Motor physical inspection. (cleanliness, fan guard, frame, mounting bolt tightness, conduit condition).
Pecker head and its internal components inspection (for corrosion, loose connections, fraying).
Check motor fan cowl and cooling fans
Runtime bearing test (vibration, temp check,)
Lube (grease if it has the fittings for it. 1 to 2 shots for small motor.3 to 4 shots for larger motor).
Shaft Inspection (check for wear, position, key stock)
Coupling inspection (Check setscrews for tightness, coupling for wear and positioning).
Surroundings check. (ensure equipment is clear free of obstructions and hazards).
Complete standard short to ground check. check each wire, including T1, T2, T3 and the ground wire. If the reading is infinite, your motor should be fine.
Conduct standard Ohm check. Test T1 to T2, T2 to T3, and T1 to T3.
Complete standard leg Voltage test. Test the incoming voltage, place one of the multimeter's probes on L1 and the other on L2. Allow the multimeter to display the voltage and then repeat the tests while probing L1 and L3, then L2 and L3.
Conduct standard continuity test. Earth continuity and resistance test: Using a multimeter, measure the resistance between the body of the motor and the ground. You are looking for a reading of 0.5 ohms or less. Some standards may specify 0.1 ohms.
Complete Running Amps Test. With the motor running, check the full load amps (FLA) with a suitable meter or preferably a clamp on meter and compare with the name plate FLA. Deviations from rated FLA could signify problems with the motor under test.
Inspect disconnect (for damage, corrosion inside, etc.)
Source: MaintainX (Community Member)