JOLIET Guaranteed AC Motor Refurbishing Checklist of Procedures
This precise checklist of procedures ensures that our JOLIET Guaranteed line of rebuilt motors is of the highest quality and provides the best performance possible. All work is performed according to ISO 9001 quality standards.

1. As necessary, the motor's exterior is treated with an abrasive blast making sure all other surfaces, including the nameplate, are protected from damage.
   
   
2. Megger ohmmeter test is performed to measure and record electrical resistance according to IEEE Standard 43.
   
   
3. Shaft runout is checked and recorded.
   
   
4. Single-phase check is run to locate any broken rotor bars.
   
   
5. Voltage is applied to stator on all slip-ring motors and secondary voltage is checked.
   
   
6. With acceptable Megger readings, the motor is run at no load, current balance and vibration data are checked.
   
   
7. The motor is disassemblied, rotor bars are counted and recorded.
   
   
8. All bearings, seal and coupling fits are measured for proper tolerance. Those tolerances required for ball, roller and angular contact bearings are recommended by the AFBMA. Tolerances required for Babbitt-type bearings are provided by the OEM.
   
   
9. Any out-of-spec mechanical tolerances are repaired and final dimensions are recorded.
   
   
10. Surge comparison test is performed on motor windings, documenting all results.
    
    
11. All motor parts are cleaned, with a special steam cleaning process performed on the stator/winding followed by bake cycle.
    
    
12. Internal parts are painted with a unique insulating epoxy.
    
    
13. Once baking is completed. Megger test is repeated and results are recorded.

14. The motor is dipped with a Class F varnish and windings are baked a final time.
    
    
15. If new windings are required, data is evaluated for suitability to applications- including calculation of all flux densities and proper rotor bar/stator slot combination.
    
    
16. All coils in new form wound windings are manufactured according to Joliet specifications which include glass over film copper conductors and taped leads.
    
    
17. New form wound windings are Class F VPI processed using Joliet's Epox-E-Clad system documenting all critical process parameters.
    
    
18. Rotor is balanced to levels lower than those listed in the NEMA MG-1-1993 specifications.
    
    
19. New bearings are used if ball, roller or thrust is required. (If original Babbitt- type bearing requires repairs, the spin cast process is used to yeild maximum bonding.) All Babbitt-type bearings meet OEM tolerance levels.
    
    
20. A high-potential test is then performed on the completed, assembled motor according to IEEE Standard (%.
    
    
21. The motor is run at rated voltage and frequency until bearing temperatures stabilize.
    
    
22. Bearing temperatures, no-load volts, amps and rpms are recorded.
    
    
23. Vibration analysis is performed using IRD 890 equipment at all frequencies to establish a baseline, documenting all results.
    
    
24. Shaft nut or key is furnished.
    
    
25. Motor is painted and placed on skid for shipment, sleeve bearing motor shafts are blocked.

JOLIET Guaranteed DC Motor Refurbishing Checklist of Procedures Steps 1-13 (except 4 & 5) from the AC checklist are repeated for DC equipment.

1. AC drop test is performed on field coils.
   
   
2. High current test is performed on interpoles.
   
   
3. Armature and field frame are dipped and baked. If armature and/or field frame has been rewound, Class F VPI process is followed.
   
   
4. Commutator is turned and undercut.
   
   
5. Armature is dynamically balanced.
   
   
6. New brushes and bearings are installed.
   
   
7. Brush spacing is checked, set and neutral set.
   
   
8. A no-load test is performed to check bearing temperatures. Load test, as necessary, to check commutation.
   
   
9. Vibration data, speeds, currents and voltages are documented.