Section 7: Service; Troubleshooting - Grizzly G0779 Owner's Manual

SECTION 7: SERVICE

Review the troubleshooting 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. Note: Please gather the
serial number and manufacture date of your machine before calling.
Motor & Electrical
Symptom Possible Cause
Machine does not 1. Incorrect power supply voltage or incoming
start or a breaker
wire connections.
trips.
2. Power supply circuit breaker tripped or fuse
blown.
3. Motor wires connected incorrectly.
4. Wiring open/has high resistance.
5. Start capacitor at fault.
6. Spindle rotation switch at fault.
7. Centrifugal switch/contact points at fault.
8. Motor at fault.
Machine stalls or is 1. Machine undersized for task.
underpowered.
2. Wrong workpiece material (metal).
3. Motor overheated.
4. Motor wired incorrectly.
5. Plug/receptacle at fault.
6. Gearbox at fault.
7. Run capacitor at fault.
8. Centrifugal switch/contact points at fault.
9. Motor bearings at fault.
10. Spindle rotation switch at fault.
Machine has 1. Motor or component loose.
vibration or noisy
operation.
2. Chuck or cutter at fault.
3. Motor fan rubbing on fan cover.
4. Motor mount loose/broken.
5. Machine incorrectly mounted/secured to
floor.
6. Motor or spindle bearings at fault.
7. Centrifugal switch is at fault.
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Troubleshooting

Possible Solution
1. Ensure correct power supply voltage and incoming
wire connections.
2. Ensure circuit is sized correctly and free of shorts.
Reset circuit breaker or replace fuse.
3. Correct motor wiring connections.
4. Check/fix broken, disconnected, or corroded wires.
5. Test/replace.
6. Test/replace switch.
7. Adjust/replace centrifugal switch/contact points if
available.
8. Test/repair/replace.
1. Use correct cutter/bit; reduce feed rate; reduce
spindle RPM; use coolant if possible.
2. Use correct type/size of metal.
3. Clean motor, let cool, and reduce workload.
4. Wire motor correctly.
5. Test for good contacts/correct wiring.
6. Select appropriate gear ratio; replace broken or
slipping gears.
7. Test/repair/replace.
8. Adjust/replace centrifugal switch or contact plate.
9. Test/repair/replace.
10. Test/replace switch.
1. Inspect/replace damaged bolts/nuts, and retighten
with thread locking fluid.
2. Replace unbalanced chuck; replace/resharpen
cutter; use correct feed rate.
3. Fix/replace fan cover; replace loose/damaged fan.
4. Tighten/replace.
5. Tighten mounting bolts; relocate/shim machine.
6. Test by rotating shaft; rotational grinding/loose shaft
requires bearing replacement.
7. Replace.
Model G0779 (Mfd. Since 09/14)