Grizzly G7948 - Service and Troubleshooting; Motor and Electrical Troubleshooting

Model G7947/G7948 (Mfd. Since 01/21)
-39-
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.
SECTION 7: SERVICE
Troubleshooting
Symptom Possible Cause Possible Solution
Machine does not
start or a breaker
trips.
1. Switch disabling key removed or at fault.
2. Incorrect power supply voltage or circuit
size.
3. Power supply circuit breaker tripped or fuse
blown.
4. Motor wires connected incorrectly.
5. Wiring open/has high resistance.
6. Start capacitor at fault.
7. Centrifugal switch at fault.
8. Motor at fault.
1. Insert disabling key or replace.
2. Ensure correct power supply voltage and circuit
size.
3. Ensure circuit is sized correctly and free of shorts.
Reset circuit breaker or replace fuse.
4. Correct motor wiring connections (Page 43).
5. Check/fix broken, disconnected, or corroded wires.
6. Test/replace.
7. Adjust/replace centrifugal switch if available.
8. Test/repair/replace.
Machine stalls or is
underpowered.
1. Incorrect/dull cutter/bit for task.
2. Feed rate/cutting speed too fast.
3. Belt(s) slipping.
4. Machine undersized for task.
5. Motor overheated.
6. Pulley slipping on shaft.
7. Centrifugal switch at fault.
8. Motor at fault.
1. Use correct cutter/bit.
2. Decrease feed rate/cutting speed (Page 29).
3. Ensure belts are oil free, tension/replace belt(s);
ensure pulleys are aligned.
4. Perform operation with different machine.
5. Clean motor, let cool, and reduce workload.
6. Tighten loose pulley; replace broken/missing parts.
7. Adjust/replace centrifugal switch if available.
8. Test/repair/replace.
Machine has
vibration or noisy
operation.
1. Motor or other drive component loose.
2. V-belt(s) worn or loose.
3. Motor fan rubbing on fan cover.
4. Pulley loose.
5. Motor mount loose/broken.
6. Motor or spindle bearings at fault.
7. Chuck unbalanced or cutter dull.
1. Inspect/replace damaged bolts/nuts, and retighten
with thread locking fluid, if necessary.
2. Inspect/replace belts with a new matched set
(Page 29).
3. Fix/replace fan cover; replace loose/damaged fan.
4. Re-align/replace shaft, pulley set screw, and key.
5. Tighten/replace.
6. Test by rotating shaft; rotational grinding/loose
shaft requires bearing replacement.
7. Replace chuck; replace/resharpen cutter.
Motor & Electrical