AAAACK! Blower motor in my house went out!

[TNToy]

Got back last night from vacation (gone 5 days), to a cold house, a weird buzzing sound, a horrible burning smell, and a really hot blower motor.

Killed the power to it, pulled the cover, and touched the blower motor. Hot! According to my programmable thermostat, the unit "ran" for 23h 37m the previous day, so it was probably doing this for quite a while.

This is an old (original, home built in '74-76) heat-pump style unit with emergency heat strips. Everything is running correctly, except that the blower motor just produces a very loud hum/buzz when it's powered up. The evaporator is getting hot to the touch, and the compressor can be heard running outside. So it's fine, except that it isn't moving any air.

When we got home, I got it to run by pulling the cover, turning the thermostat back on, and spinning the fan by hand to give it a push-start. It sloooowly spun up to speed, and proceeded to start up just fine the next half-dozen cycles of the unit. Went to bed, and at 4 AM I was awoken by the buzzing noise again...

But now spinning it over by hand won't help, and I'm tired of it being 61 degrees in here, although I'm glad that I live in the south, so it's not -20 outside. I checked it over for loose wires, and basic obvious visual stuff, since I know nothing about HVAC. Found a bad crimp on the black wire running to the motor, but re-crimping it made zero difference.

Any help?

 

[Dave Carney]

If that's the original blower motor, that's a good bet, I'd replace it, and if it has one, the capacitor. This guys website is pretty good. It's all I had when I replaced the outdoor unit's fan, capacitor, and contactor on our heat pump a few years back.

http://toad.net/~jsmeenen/motor.html

 

[CraigFL]

You can also find cheap blower motors at www.grainger.com or www.mcmaster.com and they will ship quickly if you need it. They are pretty much universal. Look at the nameplate, measure the shaft and follow the catalog information to get the one you need. As Dave said, get a capacitor too...

 

[bmwpower]

Check the circuit that your blower motor is on. That sucker probably should have tripped the breaker. The last thing you need is for it to cause a fire.

If all the previous links don't help, try www.selfhelpforums.com...worked for me.

 

[rickairmedic]

TNToy your blower motor has had a long life and I will now pronounce it DOA time for a new one . I would say you could probably replace it yourself not that hard take the old one out and make sure to wire the new one back up like the old one and yes replace the capacitor while your at it look in the yellow pages under heating suppliers wholesale you should have a grainger or Johnstone supply nearby who can help you with the new items .I better add DOOOOONT touch the connections on the top of the capacitor before shorting them out with a screw driver after you have killed the power to the air handler.

Rick

 

[TNToy]

Just got done pulling the motor so I'd be certain to get a correct replacement part: Everyone needed the HP rating, RPM, shaft dia, etc...

The motor was pretty much new. Previous owner said she'd had something replaced in the furnace. Clearly it was the blower motor, it's the only thing that wasn't covered in rust.

However, it was bound up BAD. Definitely the problem. popped it open - not much I could do once I looked at how it was made. Pretty much hit it with compressed air, greased the rear bearing, and called it good. I hooked it up once it was reassembled (bare, just a motor and wires)...

And it still didn't work. Buzzed like crazy, but was frozen up. It turns (but not anywhere near smoothly) by hand - but I guess I'm stronger than the motor that cranks it.

So I figured out which way it WANTED to go as it lay there buzzing, and chucked the sumbitch in my cordless drill. Spun it for about a minute, and then tried again. It works now. Now I just gotta get it back in the assembly, and bolt that back into the furnace.

I'm really glad this is in my downstairs hall. If it had been in my attic like our home in Chicago, I'd be ready to strangle someone right about now. So sometime in the next few days, I'm going to get a new motor. But until then, this one's going to be spinning non-stop.

 

[TNToy]

Halfway though bolting it back in. Thanks for the help...

Needs one of these:
http://www.grainger.com/Grainger/items/4VA14

And one of these:
http://www.grainger.com/Grainger/items/2GE76

Hopefully they'll last longer than the older, brand-new ones.

 

[6768rogues]

If the thing is 30 years old, I would replace the entire system, especially if you are away from home regularly. You are pushing the envelope for the useful life of the equipment, and its energy efficiency is not what a new one would be.
Trash it and buy a new one before it nickel and dimes you to death.

 

[rickairmedic]

TNToy the price on that motor is scaaaaaaaarry . I can get that motor and cap for $65 - $75 bucks any day of the week granted you will prolly end up paying rettail **** still $169 for an AO smith motor Daaaaaaaaaaaaaaaaym thats nuts I can get a GE with the cap from the trane dealer for $75 bucks any day.


