Month: October 2020

I’ve seen a lot of guys recently who reach for the motor puller tool first thing when attempting to remove a blower motor from a wheel/fan blade. Motor puller tools are an awesome backup tool when needed, but that shouldn’t be the go-to method of removing a motor.

 

The main issue with using a motor puller for every single motor is its tendency to bulge out the shaft. Motor pullers work by clamping down on a hub and then twisting a small shaft against the motor shaft in order to push/pull the motor/wheel away from each other. Sometimes, when technicians don’t sand down a shaft and spray the area with WD-40 or other water displacement lubricants, the shaft will get stuck and a tremendous amount of force is required to crank the motor puller shaft against the shaft of the motor. These opposing forces can significantly bulge the motor shaft. If the technician is successful in removing the motor that way, they often find it more difficult to get the motor shaft back inside the bore of the wheel. 

My hope is every technician reading this understands that the cardinal rule of removing a motor is to never use any of the following methods:

  • Use a hammer/wrench/blunt object to beat the shaft out of the assembly
  • Use channel locks of set screws
  • Use channel locks on the motor shaft
  • Over tighten the set screw

Any of the above-mentioned sins can result in expensive problems.

Please note the two things that must be completed before using a motor puller: sanding the shaft and lubrication. Guess what…

 

That’s all you need to do to remove a shaft!

  1. Sand the motor shaft until shiny and smooth.
  2. Spray with water displacement lubricant
  3. Loosen the set screw (but don’t remove it. They are easy to lose)
  4. (Optional) Take an adjustable wrench and gently turn the shaft independently of the wheel
  5. (Optional) Slightly push the wheel down the shaft to sand the portion of the shaft that was previously unreachable, which may have a lip that needs to be sanded down.
  6. Gravity is your friend. Let the motor fall out of the assembly. A shake or two may be required.

 

Voila! Those are steps a technician needs to do before using a motor puller, yet 90% of the time, those steps are all that’s needed to do the job. 

 

One extra tip…Blow off the sandpaper/rust debris before applying the lubricant, and don’t apply lubricant before you sand the shaft. The debris can get stuck and make things even more difficult, and sandpaper that is saturated in WD-40 doesn’t do much good.

 

For a video on this method, we shared a post by Brad Hicks earlier this year of him demonstrating how it’s done!

The Surefire Way to Get a Blower Wheel Off

 

– Kaleb


When I started in the trade in 1999 there were still a lot of oilable blower motors in service. As part of the maintenance, we would remove the housing, oil the motor plus vacuum / wipe it down.

As oilable motors have become extinct I see fewer and fewer techs pulling the blower housing. Here are some reasons you may want to consider doing it more often.

  • Cleaning the motor itself can help it run cooler and last longer. A hot motor not only is more susceptible to winding breakdown but also to bearing/lubricant failure. Grab a vacuum, soft bristle brush, and a rag and get the dust buildup off the motor. If you have any dust that gets stuck inside, use some low-pressure nitrogen or compressed air to get it clean.
  • Get in there and look carefully at the wheel. A wheel that is even slightly dirty can have a significant effect on air output. If it’s dirty,  recommend cleaning.
  • Check the blower bearings, it’s easier to do when it’s out
  • On high-efficiency furnaces pulling the blower is a good way to check the secondary heat exchanger. On 80% furnaces, you can check parts of the primary exchanger and even the evaporator coil with a mirror or inspection scope.
  • Pulling the blower gives you the ability to wipe down the inside of the furnace or Fan coil.
  • You can check blower mounting bolts and set screws as well as blower alignment and balance more easily.

Obviously, when and why you pull the housing will vary from contractor to contractor but I advocate it being done more often than it is now.

What say you?

— Bryan

Trevor Matthews from Emerson Canada joins us again to talk about CoreSense by Emerson

 

Refrigeration Software (CoreSense Protection, Diagnostics & Performance Alert) – https://climate.emerson.com/OPI/documents/clc/CoreSense_PC_Communication_Software.exe

 

Air Conditioning Software (CoreSense Communications) – https://climate.emerson.com/OPI/documents/clc/CoreSense_PC_Communication_Software_AC.exe

 

HVACR Fault Finder App:

(Android) – https://play.google.com/store/apps/details?id=Emerson.FaultFinder&hl=en_US

(Apple) – https://apps.apple.com/ph/app/hvacr-fault-finder/id465325739

 

If you have an iPhone subscribe to the podcast HERE and if you have an Android phone subscribe HERE.

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