patm72
Electrical
- Sep 2, 2004
- 42
How do motor manufacturers do to obtain a given class of insulation? I am mostly interested in knowing if a motor that I know runs very well with a 480V rated VFD (supplied with the same line voltage), can run well with 600V as the line voltage at the VFD. Obviously, the VFD would be rated for 600V in that case.
The motor is a high-speed PMSM (18krpm +) with an unknown dielectric withstand rating. It currently runs very well with a line voltage of 480V to the VFD, and we use a sine wave filter between VFD and motor, resulting in a voltage measured at the motor leads of some 300-350V, depending on the power size. Bearings are not the typical ball/roller bearings, they are air foil. Pitting is not an issue. Insulation class is H, temp rise is B.
My concern has only to do with the pulses magnitude and their possible stresses on the insulation at this point.
The manufacturer of the motor would not give me much in terms of answering my question, in case you intend to make me ask. It is as if they don't know themselves what they are doing, but it is indeed a reliable motor, and specifically adapted.
What could I ask for about their manufacturing process that might help reveal what voltage insulation they are getting?
Cheers!
The motor is a high-speed PMSM (18krpm +) with an unknown dielectric withstand rating. It currently runs very well with a line voltage of 480V to the VFD, and we use a sine wave filter between VFD and motor, resulting in a voltage measured at the motor leads of some 300-350V, depending on the power size. Bearings are not the typical ball/roller bearings, they are air foil. Pitting is not an issue. Insulation class is H, temp rise is B.
My concern has only to do with the pulses magnitude and their possible stresses on the insulation at this point.
The manufacturer of the motor would not give me much in terms of answering my question, in case you intend to make me ask. It is as if they don't know themselves what they are doing, but it is indeed a reliable motor, and specifically adapted.
What could I ask for about their manufacturing process that might help reveal what voltage insulation they are getting?
Cheers!