ARMY TM 9-6115-639-13 AIR FORCE TO 35C2-3-386-51 MARINE CORPS TM 10155A-13/1 13 CIRCUIT INTERRUPTER Switch (S5) Two   position   switch   that   applies   generator voltage to the output load terminal board. CLOSED position signals AC circuit interrup- ter K1 to close, applying voltage to the terminal board. OPEN position opens AC circuit interrupter   K1, terminating current to the load. 14 CIRCUIT INTERRUPTER Indicator (DS6) Lights when CIRCUIT INTERRUPTER switch S5 is in CLOSED position, indicating load is being applied to the terminal board. 15 VOLTAGE ADJUST Rheostat (R1) Allows operator to adjust generator set output voltage. 16 START / RUN / STOP Switch (S1) Three-position switch that controls generator set operation. START position activates engine starter B1. Spring loaded.  Must be held in position. RUN position cuts electrical power to the starter.  Energizes all circuits required for normal operation. OFF position opens the circuit to engine fuel transfer pump E2 and governor control A5, stopping fuel flow to the engine and shutting down the generator set. 17 PREHEAT Switch (S18) Two-position switch that controls the engine preheat system. ON position sends a signal to engine preheat contactor K13 to energize the engine air   heater.  Used during cold weather operation. OFF position de-energizes the engine air heater, halting engine preheat operations. 18 AUX FUEL Switch (S17) Two-position switch that allows the generator set to operate using an auxiliary fuel source. ON position allows a three-position fuel level switch (FL, mounted in the generator set fuel tank) to regulate auxiliary fuel flow into the fuel tank.  See item 25 for details. OFF position de-energizes auxiliary fuel circuit, preventing auxiliary fuel pump E1 from operating. 19 EMERGENCY STOP Switch (S19) A push-button switch that opens AC circuit interrupter K1 and disconnects power to governor control A5, which causes generator set to shut down.  For emergencies only. 20 Engine Start Handle Allows for manual start of the generator set engine.  Activates engine’s recoil starter   assembly. 21 Fuel Drain Plug Allows personnel to drain generator set fuel tank.  Connected to a fuel drain line. 22 Engine Oil Drain Plug Allows personnel to drain engine oil sump.  Connected to an oil drain line. 23 Temperature Switch (S21) Monitors temperature inside the generator set enclosure.  Activates ventilation fan B3 when   temperature reaches 110F (43C). 24 Temperature Switch (S20) Monitors temperature inside the generator set enclosure.  Activates ventilation fan B2 when temperature reaches 85F (29C). 2-3