ARMY TM 9-6115-604-12
NAVY NAVFAC P-8-633-12
MAINTENANCE OF AC CIRCUIT BREAKERS. These circuit provide an automatic safety disconnect of ac
power from their respective circuits.
Disconnect ac power
Tag and disconnect wiring to circuit breaker.
Remove screw and captive washer assembly, flat washer, and mounting bracket.
Remove circuit breaker.
Test. Test each circuit breaker using a MSIA circuit breaker tester
Position circuit breaker into mounting bracket.
Attach mounting bracket using screw and captive washer assembly, nut and captive washer
assembly, and flat washer.
Connect electrical wiring and discard tags.
Reconnect ac power
SECTION X. MAINTENANCE OF FUEL SYSTEM
GENERAL. See Figure 1-11 Fuel from an external source is supplied to the generator set fuel tank by a fuel
transfer pump. A solenoid valve prevents fuel from flowing through the fuel transfer pump when it Is not operating. A
fuel strainer Is located incline ahead of the fuel transfer pump, and two duplex fuel filter sets are arranged in parallel
between the fuel transfer pump and the generator set fuel tank. An engine driven fuel injection pump draws fuel from the
generator set fuel tank. A single duplex fuel filter set is located between the generator set fuel tank and the fuel injection
pump. A magnetic pickup mounted in the engine flywheel housing sends a signal to the electronic speed control located
inside panel B in the generator set control room. The electronic speed control governs the operation of an actuator
mounted on the fuel pump. The actuator regulates the pressure of the fuel supplied to the fuel injectors, thereby
regulating engine speed and horsepower. Fuel leaving the fuel injection pump flows into the fuel manifolds and then to
the fuel injectors located in each cylinder head.
When disconnecting fuel hoses, ensure that a suitable container is provided to
caps ture fuel runoff from the hoses. If it is necessary to close the manual fuel
shutoff valve, pull the push/pull emergency control on the exterior of the
generator set. Push the push/pull emergency control in to restore fuel flow.
MAINTENANCE OF FUEL TRANSFER PUMP . The fuel transfer pump is used to transfer fuel from an external
fuel source to the generator set fuel tank.
The following test should not be performed if the generator set fuel tank is more than
half full. Performing this test when the generator set fuel tank is more than half full may
provide inaccurate results due to fuel level sensor FL2 sensing sufficient fuel in the
generator set fuel tank and deenergizing the fuel transfer pump automatically. If it
becomes necessary, fuel must first be drained from the generator set fuel tank.
Ensure that the generator set is properly configured for utility ac power, and that an external fuel
source is connected to the generator set.
Turn FUEL PUMP switch S8 to OFF.
Open fuel tank drain valve and completely drain fuel into suitable container. Close drain valve.