COVER-FINAL DRIVE-LH 8V7751 - Caterpillar

Circuit Breaker
The circuit breaker is a switch that opens the battery circuit if the current in the electrical system goes higher than the rating of the circuit breaker.A heat-activated metal disc with a contact point completes the electric circuit through the circuit breaker. If the current in the electrical system gets too high, the metal disc gets hot. This heat causes a distortion of the metal disc. The disc opens the contact in order to break the circuit.
Find and correct the problem that causes the circuit breaker to open. This will help prevent damage to the circuit components from too much current.
Speed Sensor
The speed sensor monitors engine rpm by sensing the movement of the flywheel ring gear's teeth.
Illustration 1 g00608052
Speed sensor
The speed sensor has wire that is coiled around a permanent magnet in order to generate a magnetic field. Voltage is produced as the teeth of the flywheel ring gear pass through the magnetic field. Positive voltage is generated when each gear tooth passes the magnet. Negative voltage is generated when the spaces between the teeth pass the magnet.Water Temperature Contactor Switch
Illustration 2 g00580098
Water temperature contactor switch
The element of the water temperature contactor switch is installed in the water temperature regulator housing. The switch is nonadjustable. Thermal expansion of the element operates a microswitch. The switch can be wired to an alarm system or a shutdown in order to help provide protection from high water temperature. The element must be in contact with the coolant. The contactor will automatically reset when the coolant temperature is reduced below the threshold.Air Temperature Contactor
Illustration 3 g00808031
Air temperature contactor
The air temperature contactor is installed in the inlet air manifold. The switch is nonadjustable. Thermal expansion of the element operates a microswitch. The switch can be wired to an alarm system or a shutdown. The element must be in contact with the inlet air. The contactor will automatically reset when the air temperature is reduced below the threshold.