ARMY TM 9-6115-641-24
AIR FORCE TO 35C2-3-456-12
1-12-1-3. Activation of anyone of the following protection devices will cause three evants to occur. The AC circuit inter-
rupter relay holding circuit will be deenergized causing the AC circuit interrupter relay to open; the generator set engine
will be shutdown; and a fault indicator lamp will be illuminated to show which malfunction occurred.
1-12-1-3-1. Coolant High Temperature Switch. This device will activate when the engine coolant leaving the engine
exceeds 225 ± 5°F (107 ± 3°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 Ievel falls to a point at which the operat-
ing time of the set at rated Ioad 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.
1-12-1-4. 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. Activation of any of the following electrical protection devices will cause two events to occur. The AC circuit
interrupter relay will open and a fault indicator lamp will illuminate to indicate which fault occurred.
1-12-1-5-1. Short Circuit Relay. This device will activate when the set output current in any phase exceeds 425X 25
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.
1-12-1-6. 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 re-illuminated 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. The generator set cannot be cranked unless both actions are completed. The indicated fault must be corrected
before any attempt is made to restart the generator set or dose the AC circuit interrupter relay.
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