Carrier Blower Motor Problem


  #1  
Old 06-29-16, 04:22 PM
G
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Carrier Blower Motor Problem

Hey fellas,

I've got a bit of a no A/C situation here on my hands. I live in Atlanta and OF COURSE the thing waits for the weather to hit 100 before breaking!

I've got a carrier heat pump. Currently, the compressor works but the blower motor will not come on. I had the local come and service the unit and they explained that the blower control module was out. Repair cost? $1,350. OUCH!

The guy was nice enough to give me the part number, HK44ER136. $340 online. I'm an electrical engineer so the guy said I could probably tackle installation myself.

Part arrived today and I swapped them out. The fan motor still will not come on. I did the service checks on the motor and all the resistances checked out in accordance with the instructions.

I rigged up an external stand so I could test the motor while it was in situ. I have voltage going into the control module and voltage coming out of the control going to the motor.

Is there anything else I can do to try to fix this guy? If I need to replace the entire motor assembly, is there a cheaper alternative than the fancy pants one I have in here?

The unit is pretty old but I'd like to keep it going until the fall.

Thanks!

E
 
  #2  
Old 06-29-16, 05:20 PM
Bob14525's Avatar
Member
Join Date: Jun 2013
Location: USA
Posts: 1,754
Received 57 Upvotes on 48 Posts
Is this an ECM or X13 motor? If so, you could try replacing it with a PSC motor. If it is an ECM motor, there is a control module on the back of the motor (what I assume you replaced), however there is also some control circuitry on the control board as well. If the motor resistance is good, and you have a new motor control module, then there's a reasonable chance that the control board (what connects to the motor control module) is bad.
 
  #3  
Old 06-30-16, 05:49 AM
G
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Hey Bob,

It is an ECM motor. I've attached the pictures of the unit.

Is there any way to jump the pins of the controller to get the unit to spin?

The main control board was replaced last year. If I could just limp this thing until fall that would be fine, as I'm planning on replacing it with my renovation

Name:  IMG_20160630_063121.jpg
Views: 1198
Size:  19.7 KB

Name:  IMG_20160630_070206.jpg
Views: 1272
Size:  47.8 KB

Name:  IMG_20160630_070219.jpg
Views: 1403
Size:  49.9 KB

Name:  IMG_20160630_070229.jpg
Views: 1246
Size:  45.0 KB!

Any advice is appreciated, no matter how hacky!

Thanks,

E
 
  #4  
Old 06-30-16, 06:07 AM
Bob14525's Avatar
Member
Join Date: Jun 2013
Location: USA
Posts: 1,754
Received 57 Upvotes on 48 Posts
I was afraid you might have an ECM motor (I have one in my furnace as well). I'm not an expert on these things, but unfortunately, I don't know of any easy way to get the motor to spin. When the control module on my motor died (burned up thermistor), the technician who came out to diagnose it (thankfully, it was under warranty) mentioned that there is a tester for these ECM motors. He didn't have one with him, but he said that some of the other techs from his company had them. Perhaps you could call some heating/cooling contractors and see if you can find one that has a tester and bring your motor there to get it tested. If the motor tests good (which it probably will), then I suspect the only thing left is the control board.

Since you're an EE (so am I), my understanding of how these motors work is that it's similar to how stepper motors are used as motors in different devices. They need to be ramped up & down and the different phases energized to create smooth motion. I don't know how much of the control circuitry exists in the motor and how much on the control board. I suspect that the control board does a lot of the "switching". On my furnace, the motor speed is continuously variable. I believe that the control board controls the speed by controlling the phase switching on the motor. I believe the motor control module just contains the "power electronics" required to drive the windings of the motor, while the timing is controlled by the furnace board.
 
  #5  
Old 06-30-16, 07:28 AM
G
Member
Thread Starter
Join Date: Nov 2014
Location: United States
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
So this guy has a great series on these ECM motors:

https://yorkcentraltechtalk.wordpres...ooting-part-1/

I'm going to follow it tonight and see what's going on.

Thanks!

E
 
  #6  
Old 07-02-16, 10:03 PM
H
Member
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,856
Received 1 Upvote on 1 Post
Testing ECM motors

YouTube has a load of vids how to trouble shoot them, do a search there see how to test the board, the leads, signal... The tester can be bought too to prevent buying something costly when not needed, and the small booklet with it. It's like $30
My buddy saw the cost of one of these, then called the dealership and said send me a standard PSC motor instead.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: