2007-12-17 01:21:58 · 10 answers · asked by Asha 2 in Science & Mathematics ➔ Engineering
For the same speed, single phase is hitting the motor with 60 positive pulses of power per second and 60 negative pulses in between, passing through zero in between, so any loose bits get rattled forward then back. Three phase has 3 times as many pulses per second in each direction and the impulses over lap, so there is a smoother drive.
Graph
http://users.ticnet.com/mikefirth/electric.htm#THREE-PHASE
2007-12-17 01:29:03 · answer #1 · answered by Mike1942f 7 · 2⤊ 1⤋
It can be shown mathematically that "The total instantaneous power for a balanced 3-phase system is constant and is equal to 3 times the average power per phase.” That means that the rotating stator and rotor magnetic fields in a three phase motor are not pulsating at all as they are in a single phase motor.
Edit 1
I would agree that size, fan etc. probably have more to do with the differences in sound than 1ph vs 3ph, but I suspect this is an academic question that should have been preceded by "all other things being equal."
2007-12-17 02:51:05 · answer #2 · answered by EE68PE 6 · 0⤊ 0⤋
I think you will find that for any given motor size, the type of enclosure and fan size or design has more to do with noise than any other variable.
You also have to be careful about what you think may be a noisier motor but is just a difference in frequency that one motor might generate versus another.
2007-12-17 03:14:41 · answer #3 · answered by oil field trash 7 · 1⤊ 1⤋
Single phase is a sine wave so the electricity is constantly going on and off.
The three sine waves of triple phase are evenly spaced so the electricity is virtually not going off at all thus making the operation of the motor smoother.
2007-12-17 01:28:34 · answer #4 · answered by Dennis Fargo 5 · 2⤊ 0⤋
Noise = vibration?
I don't think that your question has an answer. A big 3 phase motor is going to be much more noisy that a small single phase motor. Even for motors of the same frame size you can engineer either unit to be the quietest.
2007-12-17 01:30:19 · answer #5 · answered by frothuk 4 · 0⤊ 4⤋
I personally never noticed a difference mainly because there are many variables to consider here. Are either of these units balanced, using quiet bearings? In the Navy we would send motors out to be balanced and sound checked. The sub-Navy sends all the electric motors out to pass test for quiet operation.
2007-12-17 01:27:22 · answer #6 · answered by Ken L 3 · 0⤊ 1⤋
It should not be. Are you referring to two particuar motors? If so the noisy motor may have bad beaings or may not be balanced properly.
2007-12-17 01:32:34 · answer #7 · answered by Anonymous · 0⤊ 2⤋
The higher noise may be because of more hysteresis losses
and low starting torque.A centrifugal switch's action may add more noise.
2007-12-17 01:29:32 · answer #8 · answered by Anonymous · 0⤊ 4⤋
there are certain types but you can find them using the EndNote program or sometimes public library has them
2016-04-09 21:33:35 · answer #9 · answered by Anonymous · 0⤊ 0⤋
to this I know a little about this question
2007-12-17 01:25:11 · answer #10 · answered by Curtis c 1 · 0⤊ 5⤋