ARMY TM 9-6115-645-24
AIR FORCE TO 35C2-3-444-12
MARINE CORPS TM 09244A/09245A-24/2
1-12.1.3.1 Coolant High Temperature Switch. This device will activate when the engine coolant leaving the engine ex-
ceeds 225 ± 5°F(107 ± 30°C).
1-12.1.3.2 Low Oil Pressure Switch. This device activates when the engine lubrication oil pressure falls below 15 ± 3
psi (103.4 ± 20.7 kPa).
1-12.1.3.3 Low Fuel Level Float Switch. This device will activate when the fuel level falls to a point at which the operating
time of the set at rated load is four minutes.
1-12.1.3.4 Overvoltage Relay. This device will activate when the 120-volt generator coil winding has risen to and re-
mained at any value greater than 153 ± 3 volts.
1-12.1.3.5 Overspeed Relay. This device will activate when the engine speed exceeds 2200 ± 40 RPM.
1-12.1.4 Fuel Float Switch Module. This device prevents inadvertent engine shutdown by providing a one second delay
after actuation of the low fuel level float switch.
1-12.1.5 Electrical protection devices will cause two events to occur. The AC circuit interrupter relay will open, and a
fault indicator lamp will illuminate which fault occurred.
1-12.1.5.1 Short Circuit Relay. This device will activate when the set output current in any phase exceeds 425 percent
of the rated value.
1-12.1.5.2 Overload Relay. This device will operate when the load current in any phase exceeds 110 percent of rated
value.
1-12.1.5.3 Undervoltage Relay. This device will activate instantaneously when the 120 volt generator coil winding has
dropped to 48 volts and will trip after time delay when the coil voltage drops below 99 volts.
1-12.1.5.4 Reverse Power Relay. This device will operate if power flow into the generator set exceeds 20 percent of
rated value.
1-12.1.6 Although it is possible for more than one fault to occur at one time during operation, only the first fault to occur
will be displayed by the malfunction indicator. The activated indicator lamp circuit remains illuminated until the malfunction
indicator is reset. The lamp will be off with the MASTER SWITCH in the OFF position and will be reilluminated when the
MASTER SWITCH is turned to one of the RUN positions. Resetting a fault indication is done in two steps. First push the
PUSH TEST & RESET LAMPS switch located on the malfunction indicator. Then move the MASTER SWITCH to the OFF
position. After the shutdown due to engine overspeed, the OVERSPEED RESET switch must be actuated to reset the
engine electrical control circuit before the engine can be restarted.
1-12.1.7 After the generator set engine has been started, the BATTLE SHORT switch can be used to override all of the
potential faults except engine overspeed and short circuit.
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