Step-by-step tips for your customers’ motor issues
2 MIN READ
For some service technicians, motor repair really means motor replacement. After all, if you don’t know how to fix a broken motor, changing a malfunctioning unit may be your only option.
For others, repairing the small electric motors that power pool and spa pumps is a useful way to keep down the cost for the customer while earning a tidy profit.
When it comes to motor service, Elias Duran is an acknowledged expert. When he finishes his weekly service route, his attention often turns to motor repair — and he’s been teaching the basics of motor teardown and repair for more than a decade.
The owner of Duran’s Pool & Spa Service in North Hills, Calif., offers some pointers for technicians to keep in mind as they approach ailing motors:
Always use quality replacement parts, as recommended by the motor manufacturer. When tearing down a motor or replacing parts, never force anything — or you may end up replacing additional parts.
If you need help with a motor, take it to a reputable motor-repair shop.
Be safety-conscious when working with electricity. Always be sure the motor is grounded before connecting the power. Another must: The power source needs to be disconnected before you begin working on the motor. Also be sure you are using the correct electric voltage.
Remember that some slight differences may occur between different motor models. When in doubt, consult the manufacturer’s handbook for the specific model you’re repairing. In the accompanying pictorial, Duran offers instructions on how to tear down and reassemble a motor. He also provides detailed troubleshooting tips and instruction on how to replace ball bearings, perhaps the most common form of motor repair.
Tools for the job
Flat-head screwdriver Small mallet Socket wrench or nut driver (1/4- to 5/16-inch, as needed) Bearing puller Bearing drivers (two sizes) Ohmmeter Plumber’s sand cloth or emery paper Red insulating varnish spray (for windings) Spray paint (for motor housing) Masking tape Marking pen
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1. Remove the terminal connection coverLoosen the terminal conne…
1. Remove the terminal connection coverLoosen the terminal connection cover’s two screws with a flat-head screwdriver and remove the terminal connection cover. Check connections on terminal board. Test the electrical-line leads with an ammeter/voltmeter while supplying electric power; disconnect power before proceeding.
2. Mark the end-bell/stator alignmentUsing a marking pen or mask…
2. Mark the end-bell/stator alignmentUsing a marking pen or masking tape, mark the position of both end bells for proper alignment with the stator.
3. Remove through boltsRemove the four through bolts using the a…
3. Remove through boltsRemove the four through bolts using the appropriately sized socket wrench or nut driver; bolt heads will vary from 1/4- to 5/16-inches.
10. Remove the ball bearingsUsing a bearing puller, remove the l…
10. Remove the ball bearingsUsing a bearing puller, remove the lock collar, ball bearing and backing plate from the shaft end — and the smaller ball bearing from the opposite-shaft end.
11. Replace the front bearings: Reinstall the backing plate on t…
11. Replace the front bearings: Reinstall the backing plate on the shaft end. Install the new bearing. The bearing should only be put on with a bearing press or using a pipe or collar piece the same diameter of the inner race (the steel ring of the bearing that makes contact with the motor shaft), tapped lightly by a mallet until seated against the appropriate shaft shoulder or stop. Force should be applied only to this inner race to avoid damaging the bearing.
12. Replace the rear bearings: Refer to the procedure described …
12. Replace the rear bearings: Refer to the procedure described in Step 11, excluding the backing plate.
13. Replace the shaft-end bell: Slide the shaft-end bell onto th…
13. Replace the shaft-end bell: Slide the shaft-end bell onto the shaft; tap the end bell with a mallet if necessary. Hint: Thread two appropriately sized through bolts into the locking plate to use as guides when replacing the locking ring screws. (Bolts can be salvaged from an old motor.)
14. Replace the locking ring screws: Replace the two locking rin…
14. Replace the locking ring screws: Replace the two locking ring screws in the shaft-end bell. If you use the hint from Step 13, leave one “guide” through bolt in place while you replace the other; then replace the second screw. Tighten the two screws.
15. Reinstall the end bell: Slide the shaft-end bell back into t…
15. Reinstall the end bell: Slide the shaft-end bell back into the motor for reassembly. Be sure to match the alignment marks on the end bell and stator. Tap the end bell lightly with a mallet if necessary.
16. Replace the REAR-end bell: Slip the rear-end bell back into …
16. Replace the REAR-end bell: Slip the rear-end bell back into place after replacing the bearing spring. Be careful not to pinch any wires between parts, and match the alignment marks on the end bell and the stator. Tap the end bell lightly with the mallet if needed.
17. Replace the through bolts: Replace the four through bolts an…
17. Replace the through bolts: Replace the four through bolts and tighten them as you would tighten the lug nuts on a car wheel — that is, a little at a time while rotating from one to another until they are all tight.
20. Replace the terminal connection cover: Replace the terminal …
20. Replace the terminal connection cover: Replace the terminal connection cover and tighten the two bolts.
An invaluable skill for any service technician, motor tear down and reassembly are needed for most repairs. Follow the steps in this slideshow for tear-down, bearing replacement and reassembly.
The last step
You’ve finished the motor reassembly, but before reinstalling the unit, Elias Duran, owner of Duran’s Pool & Spa Service in North Hills, Calif., suggests taking one more step: If the motor’s cover is scratched, rusted or faded, give it a new coat of paint.
First clean the motor cover, then mask the nameplate and other important labels on the face of the motor with tape. (It’s crucial to protect the nameplate before painting because it bears information critical for future troubleshooting or motor replacement.)
Now apply a light coat of spray paint to give the motor a clean, rejuvenated appearance.
A final hint from Duran: Use the original paint color — or, if your customer prefers, use a color that matches the other equipment on the pad.
