Can this blower motor be fixed?

rsilvers

This motor spins up sometimes, but the fan has partially detached from the motor, or the motor shaft is messed up. I can push the fan side to side about 2 inches.

I can't figure out how to remove it to replace the motor assembly. This unit has no side panels that come off to access it, and if I look at the way this blower is bolted in, it doesn't look like it is possible to unbolt it due to how it was assembled at the factory.

Are these meant to be serviceable? Do I need to cut a huge opening in the side so that I can get to the motor and then patch that over later?

mattmia2

The whole blower assembly unbolts from the bottom of that partition and pulls out the front somehow, usually on tracks or keyhole slots. Be careful not to drop or rest it on the evaporator in that process. Might need to rotate it in some direction to make it fit out the front.

mattmia2

what's behind that panel that is missing 2 screws? looks like that might come apart then the blower slides out.

JUGHNE

Reach inside the right side of the blower wheel and find the motor shaft.

There is a single bolt in the wheel hub that locks the wheel in place.

It is usually a square heat bolt about an inch long.

It is probably loose. There is a flat side on the motor shaft.

The wheel hub bolt needs to land on this flat.

You center the wheel in the blower housing and tighten the bolt.

There is end play in the motor shaft so you want to reach the happy medium of location for the wheel.

I get it set and then push the shaft in and rotate the wheel to check clearance.
Then pull on the shaft and rotate for the same clearance.
The in and out of the motor may be a 1/4" or so.

To remove the entire assembly, there are either 2 or 4 screws on the top rails of the blower housing. Remove them and the blower will slide out. Of course you must disconnect the wires from the motor.

Then you will see what holds the motor in place. You have to loosen the hub setscrew/ bolt to pull the motor away.

The blower housing has a small section that can be removed with screws and the wheel will come out if needed for cleaning etc.

Your motor shaft may be chewed up and not hold the wheel in place.
But try just relocating the wheel and tightening up the bolt/set screw.

mattmia2

Check the motor shaft itself for excessive movement up or down or toward the front or back, the bearings could be worn out if there is a lot of endplay.

mattmia2

Oh, and is that little folded up piece of paper in that pocket service instructions?

SuperTech

You need to unscrew and remove the entire electrical box with the control board or relays and transformer and remove it. There's a few 1/4" screws on each side. Be prepared to rip up the insulation a bit if you are not careful. 

First CO air handlers are a pain in the butt to service the blower assembly because of this. You have disconnect and reconnect every wire in the air handler.  

One good thing is your unit isn't horizontal. It's a lot of fun removing those screws that hold the electrical box when you can't get to them....

HVACNUT

Remove the electric compartment after disconnecting the motor leads from it.

The whole blower assembly slides out on a track after you remove the 4 screws holding it in the track.

Sounds like the hub is detaching from the fan. If so you'll need a new fan. If the motor repeatedly locked out on thermal overload because it couldn't turn, it might not be a bad idea to replace the motor and run cap at the same time. 

If you're reusing the motor, you might need a puller to get the fan off the shaft.

SuperTech

@HVACNUT is correct.  One other thing I would consider, if you have an older model that doesn't have the CB201V circuit board and has the relays instead upgrading to the circuit board is not a bad idea.  In my experience the heat sequencer relays in the older models have a high rate of failure.

Hope this helps. 

rsilvers

You guys helped a lot because you showed me it can come out. I removed the electrical panel, which was a bit of a pain as the installer thought it would be a good idea to bolt the power cutoff switch over the screws that hold in the controller section. I disconnected the wires after labelling them all.

But now my problem is that I cannot slide the blower out all of the way because numbnuts thought it would be a good idea to run the hydroponic and refrigerant lines straight up the front. In theory I can cut and patch the hydroponic line, and bend the refrigerant line out of the way. Of course I want to avoid doing that.

I found the motor shaft, and I am having a hard time aligning the hamster wheel onto it. I assume I have to get it up and pushed into the motor, and aligned on some kind of indexing feature. But that is hard to do because I cannot grab the motor shaft to keep it from rotating with the blower wheel.

rsilvers

I found photos of what this stuff looks like, and it is a bit different than I imagined. It seems like the square nut being tight is required for it to be aligned.

