Replace '60s GE 5KCP45 Condenser Fan Motor?
I just discovered this site while searching for an AC condenser fan motor, but with 30 years DIY in various areas, mostly auto, appliances, etc. Please forgive the ridiculously long-winded post. I'm a midwesterner, mostly in Asia these days, but returning mid-August to the states for a month. My 1913 house in Omaha has a 60's vintage American Standard central AC unit on which I've previously replaced a controller and a run capacitor. When the system runs properly, it's a little noisy, but does a reasonable job cooling the old two story house. It's used only on the hottest days, otherwise fans and good window discipline are all that's needed. The condenser fan (specifications below) last summer started shutting down after running a few minutes, though I didn't witness this as I was abroad. A service guy had been called in my absence, who said the motor was drawing too much amperage, and needed to be changed, to the tune of $400. However, I think the guy didn't realize how tough it might be to replace this motor. When I got back in Feb., I called around and surfed the web looking for a match, including the local Grainger's, but came up empty. The closest motor, not close enough, was also over $300. So I pulled the motor and took it to an elec. motor shop for an assessment. No shorts or other problems found, but after running a few minutes, the amp draw increased enough to open the internal overload switch. The tech concluded that I probably needed to replace the sleeve bushings, IF I could find them. I took the motor to another, older shop, where the owner seemed pretty knowledgable. He found no excess endplay or sideplay in the shaft/bushings, and suggested the problem might be no more than insufficient lube at the bushings, and in the felt oil reservoirs, if any. (Though I'd oiled them periodically, I had only added a few drops each season, afraid of overoiling. This was, I concluded, not nearly enough.) He said to reoil generously through the spring-capped filler tubes over the course of several days, maybe 40 drops of 20 weight non-detergent elec. motor oil in each tube. Since no excess oil ran out of the motor case, which is vented at the bottom, I assumed the felts had absorbed it.
Before returning to Asia later that month, I reinstalled the fan, thinking all was well. But when the A/C was turned on for the first time since, during the recent July heatwave, the motor displayed the identical short-run behavior. I now wonder if the felt oil-reservoirs may, over time, have shrunk away from the motor shaft and bushings, so even if holding oil, are no longer in contact with the shaft. Thus no oil can seep into the space between shaft and bushings. But I have no idea what the lubrication arrangement might actually be inside the bushing housings. When I'm again stateside late Aug., I'll investigate further, perhaps disassembling the motor to see what's what. If my guess is correct, and the felts are too distorted or shrunken to work properly, I'm hoping I can find some replacement felts at a bearing house, even if I must resize to fit, or maybe I can find felt stock from which to cut new felts. In the meantime, I'd like to have a replacement motor, if I can find a match, so I can get the system running again if the motor proves for whatever reason unrepairable. (I was told sleeve bushings for this motor are no longer available, and that the process of disassembly was quite tricky. The springs in the bushing housings, for instance, snap easily and are also irreplaceable.)
I'm aware GE 5KCP motors were OEM specific, and so far have found no matchups online for this particular model. I've emailed Emotorstore in Chicago, which might have a match, but so far no response. If anyone can help me find a replacement, and/or suggest a diagnosis and repair for the existing motor, I'd be mighty grateful. It's a three wire (two red, one yellow), open, direct drive, air over, horizontally mounted in what I believe is a NEMA 56 frame, as shown in the photo below. Here are the specs from the motor plate:
HP 1/3 FR 567
V 230 PH 1
RPM 825 CODE F
A 2.8 CY 60
TEMP RISE 50C SF 1.O
TIME RATING CONT. AIR OVER
SER. NO. RWL