ARMY TM 9-6115-670-14&P
1-4
Injection nozzle
Nozzle which injects fuel into engine until combustion takes place
Overload Relay
Safety device that opens the contactor in conditions of high current or
low voltage
Relay Board
Device that routes electrical signals within the APU
Rotor
The part of the generator that rotates within the stator
Starter
Device used to turn over an engine until it starts (combustion takes
place)
Stator
The part of the generator that remains stationary
Thermostat
Device used to regulate engine coolant temperature by controlling
coolant flow
Voltage rectification
Conversion of AC voltage to DC voltage
Section II. EQUIPMENT DESCRIPTION
1.11. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES.
1.11.1. Characteristics. The APU is a diesel engine driven, slide frame mounted, 10 kW, 60 Hz, single
phase, 3-wire 120/240 VAC unit which is used to supply electrical power for mission equipment mounted
in SICPS or JTACS shelters. It is installed in the SICPS or JTACS tunnel. The SICPS is normally
mounted on a HMMWV while the JTACS is mounted on a HHMMWV. In both shelters, the APU utilizes
the vehicle's fuel tank and batteries to reduce its weight.
1.11.2. Capabilities. The APU will start and run continuously, delivering a rated load of 10 kW at 0.8
power factor (PF) lagging, in all temperatures for -25°F to +125°F (-31.7°C to 51.6°C) at sea level. It will
provide a minimum of 10 kW at an altitude of 5000 feet (1524 meters) and a temperature of +107°F
(41.6°C). It will provide a minimum of 10 kW at an altitude of 8000 feet (2438.4 meters) and a
temperature of +95°F (35°C).
1.11.3. Features. The APU is a light weight (495 pounds (225 kg) (SICPS; WIN-T); 461 pounds (172
kg) (JTACS)) unit consisting of a 3600 rpm, turbo charged, liquid cooled, diesel engine coupled directly
to a two pole, 10 kW, 0.8 PF, 60 Hz generator, with excitation system (voltage regulator included);
starter; controls; 28 volt battery-charging system (alternator); electric governor; aluminum frame; shock
and vibration isolators, and mounting provisions to interface with the SICPS, JTACS or WIN-T. The
APU can be operated with the vehicle moving or stationary.
1.12. DIFFERENCES BETWEEN MODELS.
Table 1-1 details equipment differences between models MEP-903A (SICPS configuration), MEP-903B
(JTACS configuration), and MEP903C (WIN-T configuration).
