LowEnergyParticle
Electrical
- Feb 14, 2002
- 13
I need to select a 1/2 HP motor. The basic service is 1740 rpm, single-speed, 120/240 VAC single-phase, runs 8 hours/day, lightly loaded at 20% capacity except for intermittant 1% duty cycle 2-second long requirements for up to 80% capacity. The motor will be face-mounted into a 30:1 worm gear right-angle gearbox. The environment is room air, ambient operating temperatures 5C - 55C.
Quiet operation is an important feature: unfortunately, instead of a number I've been told "as quiet as you can make it." Oh, joy.
Additionally, the motor will be extremely difficult to access for service, so long term reliability is important with MTBF > 10,000 hours.
I was thinking perhaps a split-phase motor in a TENV enclosure, possibly with a passive convection heat sink? TEFC is tempting, but I'd like to eliminate the fan noise if possible. What made me think of the split-phase motor was reliability: no brushes, and no capacitor. It would be great to eliminate the centrifugal switch, as well: has anyone experience with a start winding that does not need to be switched out, that is, that runs continuously while the motor is powered? Obviously, it would cost some efficency, and increase the heat output.
Lastly, several manufacturers have an option where they will dynamically balance the rotors of your motors to a finer tolerance than is normally done. Has anyone any experience with doing this, and did it appreciably reduce the motor noise?
I'd appreciate your advice very much on how to keep this motor quiet and reliable. I may be quite wrong about specifying a split-phase motor, it's just an idea.
Thank you!
David
Quiet operation is an important feature: unfortunately, instead of a number I've been told "as quiet as you can make it." Oh, joy.
Additionally, the motor will be extremely difficult to access for service, so long term reliability is important with MTBF > 10,000 hours.
I was thinking perhaps a split-phase motor in a TENV enclosure, possibly with a passive convection heat sink? TEFC is tempting, but I'd like to eliminate the fan noise if possible. What made me think of the split-phase motor was reliability: no brushes, and no capacitor. It would be great to eliminate the centrifugal switch, as well: has anyone experience with a start winding that does not need to be switched out, that is, that runs continuously while the motor is powered? Obviously, it would cost some efficency, and increase the heat output.
Lastly, several manufacturers have an option where they will dynamically balance the rotors of your motors to a finer tolerance than is normally done. Has anyone any experience with doing this, and did it appreciably reduce the motor noise?
I'd appreciate your advice very much on how to keep this motor quiet and reliable. I may be quite wrong about specifying a split-phase motor, it's just an idea.
Thank you!
David