Rick

 

[jay50]

TNToy the price on that motor is scaaaaaaaarry . I can get that motor and cap for $65 - $75 bucks any day of the week granted you will prolly end up paying rettail **** still $169 for an AO smith motor Daaaaaaaaaaaaaaaaym thats nuts I can get a GE with the cap from the trane dealer for $75 bucks any day.


Rick

Agree, Grainger price is out of line. Local Grainger store is over priced as well with most items.

 

[Franz©]

1) couple drops of oil every few months on the motor bearings works wonders.

2) you said rust- that generally means there will be rust between the rotor and stator of the motor. You get enough rust the flux diminishes, the motor stops turning. Eventually the rust builds sufficiently to hold the motor.

Scrub the magnetic surface of the stator with skotchbrite and apply a film of oil.
Scrub the barrel of the rotor and applya film of oil.

Reassemble the motor. Should spin like the day it was born unless the start winding cooked.

 

[CraigFL]

Agree that Grainger prices are higher but they can provide next day delivery and if you live in a small, isolated area like I do, it's the best bet if you need to get going quick.

If you opt to fix your old motor, you should check amps after it's installed. Should be less than nameplate or you will be having trouble again. Even so, it's a risk because as the motor was seizing up, it was getting VERY hot and winding insulation was breaking down.

A lot of these motors are oil lubricated and need to be lubed a couple times a year to keep them going-- make sure oil ports are facing up when mounted.

 

[Freejack]

TNTToy, I am a product manager for HAC Replacement motors, PM your specs to me, and I can tell you what some of the different replacement possibilities are.

Jake

 

[TNToy]

I'll just go ahead and post 'em...

Everything I know for certain about the motor:

Emerson Motor Technologies, Made in mexico
1/3 HP
Model KA-55HXSMW-2346
115v, 60Hz, 5.0A
1075 RPM, 3-Speed, Thermally proteced
Frame 48Y
Band-style mount
1/2" diameter shaft, needs to be about 3" long minimum.

Capacitor:
7.5 m-farad 370V

 

[TNToy]

Reassemble the motor. Should spin like the day it was born unless the start winding cooked.

Oh, the windings are black. No doubt about that.

But I installed and ran it yesterday like I said. Kept the house nice and toasty... Until 3:30 this morning.

"Honey, wake up... It smells like something's burning"

Dammit.

Shut it off, killed the breaker, opened all the windows for a few minutes (smell was INCREDIBLY strong), and went to bed.

So now it's cold in here again. A loud buzz from the motor, and after the way it smelled, I'm not even going to bother trying to run it any more. Yeeech.

I found this motor that's far more reasonably priced at Grainer, and is a better match to the RPM and motor-speed than the expensive one I had found...
http://www.grainger.com/Grainger/items/4KA34

I'm going to call them on Monday, and just cross my fingers that the store here in town stocks it. I can't find anyone else in town that sells HVAC components wholesale to the public. Didn't see anything on the Lowes/HD websites, either.

Otherwise... Unless one of you has a better idea, I'll be waiting on it to ship while it drops into the 20s on Monday night.

 

[rickairmedic]

I just noticed something that has me wondering a bit and I do this for a living . You have electic heat AKA an air handler it should have a 220 motor in it not a 110 TNToy see if you can get me a make model and serial number off the air handler itself and I can get the right specs ofr it . I would say it sounds like somebody jerry rigged that motor into your unit .


Rick

 

[SteveU]

Try www.heatingandcoolingwarehouse.com they have a 1/3hp emerson 1075 motor for 77 that might work?

 

[TNToy]

Rick, thanks for the warning.

The home came with a 1-year warranty, and a local company does all their service (I've had to have a relay and another small repair done under the warranty). I avoided re-upping the warranty because I have intended to someday replace the whole unit. Those guys are also the ones who installed the motor for the previous owner... I know this because it had their sticker stuck to the side of it, in a place you couldn't possibly access without pulling the motor. I can easily see them rigging a random blower they already had on the truck into the thing.

I *did* intend to replace the whole air handler, but that's much easier to say when you're deciding to allow a warranty to lapse, than it is when you're looking at immediately purchasing a $2K unit, versus a $100ish repair.

Rick, I'll get you that info tomorrow. I finally found the panel with the wiring diagram lying next to / behind the bottom of the unit. So tomorrow I'm going to compare what *should* be there, to what is actually present. I've got more than enough experience chasing electrical nightmares through poorly-modified cars that roll into our dealership... and looking at this thing has my nose twitching, if you know what I mean.

