Grizzly Vertical Milling Machines G0728 - Manual (Page 36)

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Models G0728–31 (Mfg. Since 11/11)
SECTION 7: SERVICE
Troubleshooting
Motor & Electrical
symptom possible Cause possible solution
Machine does not
start or a breaker
trips. 1. spindle direction switch is at fault.
2. plug/receptacle is at fault or wired
incorrectly.
3. power supply is switched OFF or is at fault.
4. Motor connection wired incorrectly.
5. Motor windings or motor is at fault.
1. replace faulty spindle direction switch.
2. test for good contacts; correct the wiring.
3. Ensure hot lines have correct voltage on all legs
and main power supply is switched ON.
4. Correct motor wiring connections ( page 38).
5. replace motor.
Machine stalls or is
overloaded. 1. Machine is undersized for the task.
2. Motor connection is wired incorrectly.
3. plug/receptacle is at fault.
4. pulley/sprocket slipping on shaft.
5. Motor bearings are at fault.
6. Motor has overheated.
7. Motor is at fault.
1. use smaller sharp tooling; reduce the feed rate;
reduce the spindle rpM; use coolant.
2. Correct motor wiring connections ( page 38).
3. test for good contacts; correct the wiring.
4. replace loose pulley/shaft.
5. test by rotating shaft; rotational grinding/loose shaft
requires bearing replacement.
6. Clean off motor, let cool, and reduce workload.
7. test and repair or replace.
Machine has
vibration or noisy
operation. 1. tool holder or cutter is at fault.
2. Motor or component is loose.
3. pulley is loose.
4. Machine is incorrectly mounted or sits
unevenly.
5. Motor fan is rubbing on fan cover.
6. Motor bearings are at fault.
1. replace out-of-round tool holder; replace/resharpen
cutter; use appropriate feed rate and cutting rpM.
2. inspect/replace stripped or damaged bolts/nuts, and
re-tighten with thread locking fluid.
3. realign/replace shaft, pulley, setscrew, and key as
required.
4. tighten/replace mounting bolts in floor; relocate/
shim machine.
5. replace dented fan cover or fan.
6. test by rotating shaft; rotational grinding/loose shaft
requires bearing replacement.
Review the troubleshooting and procedures in this section if a problem develops with your machine. If you
need replacement parts or additional help with a procedure, call our Technical Support at (570) 546-9663.
Note: Please gather the serial number and manufacture date of your machine before calling.