Condenser Fan Speeds

[John Hamblin]

I am new to AC and there are usually two speeds mentioned when referring to the condenser fan - 825 and 1075 RPM. Is the fan speed related to the size of the unit-where a 825 would be on a 2 T and a 1075 on a 4 or 5 T. If not size, what determines the speed? Thank you.

[RegUS_PatOff]

, what determines the speed?

the Engineer, and the Fan Blade size, number of Blades, pitch, etc ..

[ACtechGUY]

It has been my experience that you find low rpm motors with larger fan blades on higher end condensers. This results in a quieter unit. Tonage has no bearing on rpm selection.

[applianceman18007260692]

An 825 motor has more copper in it, is generally built to last a whole lot longer, costs a lot more, is quieter than than a 1075, and it would be a huge mistake to mount a 1075 in the place of an 825. The unit would not cool right.

[Bobice]

A fan blade designed for a 825 rpm motor will usally have more pitch than a fan blade for a 1075 rpm motor.

Basically the motor pushes more air but slower with the 825 rpm motor.

If you try to use a 1075 motor and push that fan blade with more pitch it will overheat unless you were to really oversize the motor (1/4 to 1/3 not enought).

The bottom line is you need to have the RPM's of the new motor the same as the original motor.

825 RPM motors cost about twice as much as 1075 RPM motors.

Make sure to install the fan blade properly. If it is too far away from the motor it will generate more resistance, which will overload the motor even more.

Now with the 825rpm motor, the condenser should feel warm instead of burning hot