3 phase motors against single phase

[shinmin]

assignment ko po. Why is it that large factories use 3 phase motors instead of single phase motors?

[motion55]

I know of two reasons.

1. You can deliver 73% more power for 50% more wire. That is, you deliver 1.73X more power by using 3 wires instead of 2.

2. Torque and power delivered by a 3 phase motor is smoother than a single phase one.

[rdpzycho]

may pasok pa kayo?

kasi 3 phase ang supply nila...

size ang unang factor, mas maliit ang 3 phase motors compare to single phase motors of same power rating...homework mo na research bakit...

second, mas madaling mag-start ang 3 phase dahil from the line meron ng phase differences needed to rotate the motor (though minor consideration to)...

third, torque ripple...imagine why car engines normally have at least 4 pistons in different phases...

fourth, transmission wiring...mas maliit wires na kailangan papunta sa 3 phase compared to same power single phase...

at marami pang iba...

[Born2BeWired]

Another compelling reason: Speed control (with vvfi)

[Ganda692002]

Another compelling reason: Speed control

ito talaga yung reason.. They also save energy by controlling the speed of the motor..

[rdpzycho]

meron ding vvvf's for single phase motors pero mas madali implement sa computations yung 3 phase (or siguro dahil mas maraming references especially on field oriented controls)...