Home Air Conditioner question

[Rondar]

I have a Miller A/C condensing unit approx 15 years old.  The model number plate is sun faded and cannot read the paper tag.  However, I can see that the condenser fan motor, which is what I need because the bearings were stiff and motor turned kind of hard, is 1/4 hp and is 825 rpm.  What kind of problems will I have if I put a 1/3 hp fan on at 1075 rpm?  There just seems to be a lot more 1075 rpm motors than 825.  Fan is a 2 blade and I believe my unit is about 3 1/2 ton.

I took the motor off of the condensing unit and drilled a small hole in the end bell where the cap holds the felt pad for oil lubrication and I put turbine oil in it.  It is running fine now but thought I should be looking to have a motor sitting around if this one quits.  Its 95 to 100 degrees here this time of year and dont really want to be without it.

Part number(s) on the fan (what was not faded) were ...  GE Motor 5KCP39FF  then another mfg #6213050.   Some of the replacement motors from a few places I looked online at were 250-290 dollars.. utterly rediculous. 

[NOT]

increasing motor rpms will mess with the efficiency of your unit. although technically possible, you would need to have your refrigerant charge adjusted. that motor shouldnt cost more than 100-150. check your local AC supply houses, ask around and see if anyone you know knows an AC man who might help ya out. most companies will charge 300-500 for fan motor replacement. good luck




NOT

[wrongwayric]

Well if you oiled it, it might get you through the summer, but yea the prices you were given seem really high. NOT is right you want to use just as close to the original RPM's as possible, as they design the unit, then put the motor in that provides the most effective/efficient cooling for that unit.

[gunnss]

As I understand it you are talking about your condenser fan motor, that is, the motor that runs the fan that pulls air through your condenser coil. replacing the fan motor with a higher HP and RPM unit will not really affect the condenser very much. (it will burn a bit more power if that is a concern) However if you are talking about your "Compressor" motor you may have a problem. On the griping hand it sounds like your lube fix is working just fine, just do a weekly check to see if it has stiffened up and needs more oil.

Regards,
Kevin
 HVAC guy to the feds... (Grin)

I have a Miller A/C condensing unit approx 15 years old.  The model number plate is sun faded and cannot read the paper tag.  However, I can see that the condenser fan motor, which is what I need because the bearings were stiff and motor turned kind of hard, is 1/4 hp and is 825 rpm.  What kind of problems will I have if I put a 1/3 hp fan on at 1075 rpm?  There just seems to be a lot more 1075 rpm motors than 825.  Fan is a 2 blade and I believe my unit is about 3 1/2 ton.

I took the motor off of the condensing unit and drilled a small hole in the end bell where the cap holds the felt pad for oil lubrication and I put turbine oil in it.  It is running fine now but thought I should be looking to have a motor sitting around if this one quits.  Its 95 to 100 degrees here this time of year and don't really want to be without it.

Part number(s) on the fan (what was not faded) were ...  GE Motor 5KCP39FF  then another mfg #6213050.  Some of the replacement motors from a few places I looked online at were 250-290 dollars.. utterly rediculous. 

[Speed55]

http://www.grainger.com/Grainger/wwg/productIndex.shtml?operator=keywordSearch&search_type=keyword&QueryString=GE+Motor+5KCP39FF++&submit.x=16&submit.y=13

4m226 looks like the best match.  - the 2nd one down.

You could call them to verify, and i don't think you need any hvac license, or account to buy from them.

Good luck.