BUSHING 8N8258 - Caterpillar

Fault Shutdown Output Driver
The fault shutdown driver is intended to provide an external signal to operate a circuit breaker shunt trip and other alarm lights and/or horns in the event of a shutdown fault. The fault shutdown driver is normally pulled low (sinking up to 100 mA). When a fault occurs the output driver will open, allowing the output to go high, to +24 VDC.Note: The output driver is "pull down" only. It will not source current when a fault occurs. Use input terminal 50 for a current source. Refer to the Customer Options illustration in Testing And Adjusting, "Wiring Diagrams".This method was chosen as a safety feature to protect against loss of battery voltage which will also cause the regulator to cease operation and, therefore, the generator voltage to collapse.Alarm Output Driver
The alarm driver is intended to provide an external signal to operate alarm lights and/or horns in the event of an alarm fault condition. The alarm driver is normally pulled low (sinking up to 100 mA). When an alarm occurs, the output driver will open, allowing the output to go high, to +24 VDC.Note: The output driver is "pull down" only. It will not source current when a fault occurs. Use input terminal 50 for a current source. Refer to the Customer Options illustration in Testing And Adjusting, "Wiring Diagrams".Note: The alarm output and fault shutdown output drivers may change state during engine cranking, indicating a false alarm or shutdown fault condition. If the "B+"/"B-" inputs to the digital voltage regulator are supplied from the engine cranking batteries, it is likely that insufficient voltage will be present during cranking. Therefore, during cranking the state of the fault shutdown output driver may change. The fault shutdown output driver should be ignored until the crank terminate speed has been reached.Excitation Disable
The excitation disable switch is intended to provide a method of disabling the regulator field output (F1 and F2) in a manner which is safe for the regulator internal components. This feature is activated by shorting terminal 42 to terminal 50. Refer to the Customer Options illustration in Testing And Adjusting, "Wiring Diagrams". Activation of the excitation disable switch will also disable the undervoltage shutdown fault.
The generator will always have residual voltage still remaining; therefore, it is important to stop the generator set if downstream maintenance is to be performed.
Fault Reset
The fault reset contact is provided as a method to reset a resettable shutdown fault through the use of an external switch. This operation is equivalent to using parameter :96 in the user interface. Operating the fault reset contact (momentarily shorting terminal 43 to terminal 50) will reset a resettable fault and allow the voltage to build again. However, on the "original" fault handling versions, the display will still show the flashing fault and the fault will remain in the active position in memory. On the "new" fault handling versions, the display will stop flashing, return to showing ":01", and the fault will remain in the active fault