View Full Version : Need help to find the correct size condenser Fan motor

18-05-2012, 02:20 PM

I am a newbie here, appologize if I am posting in the wrong place.

I have a 3 Ton AC/Heat pump unit, manufactured by Heil, the condenser fan motor is making noise, and probably will die soon. All the markings on the motor as well as the condenser enclosure have faded/gone. The unit is 9 years old. The Air Handler in the garage is the NFCP3600C2 model from International Comfort Products Corporation.

Can some please help me find the right size motor? RPM, Horse power ?

What would slightly higher horse power do to the system? I was reading some where online that if the fan is over sized, it would lower the differential temp. of the outlet-inlet air.

Thank you for your help.

18-05-2012, 04:22 PM
Sorry I don’t know these brands but I can tell you this:

If the fan is still working you can measure the rpms now before it fails.

If you don’t have an instrument to do this, you probably have these new fancy cellphones and find a (noise) Spectrum Analyzer program. Measure the peak frequency (the one with the highest dB), divide this frequency by the number of blades and you have the frequency of your shaft and may convert to RPM.

With the number of blades, angle of attack, diameter, go to your nearest fan manufacturer website and find the shaft power that fan needs.
For example: http://www.laufan.com/catalog.shtml

You will also need information on direction of rotation and how to fix the motor to the structure, the rest you do with your wholesaler.

monkey spanners
18-05-2012, 06:25 PM
Hi AhossAC,

Phone Heil and ask to speak to their technical department, when you call have as much info as you can, dimensions of unit, pipe sizes, compressor model, etc etc, you can't have too much info. They should be able to work out what model you have and what fan motor it has fitted. It may be worth taking some picture too incase they want you to email them!


(I have had to do this with another make of equipment, got the compressor model worked out just from its physical size, refrigerant type and capacitor/relay model no.'s by their tech dept.)

Other options would be to have the motor rewound and new bearings fitted or find a similar unit that still has a readable data plate.