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Thread: Motor or ECM

  1. #1
    Join Date
    Jan 2012
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    10

    Motor or ECM

    I have a Carrier Air Handler (FV48NF003000AAAA) inside the house. The blower motor will no longer start. It is possible that over the last several weeks it may have been starting and shutting off but I can't be sure. The fan spins freely but there is a humming and the cage gets very warm. I didn't touch the actual motor so it may be that the heat strips were warming up the cage.
    Anyway, a tech came in with 2 motor testers which were supposed to eliminate everything outside of motor itself. It would not start. He then ohmed the motor at the connector and got a bad result (don't know the exact readings). Is there a way to tell if it is the motor itself or the ecm on the back of it? I removed the cage and the back of the motor. Everything looks good visually. There is some white goop between two capacitors but it looks like spillage from another component that was used to mount the other component. My costs, motor with ecm =about $, ECM by itself about $.

    Also, is it normally necessary to use a pulley puller to remove the motor shaft from the fan?Name:  Goop.jpg
Views: 477
Size:  47.6 KB
    Last edited by beenthere; 03-28-2013 at 08:59 PM. Reason: Prices

  2. #2
    Join Date
    Aug 2007
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    Northern VA 38 degrees N by 76 degrees W
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    5,058
    Quote Originally Posted by glennroe View Post
    I have a Carrier Air Handler (FV48NF003000AAAA) inside the house. The blower motor will no longer start. It is possible that over the last several weeks it may have been starting and shutting off but I can't be sure. The fan spins freely but there is a humming and the cage gets very warm. I didn't touch the actual motor so it may be that the heat strips were warming up the cage.
    Anyway, a tech came in with 2 motor testers which were supposed to eliminate everything outside of motor itself. It would not start. He then ohmed the motor at the connector and got a bad result (don't know the exact readings). Is there a way to tell if it is the motor itself or the ecm on the back of it? I removed the cage and the back of the motor. Everything looks good visually. There is some white goop between two capacitors but it looks like spillage from another component that was used to mount the other component. My costs, motor with ecm =about $, ECM by itself about $.

    Also, is it normally necessary to use a pulley puller to remove the motor shaft from the fan?Name:  Goop.jpg
Views: 477
Size:  47.6 KB
    99.999% of the time it is the control module and not the motor
    Last edited by beenthere; 03-28-2013 at 08:59 PM. Reason: Removed prices from quote

  3. #3
    Join Date
    Aug 2009
    Location
    Beatrice, NE
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    1,987
    The motor tests like any 3 ph motor, if the windings test good it's either the module or controler. If the windings test bad, it's bad. It is possible that the motor and module are bad at the same time but not likely.

  4. #4
    Join Date
    Sep 2005
    Location
    Atlanta GA area
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    20,896
    Did the tech say it was the motor or module?

    Posts #2 and #3 are correct information... issue is usually not the motor.

    We are in an age where one needs gadgets to test the gadgets...
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  5. #5
    Join Date
    Jan 2012
    Posts
    10
    He said motor and never mentioned the ECM. If you ohm from the connector on the outside of the motor, isn't the ECM between the connector and the actual motor? If so, that is why I would like a way to tell which it is. Like I said, if I buy the motor I will get a new ECM included. If I buy just the ECM and that is not the problem I am stuck with a $ part that I don't need. Since I have now been able to locate the complete motor for $., I am thinking that I might be better off buying the complete thing for $ instead of just the ECM for $200 and then have a 7 year old motor. That is unless I can find a way to test which it is.
    If I disconnect the ECM from the motor I have a red, a blue and a black. What should I read there to know the motor is good?
    Last edited by beenthere; 03-28-2013 at 09:00 PM. Reason: Prices

  6. #6
    Join Date
    Jan 2012
    Posts
    10

    Motor Looks Good to Me

    I disconnected the 2.5 HP motor from the ECM. Between each of the 3 wires on the motor I get 11 ohms. Between each wire and the motor case I get open.

    At this point is there any reason to believe that the motor and not ECM are at fault?

  7. #7
    Join Date
    Sep 2005
    Location
    Atlanta GA area
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    First... lets get the terminology correct: The WHOLE assembly is an ECM motor.

    The motor is the motor, the back part is the module.

    Your test suggests the motor is good. There is more testing to do beyond what you did with the 3 leads and an ohm-meter... some of it requires a gadget or two to do.

    Unfortunately, we are not allowed to disperse too much "DIY" information on this site (site owners rules).

    Most of the time you would be fine the less expensive route... however without physically being there and running the tests with the gadgets in my van (I have $thousands and $thousands of those gadgets... ) I really cannot say.

    PS: The reason heat and AC service costs a lot is all the tech stuff we have to know and all the gadgets we need to do our job.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  8. #8
    Join Date
    Jul 2006
    Location
    Virginia
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    i did not think carrier sold the componets seperatly ,around here you get the motor and module , and it is a arm and a leg
    We really need change now

  9. #9
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    Sep 2005
    Location
    Atlanta GA area
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    Something to remember: The module is an electronic gadget, it is programmed to a specific component (Carrier 100K furnace or Trane 80K air handler, etc).

    Just any old module will not work on just any box.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  10. #10
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    Sorry, prices are not allowed.

    Nor is this a DIY site. Which is clearly what you want to do.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  11. #11
    Join Date
    Jan 2012
    Posts
    10

    Sorry

    Sorry if I was ignorant the rules. I really just needed to know if it was reasonable to assume the entire motor was bad with a tech using a gadget and an ohm meter without separating the motor from the module. The module has a Carrier part number (RMOD44AE132) which is a sub part of the whole thing (HD44AE132). The module is available at multiple HVAC parts places.

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