I had expected the blower would wedge up onto an indexed-taper or something for alignment.

pecmsg

You need a wheel puller
or
get the shaft exposed and sand it down. 

rsilvers

The liquid refrigerant line looks like I can bend it due to how much slack there is at the ceiling. The other vacuum line is 3/4 (7/8) and is a problem.

rsilvers

Maybe I need to cut a giant access door on the back and maybe this blower can slide out the back?

rsilvers

I wonder if 25 year old refrigerant is degraded? If I did remove it, would I want to put it back or only put in new refrigerant?

HVACNUT

rsilvers said:

Maybe I need to cut a giant access door on the back and maybe this blower can slide out the back?

No. Please don't. 
 There's no straps along the ceiling holding the refrigerant lines you can loosen? You only need 🤏 much more. You can do it. Don't kink it.

mattmia2

rsilvers said:

I wonder if 25 year old refrigerant is degraded? If I did remove it, would I want to put it back or only put in new refrigerant?

There is a process to pump the refrigerant down in to the condenser if it has service valves but you need tools and skills that you don't have to do that.

You should be able to bend the tubing off to the side to get clearance, be careful that the tubing bends and that it doesn't unscrew any threaded fittings at the evaporator or twist the tubing in the evaporator.

While you have the blower out, put the capacitor in the bracket on the side of the blower instead of laying in the side of the cabinet. A few quality zip ties would be a good idea too to make sure non of the wiring finds its way in to the blower.

Loosen the set screw before you try to slip the wheel on, once you get the shaft through you can hold it to get it aligned with the set screw(or the shaft may be cut too short to protrude and that is why it loosened).

EdTheHeaterMan

rsilvers

Yeah this will work. The small tube has slack at the ceiling hangers so I can move it. The large tube can push enough.

STEVEusaPA

rsilvers said:

You guys helped a lot because you showed me it can come out. I removed the electrical panel, which was a bit of a pain as the installer thought it would be a good idea to bolt the power cutoff switch over the screws that hold in the controller section. I disconnected the wires after labelling them all.

But now my problem is that I cannot slide the blower out all of the way because numbnuts thought it would be a good idea to run the hydroponic and refrigerant lines straight up the front. In theory I can cut and patch the hydroponic line, and bend the refrigerant line out of the way. Of course I want to avoid doing that.

I found the motor shaft, and I am having a hard time aligning the hamster wheel onto it. I assume I have to get it up and pushed into the motor, and aligned on some kind of indexing feature. But that is hard to do because I cannot grab the motor shaft to keep it from rotating with the blower wheel.

Welcome to our world of following/servicing sh!t installs.

rsilvers

Thanks for the tip to bend the copper. That worked. I got the blower out. Part of the issue was the motor was not positioned on the mount with the proper offset. I had to shift it at least 1/2 an inch so that it was centered in the housing.

A few more issues. What is this piece that I found sitting inside the blower housing?

Also, when I tighten the square-head bolt, it tilts the fan on the shaft. See video:

https://www.youtube.com/shorts/HAfP7hXvT_8

The shaft is not bent - it is just that the blower is a fairly loose fit to the shaft such that making the bolt tight cants the hamster wheel. Am I supposed to make a shim from 0.010 to 0.020" brass strip?

rsilvers

Should I get this to find the thickest shim I can grease and slide in?

ratio

That loose piece is the other part of the shaft. The wheel spun on there long enough to grind it down until it snapped off.

You need a new motor. A universal should be fine.

rsilvers

WOW!

rsilvers

The mount expects 5.6" in diameter.

