Part II of Motor Maintenance

To complement the article last month on Meg-Ohm testing your motors annually, here are some additional tips to keep your motors humming. 

The need to keep expensive motors from failing is important to your employer or customer. Budgets are lean and when motors prematurely fail for reasons that could have been prevented, or fail resulting in emergency or after-hours response, budgets get hit. Sometimes very hard. 

Here are some suggestions to maximize expected motor life...

1. Keep it clean. Clean air filters of a descent quality also help to keep the motor windings clean. Make sure no unfiltered air can leak or enter between the air filters and blower section. A buildup of dirt and lint act as an insulator and create "hot spots" where the most buildup occurs. The motor insulation at these hot spots are the likely areas where a failure will occur due to localized excessive heat. Vacuum or blow it out.
2. Clean the motor and/or blower wheel if dirt buildup occurs. With that said, I must point out the obvious here. You must clean the wheel thoughly and uniformly. The wheel was balanced when it was new. Leaving a bit of dirt on part of the wheel causes an unbalance which will damage the motor bearings. If the wheel won't balance, replace it. 
3. Check motor bearings which should operate free and smooth. Test amp draw (under normal load with doors closed) and compare to nomenclature on the motor itself, not the unit template.
4. Ensure the duct design is adequate for the motor/blower to perform the needed work. Restrictions in ducting will cause a PSC motor to draw lower amps as it is moving less air. ECM motors will speed up to try to compensate for poor duct design and draw more current. More current = more motor heat.
5. Clean the evaporator coil if dirty.
6. Check the motors run capacitor. Replace if bulged out on top. Your capacitor analyzer should show you within about 5% of the rating of the capacitor.
7. Lubricate if it's an older motor than needs oil. Grease motor bearings on larger motors, but don't over grease. 
8. Verify electrical connections are tight.
9. Verify the motor and blower mounting are secure and tight, minimizing any movement.
10. On large motors operating with VFD's, buy a shaft grounding kit such as an Aegis brand kit to protect bearings from damage by induced shaft electrical transmission.

You may know of one or two other tips. Please comment below if wish to share with us!