Replace '60s GE 5KCP45 Condenser Fan Motor?

Discussion in 'HVAC Heating & Cooling' started by Gocon, Jul 12, 2012.

  1. Gocon

    Gocon New Member

    Messages:
    4
    Location:
    Hong Kong
    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:
    MOD 5KCP45PG50S
    HP 1/3 FR 567
    V 230 PH 1
    RPM 825 CODE F
    THERMAL PROTECTION
    A 2.8 CY 60
    TEMP RISE 50C SF 1.O
    TIME RATING CONT. AIR OVER
    SER. NO. RWL

    Many thanks!!

    George
    Last edited: Jul 12, 2012
  2. Gocon

    Gocon New Member

    Messages:
    4
    Location:
    Hong Kong
    CndnsrFanMtr.jpg Here's a photo of the GE 5KCP45xxx condenser fan motor before removal and cleaning. The ID plate has already been removed from the wire well.

    Tx. George
  3. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Try FASCO http://www.fasco.com/xref_list.asp

    But if you are expecting to find a $99 special to replace a 40+ year old motor.....good luck! By the way, Grainger is THE motor source, but may or may not help out a homeowner....they tend to be "trade only" sometimes.
  4. Gocon

    Gocon New Member

    Messages:
    4
    Location:
    Hong Kong
    Thanks for the advice Jimbo. Afraid that Fasco cross reference won't pull up a match, even if trying GE 5KCP45 or just 5KCP45. Uncertain what the remaining motor numbers might indicate. 5KCP45PG50S. I certainly wasn't expecting a $99 special, but always happy to take one. Somewhere under two hundred would seem about right. I've bought plenty from Grainger over the years, and started the search with them in Feb. Unfortunately they weren't able to find a match either, though that was all over the phone. Showing up with the actual item might have been different. Right now I'm trying to get the Am. Std. unit number so I can contact them for any possible cross reference. Anyone have thoughts about feasibility of repair?
  5. TJanak

    TJanak New Member

    Messages:
    154
    Location:
    South TX
    I had a similar problem with the motor on my old Craftsman table saw. I don't remember it cutting out but it would start making a terrible grinding noise and you would have to shut it down. I took it apart and cleaned up the bushings and shaft to get them smooth and then reassembled with some light engine assembly grease on the surfaces. Soaked the felt pieces in oil overnight or so and then put it back to together. Has been running for 6 months or so, but it doesn't run as much as an A/C unit.

    The shaft/bushings were just so dry and the felts so dirty and dry that even when I added oil to them it never soaked all the way to the shaft. I had to take them out and clean them (probably used gasoline) and soak in oil before reassembly.
  6. Runs with bison

    Runs with bison Member

    Messages:
    892
    Location:
    Midwest
    Being as you are in Hong Kong your options are probably more limited for a 40 year old unit. I suggest calling local installers to see if they have a boneyard of old parts...or if they have been replacing any of these outdoor units recently.

    Over a decade ago (probably 16 years) I had a blower sieze in a unit of about the same vintage yours would be. It just needed new bearings, but I couldn't get replacement parts. I called a couple of installers and one said he had pulled out a similar unit recently on a new install and he would sell me the old blower. I went to the shop confirmed that the bearings would work and bought the old unit. It wasn't a perfect match on the blower and pulley so I had to tear both units down to place the new mounting arms with the bearings in them on my old blower with its original pulley. Worked fine for at least 6 years, don't know after that as I moved.
  7. Gocon

    Gocon New Member

    Messages:
    4
    Location:
    Hong Kong
    Thanks Runs with Bison--Though I'm in Hong Kong at the moment, the AC unit's at my house in Omaha, where I return in a few weeks. From what Mr. Janak says about the felts in his old Craftsman table saw motor, it sounds like the plan will be disassembly and relubing. I have one of those old Craftsman saws myself, with a cast steel bed, and it's worked well for many years. Picked up a matching motor for it somewhere too, absolutely identical--can't recall, but maybe $5 at a yard sale. Many of my best tools came that way, from the era of fine Am. toolmaking. Also inherited some from my grandfather, who had his own tool & die shop behind the house. A chief machinist's mate on a WW1 destroyer at 18, he could do anything mechanically.
    Last edited: Jul 14, 2012
  8. Terry

    Terry Administrator Staff Member

    Messages:
    15,053
    Location:
    Bothell, Washington
    An email from Gocon:

    Thanks Terry. Actually this is no longer a question, but the resolution of my earlier posting. While others may benefit, I bet few will be so thoughtless as not to check both compressor and condenser fan motor capacitors. Lube was part of the issue, but the main culprit was the fan capacitor. Well, I can fix lots of things, but am not a pro. Here's the text of my post:

    Sorry for the long delay in posting the resolution of this problem, as I've been abroad. While back in states this past fall, and with the help of a very kind and intelligent elec. motor shop owner, I removed the fan from the old GE condenser fan motor shaft, then the bushing end-housings. Inside, the oil felts had not been deformed or heat-shrunk as I'd feared. But despite my earlier oiling of about a tablespoon each with proper elec. motor oil, they were still too dry. With the housings off, I oiled the felts directly until they could hold no more, then reassembled everything. When I started up the AC unit, however, the fan motor again ran a minute or so, then stopped. After an interval, it restarted, running progressively shorter each cycle. Although I'd replaced the compressor run capacitor a few years before, which had checked out OK, I stupidly hadn't checked the condenser motor's own capacitor, housed in its mounting atop the motor. Sure enough, the multimeter pronounced it bad. Replaced it for a few bucks, and the whole unit ran with no further problems. Certainly just as well I oiled the bushing felts, which I'll take care to keep lubed annually, and more generously. As the motor shop guy said, oiling's like a bank account: if you start with $100, and draw out $20 each year, but only deposit $10, you'll eventually run dry.
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