Prevent Pinsetter Motor Failure

After months of no activity, pinsetter motors can have some major problems. The majority of these failures can be traced to the mechanical centrifugal switch. A single-phase AC motor has a centrifugal switch inside its case, attached to the motor shaft. The switch is closed when the motor is off and motionless. When you turn the motor on, the switch conducts electricity to a capacitor and an extra coil winding in the motor, increasing its starting torque. As the motor's revolutions per minute increase, the switch opens, as the motor no longer needs the boost.

If the centrifugal switch fails to open, the start windings in the motor will burn up. When this happens, the motor will not start. To do a quick check, remove the belts from the motor and turn it on. After a few seconds, you will probably hear a click. This is the switch opening, it does this when the motor reaches about 75% of its maximum rotations per minute. Turn the motor off. As the rotation slows, the switch will close. If you suspect the switch is sticking, you can send the motor out to be repaired or check the switch yourself. There are many videos online regarding this repair.