 

[rickairmedic]

LOL TNToy I know what you mean also the data plate on the furnace same place you find the model and serial may give you some insight as to what motor came with that beast as compared to what they put back in it . I am not saying its the wrong motor I just dont ever remember seeing a 110 motor inside a 220 air handler .

Rick

 

[Freejack]

TNTToy,

Given your specs here are your options, these are all Emerson Catalog #s:

1864: http://apps.motorboss.com/Dimensions/FHP/V01257349.pdf
5460 RESCUE Multifit motor: http://apps.motorboss.com/Dimensions/FHP/V01728974.pdf

The latter motor is actually rated up to 1/2 hp and has an extra speed tap, but would work fine in your application.


If its a 220V:

1972: http://apps.motorboss.com/Dimensions/FHP/V01257369.pdf
5461 RESCUE Multifit motor: http://apps.motorboss.com/Dimensions/FHP/V01729375.pdf

Check with the local HVAC supply houses, many carry Emerson motors.

Jake

 

[TNToy]

Awww ****...

I just finished installing the new motor and capacitor. It's doing the same damn thing. Motor produces a loud buzzing noise when turned on. It just sits there humming, but if you spin it over by hand, it'll spin up to speed and operate normally, until it's turned off.

My thinking is that the motor isn't being supplied with enough current, since starting is obviously the event that causes the largest current draw. I'm going to go poke through the wiring diagram, and then see what happens when I jumper the leads on the relay. I really wish I hadn't left my multimeter at work. Now I won't be able to use it until Wednesday. Might be time to go buy a multimeter for the house - I've been meaning to for a while.

I'm pretty much leaning toward getting a few estimates on replacing the entire air handler... I'm sick of this thing breaking at the on-set of every cold-spell and heat-wave, and the astonishing amount of rust on the evaporator/condenser (I guess it's both, depending on which way the system is working) does NOT inspire a lot of confidence in it's remaining lifespan.

I think I'm going to get some quotes on replacing this thing.

Can they clean all the **** out of our ductwork/vents when they replace it? I've probably got some of the dirtiest vents I've seen, and it'd probably be great for my wifes allergies if I could get rid of all the mold and crud built up in there.

 

[Franz©]

Why not just take the easy way out for the moment and switch the system to constant fan? Spin it up by hand if you need to.

When is the last time the blower shaft was lubricated?

Cleaning the ducts at this point would probably be the worst possible situation in terms of allergys. Contrary to all duct "cleaner's claims, it generally takes a couple weeks for the level of airborn contaminants to drop off after duct cleaning. Ducts should be cleaned when the house can be open to outside air for maximum air exchange.

 

[TNToy]

Forget that post. Played with the stupid thing for another couple of minutes, and found a broken wire coming off the capacitor. Working like a charm now.

 

[rickairmedic]

TNToy glad to hear your back up and running .


Rick

 

[TNToy]

Heck yeah.

The last few nights weren't really all that bad (low in high 40s/low 50s)... But it's going to be 25ish here tonight. And I'm very glad it's fixed.

I almost wish I would've just replaced the air handler instead of spending a paltry $75 to repair it. At this point I'm buying time measured in months, not years, by throwing parts on it.

 

[Franz©]

Why are you calculating the remaining useful life in months rather than years?

Think of it as an opportunity to contend for the 2008 Tim Taylor Mr Fixit Awards.
Think of the adoring looks from Jill. The envy of the neighbors who max out their mechanicle skills opening the car door.

Whip on over to Horror Freight and buy yourself a new toolbelt with double battery drill holsters. Who knows the rechargable LED troublelights might be on sale too, and those are nice for furnace work.

For the love of doG, MAN UP, TOOL UP, plan ahead.

 

[rickairmedic]

TNToy I am glad you got it up and running again and you probably have some time to deal with your system before you start freaking out . I will tell you the same thing I tell alot of my customers with older systems ( start planning now ) start putting money away in a household only account so that when its time to actually deal with it you have money set aside for the new system . I can also run some programs for you to help in deciding on that new system . I will tell you top of the line top dollar system is not always the best bang for the buck . I sell Carrier equipment and wouldnt sell anything else to most of my customers but I also dont push the top of the line equipment they offer as I dont feel the payoff is there for my customers in the longrun . I have sold a few high end systems to customers who had and wanted to spend the money regardless of the fact the system would pay for itself in the long run . I will say I do alot of Duel Fuel systems here and it may be something for you to look into your weather should be similar to what we have here in Louisville. Let me know if I can help with design or pricing in the future.


Rick