use in the UK (or NZ). Depending on the design, you can connect some types of NEMA motors in wye for reduced torque but you cannot run them that way.

By the way, I take back what I said about there being no such thing as a 500VAC motor. The Dutch (Dutchi Motors BV) make them, apparently 500V 50Hz is used in some South African diamond mines (which makes sense that a Dutch company would supply them). So if that's what you have Signode, then you will have to do the trick I said and live with the reduced power output.

You may want to consider using an auto transformer to step up the input voltage. That is not expensive.

All the other comments about reduced voltage, speed, and power are correct. You will develop rated torque at approximately NP amps.

Depending on your power supply you may even want to use a "drive isolation transformer" to step up your voltage to a VFD rated for the motor voltage. This has the advantage of helping keep some of the drive noise away from the rest of the system.

Yes. you use a "Step-up" transformer.

I do it all the time using a VSD 480v output to a downhole motor NPv of 2300V @60Hz.

I strongly suggest that as you want to use a VSD, you look at the harmonics and have the power analysed, then think about Harmonic mitigation.

Other than that it will work fine

Thanks all for replying.

We have another machine rated 500V and powered via a separate transformer, that motor is for that machine which i want to use it another machine.

I have understood now what should I do.

Ebay for the existing motor. Rather than wasting time install the proper sized motor. Your direct question was is it possible? Yes it is. But if you're working with power at this level stay consistent and just do it right the first time. Your problem will be solved, you wont be wasting time setting and adjusting it again. And, the next guy wont make a mistake thinking (assuming) he's working with one set of data or voltage when in fact it's 2 sets. That's how people get injured. You seem to be trying to save a few dollars, which is great. You would be well served to also consider safety and the next person(s) that will work with this system. Stay consistent, stay alive.