oversizing condenser fan motors?

[delta T]

1/4 horse 1075 condenser fan motor replaced by a 1/2 condenser fan motor, does this pose a problem by spinning faster due to pitch of fan? i would like to think that this could cause over condensing problems. am i correct or am i wrong?

[mad fridgie]

Why does the fan spin faster! (excluding slippage) HP is not related to speed.

[B G Scott]

1/4 horse 1075 condenser fan motor replaced by a 1/2 condenser fan motor, does this pose a problem by spinning faster due to pitch of fan? i would like to think that this could cause over condensing problems. am i correct or am i wrong?

Speed in AC motors is related to the number of poles in the motor.

2 pole motor at 50HZ has nominal speed of 2800 RPM

4 pole motor at 50HZ has nominal speed of 1400 RPM

6 pole motor at 50HZ has nominal speed of 900 RPM.

These nominal speeds are a little less than the Synchronous speed due to slip.
It is worth mentioning that most small condenser fan motors on packaged units are Shaded Pole

[Sandro Baptista]

1/4 horse 1075 condenser fan motor replaced by a 1/2 condenser fan motor, does this pose a problem by spinning faster due to pitch of fan? i would like to think that this could cause over condensing problems. am i correct or am i wrong?



No problem. The new motor will have less load than the nominal so less thermal load on it. Will probably have more "time of life" :)

[abet_meneses]

high power consumption using a 1/2 hp motors,a costly replacement.why not replace the original.

[Sandro Baptista]

Maybe they don't have in stock for fast delivery. The higher consumption should not be very high because the fan is the same so the shaft power absorbed should be nearly the same...and maybe this bigger motor maybe have a higher efficiency, even at part load.