- #1
lottis
- 3
- 0
Hi guys
I have been testing a brand new 250kw 3 motor wired in delta. I have it connected to a 170 amp vfd with no load for testing. It draws 105 amps at 50hz and is balanced.
Intermittently the motor makes a strange that i have not heard before. It sounds like a spoon taping another spoon, a metal on metal sound tapping at no more than 1 hz off and on. When power is removed and the motor free spins to a stop the sound is gone. I have tried different carrier frequency but it does not make any difference.
Sometimes while making the noise the vfd trips on over current but not on output short circuit. The drive does not show a raise in current before tripping.
The motor has been check for mechanical issues, bearing/loose parts etc and none have been found.
I have tried the motor on another drive (250 amp) and it does not make the noise. I have tried other motors (55kw and smaller) on the vfd and they do not make the noise.
Thanks
I have been testing a brand new 250kw 3 motor wired in delta. I have it connected to a 170 amp vfd with no load for testing. It draws 105 amps at 50hz and is balanced.
Intermittently the motor makes a strange that i have not heard before. It sounds like a spoon taping another spoon, a metal on metal sound tapping at no more than 1 hz off and on. When power is removed and the motor free spins to a stop the sound is gone. I have tried different carrier frequency but it does not make any difference.
Sometimes while making the noise the vfd trips on over current but not on output short circuit. The drive does not show a raise in current before tripping.
The motor has been check for mechanical issues, bearing/loose parts etc and none have been found.
I have tried the motor on another drive (250 amp) and it does not make the noise. I have tried other motors (55kw and smaller) on the vfd and they do not make the noise.
Thanks