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  1. #1
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453
    Had service call to high eff. rheem unit - not sure how high the eff. is, but found bad condenser fan motor.
    Original motor was 1/16th H.P.( .45amps ), can you believe it. Two blade fan. Local Rhem supplier did not even have this motor, had to go back with 1/5 HP.
    This is one way to get eff rating. Undersize outdoor unit fan motor. Unit less than 6 yrs old

    This is one of the reasons I don't trust high eff. equipment. What are the manufacturers going to do to get 13+ seer ratings next year.

    Also have seen units whose reversing valve would energize & deenergize by the thermostat ( not the heat-off-cool switch ). Found out that that was to get higher eff. rating. Less energy usage if reversing valve was not kept energized in cooling cycle.

    What other ways do manufacturers have to 'cheat' on eff. rating ??

  2. #2
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,182
    How do you know 1/6 hp was undersized? Pretty rare to see a 1/3 hp fan motor any more. Some brands go 1/8 - 1/10 hp these days. Use an Emerson Rescue motor and you can adjust hp from 1/3 to 1/6. Mounts fit Rheem outdoor units too.

  3. #3
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    There is equipment out there that has spinning low pitch 16" 4 blade fans at 825 RPM with a 1/6 hp motor for 15+ years without problems.

    If the condensor coils are kept clean, and the unit is located so water running off the roof doesn't go in the top of the unit, those motors last as long as any others.

    The problem with Rheem/Ruud outdoor units is that they seem to act as yard hoovers more than most other brands. It is very rare that I see one on a service call that doesn't have a filthy condensor coil. Restricting the airflow through the condensor coil is a good way to kill a condensor fan motor.
    If more government is the answer, then it's a really stupid question.

  4. #4
    Join Date
    Apr 2004
    Posts
    7,680
    Seems to me the motors are selected based on airflow requirements through the outdoor coil and no reason to overpower them. Next time you look through your spec books at the efficient systems, look at the latent/sensible ratios of that rheem you didnt like compaired to others, look at the HSPF's of the heat pumps compaired to others. While your at it, notice it doesnt require a time delay or, liquid line solenoid valve in order to achieve SEER ratings.

    Its too bad your distributor didnt have the motor in stock but he probably didnt want to sit on it for 4 years waiting to sell it when he can stock a trip-saver motor that can get you back on line.

    Cleaning coils is part of owning an air conditioner. Its a fact of life. I'd far rather work on a unit with all the componants right there in front of me than one where I have to keep blocking the service panel after attaching my instruments anyday. If yeard debris is an issue, dont be affraid to stick some pump-ups under the unit to get it up off the pad a little.


  5. #5
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453
    Its not 1/6 u guys

    It is 1/16th hp

  6. #6
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,182
    Looks like we all need glasses. Never seen anything that small. Remember the model #?

    Rheems do get dirty easy BUT with large footprint and wide fin spacing, much of that is surface dirt. The ones that really have a problem are the little cubes that are so popular. To get the small footprint, they use very tight fin spacing which lets the dust pack in between the fins. The rain washes the surface so homeowners & techs think the coil is clean when it is really packed.

    I don't know that "cheating" is the right term for these techniques. With rising energy costs plus the new 13 SEER requirements, manufacturers have to use every method they can to drop the juice usage while keeping reasonable peformance. Also cheap homeowners are demanding cheap units so they also have to use the most cost effective methods they can do get this high SEER. If customers didn't mind spending a little extra on their HVAC, we'd really have some nice products instead of cheaper built, less reliable stuff.

  7. #7
    Join Date
    Apr 2004
    Posts
    7,680
    Yeah, what model was it, the lowest I see is .9 fla at 230v. Some 460v might have a fla of .6 but I dont see any with a .45 fla... Sure it was original motor?

  8. #8
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453

    Rheem model;

    The model # rpfb-024jas

    The motor wiring seemed to be original, as was the rust around blade hub. unit less than 6 years old

  9. #9
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,182
    That's an old 9 SEER so would date before 1992. According to the parts list on Rheemote, the factory motor was a 1/5 hp, 1075 RPM single speed.

  10. #10
    Join Date
    Nov 2001
    Posts
    406
    he said 4 years

  11. #11
    Join Date
    Mar 2004
    Location
    Grottoes VA
    Posts
    5,856
    That is not a 6 year-old furnace. The S in the JAS tells you it is a tin can comp. Rheem hasn't used a tin can for 10 years or so.
    Karst means cave. So, I search for caves.

  12. #12
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,944
    I remember these motors well. They were OEM installs that were never used for replacement parts.

    If memory serves me, they were also mounted by three screws that went through the motor and the replacement motor has 4 screws that tap into the side of the motor.

    Many types of games are played to create slight efficiency changes. The lack of a crankcase heater can get some units over the fractional hump they need to reach the next SEER level. Variable speed blowers are a very good efficiency booster. Even though a 90 second time delay for indoor blowers is bad for humidity control, it adds .2 SEER to the rating.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  13. #13
    Join Date
    Sep 2001
    Location
    East Stroudsburg, PA
    Posts
    13,215
    Originally posted by karsthuntr
    That is not a 6 year-old furnace. The S in the JAS tells you it is a tin can comp. Rheem hasn't used a tin can for 10 years or so.
    HUH????????

    They still use tin cans in their low-end units.

    The scroll in the 10 seer is an option.

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