Electric motor dynamic analysis
Electric motor dynamic analysis
(OP)
Has anyone ever tried to high tune a motor base? In my experience these are balanced, and also basically impossibly to high tune for the motor operating frequency. A checker is trying to get me to do the check now and I need some backup for my position though






RE: Electric motor dynamic analysis
RE: Electric motor dynamic analysis
RE: Electric motor dynamic analysis
If this is sitting on steel framing, it should be a simple matter to do a dynamic analysis. (I.e. time-history.)
RE: Electric motor dynamic analysis
RE: Electric motor dynamic analysis
RE: Electric motor dynamic analysis
I'm specifically referring to ACI 351.3R. This ACI document gives a number of criteria for calculating machine unbalance for equipment meeting standard ANSI / ISO / API criteria.
And, there are relatively simple hand calc methods where you can calculate an approximate dynamic amplification factor based on the ratio of the operating frequency of the equipment to the natural frequency of your structure.
Amplification = 1/(1-feq/fstructure)
Though your best bet is to show that the structure's natural frequencies are not within 20% of the operating frequency of the structure.
RE: Electric motor dynamic analysis
Are there going to be occupied spaces adjacent to the motor or on the floor below?
Does the motor drive an airhandler?
The potential for transmitted noise and vibration from a well balanced motor is pretty high.
Add some interesting belt frequencies, and 120 Hz electrical hysteresis and it would not surprise me if the occupants will know whenever the device is running.
Careful isolation of the motor and auxilliearies is often necessary on upper stories.
http://www.mason-industries.com/masonind/_doc/pdf/...
RE: Electric motor dynamic analysis
RE: Electric motor dynamic analysis
I have not been involved in tuning an electric motor pedestal, but 3600 rpm electric utility steam turbine / generator pedestals are routinely high-tuned. I would expect doing the same for an electric motor is possible, too.
Perhaps this paper will be of help:
http://yoga10.org/Documents/SPVKPSERCpaper.pdf
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Electric motor dynamic analysis