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ALWAYS DISCONNECT MACHINE FROM POWER SOURCE BEFORE SERVICING
MACHINE IS HARD TO HANDLE
1. Change to a less aggressive plate.
2. Re-adjust plate angle.
3. Reduce wheel size.
MACHINE IS OVERLOADED
1. Let machine rest and cool down. Reset overload button on motor.
2. Check power cord. Use a 12 gauge cord, 50' or less.
DEBRIS IS COMING OUT FROM THE BOTTOM OF THE MACHINE
1. Check shroud to make sure it is mounted and secured properly. The shroud should suck down to the
floor when the vacuum is on. Make sure the plate does not protrude out from the shroud.
BLOWS FUSES OR CIRCUIT BREAKERS
1. Check and/or change attached power cord. Use a 12 gauge cord or heavier, 50' or less.
2. Move to a different outlet or a better circuit.
MOTOR WILL NOT RUN
1. Check for a blown fuse and/or circuit breaker at the electrical panel.
2. Overload switch has been tripped.
3. Defective handle switch.
4. Defective power cord.
NOISY OR EXCESSIVE VIBRATION
1. Defective motor. Contact National for service.
2. Bad belt or belt needs maintenance. Retighten or change the belt.
3. Plate or cup wheel is out of balance. Change plate or rebalance.
4. An incorrect adapter on the plate or or cup wheel. Change to a different adapter specified for the job
type.
5. Drive pulley is out of alignment.
TOO MUCH SHROUD SUCTION
1. Reduce vac size.
2. If using a twin motor vacuum, turn one motor off
3. Extend the vac hose length.
4. Add additional vent holes to the shroud.
MACHINE SPEED/TORQUE
1. Change the front pulley. See pulley change out.
TROUBLESHOOTING