HVACNUT

That's been  happening for a while. Looks like lathe work.
You've got numbers on the motor and fan to order new.

rsilvers

I am thinking of an ECM motor since this is for my house and electric here is 4x the national average. They claim to be 80% efficient. Anyone know the efficiency of the non-ECM motors?



https://www.supplyhouse.com/US-Motors-5642-RESCUE-EZ13-OAO-ECM-Direct-Drive-Blower-Motor-115-208-230V-3-4-HP-1075-RPM

https://www.supplyhouse.com/US-Motors-6643-1-Phase-Select-Pro-Programmable-ECM-Blower-Motor-48Y-115-208-230V-3-4-HP-1075-RPM

rsilvers

I wonder if the poor fit is the motor shaft being worn more narrow, or the fan hole being made wider, or both?

I don't know how to get this fan out of the housing. Would I want a fully new fan with new housing?

HVACNUT

rsilvers said:

I wonder if the poor fit is the motor shaft being worn more narrow, or the fan hole being made wider, or both? I don't know how to get this fan out of the housing. Would I want a fully new fan with new housing?

You'll need a wheel puller or a new housing. You're choice. 

rsilvers

The puller is to get the fan off the motor shaft but it is already loose. How can one take the fan out of the housing? The housing seems welded shut.

rsilvers

Has anyone here put a current meter on a 3/4 HP ECM motor and a 3/4 PSC motor in the same system? I wonder how many watts it saves.

JUGHNE

There is usually a door. A curved section of the housing about 5-6" long held in place by screws. With that and the motor removed the wheel should roll out of the housing.

I can't believe that didn't make some grinding sound to produce that cone shaped shaft.

The hub of the wheel is probably ground out and is why you should replace it also.

Note: you are lucky to still have the paper sticker on the wheel with numbers,
You can get a universal replacement wheel.
Match the diameter and width...also rotation.

rsilvers

This study shows about 30% saved:

https://www.nrel.gov/docs/fy14osti/60760.pdf

rsilvers

The blower says: 12-9 0.5 CLW CV

I measured it and it is 9 inches wide on the blades. 9.5 inches wide overall. 12 inches in diameter.

I think CLW means clockwise in 1999 lingo.

I think CV means convex.

The shaft is 1/2 inch.


This might be an example of one: : https://www.marsdelivers.com/item/41364/12-9-DD-0-50-CW-CV-WHEEL/

Can find it locally for $220. No one seems to have them in stock online.

rsilvers

This might work. I think it is convex: https://www.supplyhouse.com/Lennox-86H46-12-x-9-CW-Blower-Wheel-w-1-2-Bore

mattmia2

supplyhouse.com has a lot of stuff that is shown as out of stock that they get quickly from the distributor if you order it. look at a lau catalog and find what part number you're looking for

HVACNUT

If the shaft moves freely in the hub, remove the 3 or 4 motor mount bolts from the housing and pull the motor out.
Then there's a shield inside the housing. Remove 2 screws, remove the shield, and pull out the fan.

SuperTech

I wouldn't bother with the ECM motor. Just get a universal replacement PSC motor and call it a day. 

mattmia2

i looked at ecm motors when i replaced the motor in my furnace. I think i figured paying 3x the price was something i would never recover in savings.

rsilvers

mattmia2 said:

i looked at ecm motors when i replaced the motor in my furnace. I think i figured paying 3x the price was something i would never recover in savings.

Here is my research since when I asked:

A PSC motor is $169. An ECM is $269. So $100 more. We live in a blue state, meaning, they blocked the natural gas pipeline and they bring in fuel only by ship. So, we pay 0.45kWh for electricity.

An ECM will use 200-300 watts less power, and for my system, it is used for AC and heat.

So assuming it runs for 5 hours a day, that is about 50 cents per day, or about $300 a year more electricity. The difference will pay off within the first year.

I ordered the ECM motor and a new wheel.

mattmia2

Trying to fix the parts unless you have a lathe and can make parts is likely to leave you with a failure at an inconvenient time. The bore in the blower would need to be enlarged and a sleeve pressed in and you would need to move the motor so it can clamp on an undamaged section of shaft.

I'm not seeing hundreds of watts in difference between motors but the way motors are rated is a bit dubious, it is sort of like we have these parts we use for many motors, let's test them under this very specific condition and publish a rating that doesn't reflect the real world conditions.