No 24vdc

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No 24vdc

Postby xkxlxkx » Wed Feb 01, 2012 3:43 pm

Hey Ductman! I'm a complete HVAC novice, I could really use your help. (forgive me if I'm not describing things properly)

I have a 2008 Comfortmaker (model FEM4X3600A). I Came back from vacation and the coils were frozen and the fan wasn't running.
After thawing and restarting the unit, the blower motor(GE X-13 ECM by Regal Beloit) would just vibrate. (not rocking back & forth, but vibrate and move the fan slowly in one direction at serveral-second intervals)

A voltmeter tells me I have 120 VAC on both legs at the motor, as well as 240 VAC across both legs.
Same thing at the transformer...120 on both legs, 240 across both...I'm getting 24 VAC across the secondary transformer windings.

I do NOT read any DC voltage at either the board or the motor...or anywhere else.

Could my board (diodes/relay) be toast?...Or am I barking up the wrong tree? (no visible damage to board)...incidentally, there are 2 diodes on the board...I get 36 VDC on both sides of one diode...the other diode reads 36 VDC on one side and nothing on the other

Am I even headed down the right road? Anything else I should be doing? (My brother is an electrical contractor, so I have electrical help)

Any help is greatly appreciated. Thanks in advance for sharing your expertise online.

Chris - Sarasota, FL
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- No 24vdc

Postby Freon » Wed Feb 01, 2012 4:55 pm

Most likely it's the run capacitor on the blower motor. If you have the motor energized and try and spin it, does it run (spin) but very slowly? If yes, then get a new run capacitor... they're about $10. BE SURE TO GET THE IDENTICAL CAPACITOR as far as microfarad go. The capacitor's voltage can be more then the current capacitor but not less.
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- No 24vdc

Postby xkxlxkx » Wed Feb 01, 2012 6:21 pm

I'm probably confusing myself and future readers...I'll edit the original if anybody thinks I should.

Forget all the diode stuff -
I had good low voltage at tranformer but not at motor... I was curious as to what the next step might be.
..but I think I've figured it out.

this x-13 motor is driving me crazy. I fix my pool motor or it's cap every few years and I was hoping this would be very similar...but apparently this blower motor aint havin' none of that.
I let myself get confused reading what i could find on the motor...it'll communicate on either 24v AC or DC...maybe between not reading carefully enough and/or only testing for DC at the motor, I sent myself down the path.

long story short...the motor has hi & lo voltage...spins freely when the airhandler is energized.
When the Tstat is engaged, it makes a slow, jerky 3/4 revolution over a period of about 3 seconds...pauses for about 5 seconds...then repeats.

Looks like you're right...but this is a sealed-up-guts motor...pre-programmed...not field programmable...OEM only...locate a dealer...everything I learn about it sounds like money.
...and I'm told they cost about as much as a cheap airhandler with a blower motor in it..

I guess I'll be looking into just replacing it (not sure if I can get just the control module for the motor) Or take it in to where I get my pool/spa motor/cap stuff and see what they think (Rexel Mader in Bradenton, FL)

Thank you so much, and I'll appreciate anything anybody might add.Some other online experts recently narrowed-down a bad fuel injector for me... I'm really grateful to the pros who share their knowledge and experience to help other people.
Thanks again!
Chris
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- No 24vdc

Postby heatseeker » Thu Feb 02, 2012 12:08 pm

you have an modulating motor. How old is it and is it under warranty? The motor or electronics are shot you need to replace it. Only the manufacturer will have it. good luck- very expensive.
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- No 24vdc

Postby mr151 » Wed Feb 15, 2012 4:03 am

dont drive yourself crazy i replace 3to 5 x13 motors weekly they are put in several different manufactures units the rip is the the cap is internal and u cant test it so u have to either replace the module or the entire motor very expensive 300-500.00 in miami to key west total rip. that motor should be recalled or taken off the market im not a fan of extended warranties but if u have to buya replacement x13 i reccomend it. or replace it with a non varible speed motor for about 125.00 maybe cheaper where u live goodluck
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- No 24vdc

Postby heatseeker » Wed Feb 15, 2012 9:20 am

If you know so much about the motor why are you asking for our help?
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