DESCRIPTION

ARMY TM 9-6115-464-12 AIR FORCE TO 35C2-3-445-1 NAVY NAVFAC P-8-624-12 b. c. d. e. f. Engine. Power source of the generator set is a four cylinder, four cycle, fuel injected, Iiquid-cooled diesel en- gine. The engine electrical system contains a cranking motor, two 12-volt batteries in series, and a battery charging alternator with integral rectifier and voltage regulator. The engine is also equipped with a fuel filter and strainer assembly, a secondary fuel filter, a lubricating oil filter, and an air cleaner. Cooling water is circu- lated through the engine by a water pump. Safety devices automatically stop the engine during conditions of high coolant temperature, low oil pressure, no fuel, over-speed, or over-voltage. Generators. The alternating current generators are single bearing, drip-proof, synchronous, brushless, three phase, fan cooled generators. Rated voltages are maintained by excitation of the generator-exciter field by a static exciter mounted on the relay table. The cooling fan, located at the front of the generator, impels cooling air which enters the generator and passes over the windings. Safety devices are provided to protect the generator in the event of short circuit, overload, under-voltage, under-frequency, reverse power, and over-voltage. Control Cubicle. The generator set control cubicle is located at the rear top of the generator set and contains controls and instruments for operating the engine and the generator. The control panel is grounded to pro- tect the operator from electrical shock in the event of a short in the equipment. The generator section of the control panel contains meters for monitoring generator output, adjusting knobs for increasing and de- creasing frequency (Class 1 only) and voltage, and a circuit breaker switch for interrupting all output from the generator set. Also included on the generator control panel are an operations switch and synchronizing lights for operating the set as a single unit or in parallel with other units. The engine section of the control panel contains switches for priming, starting, and stopping the engine and meters for monitoring set fuel level, oil pressure, and coolant temperature. Also included is an ammeter for the battery charging alternator. Electric/Electro-HydrauIic Governing System (Precise Sets Only). The electric governing system senses speed and load electrically and provides the controls and load responses necessary for effective single unit or parallel operation. The system consists of a rheostat for frequency adjustment, a load measuring unit for sensing load changes, and a governor control unit which signals the actuator for rapid governor response. The MEP-103A and some MEP-113A generator sets use an electro-hydraulic governing sys- tem, which includes a hydraulic actuator, a hydraulic pump, and a hydraulic sump. Other MEP-113A sets use an electric-magnetic actuator. Mechanical Governing System (Utility Sets Only). The mechanical governing system provides the controls and load responses necessary for efficient single unit, or parallel, operation of utility generator sets. Engine rpm and set frequency are controlled by the mechanical governor, an integral part of the fuel injection pump, which actuates the fuel metering valve. Adjustment of engine rpm and set frequency is accomplished by use of a manual speed control located adjacent to the control cubicle. This control is a knob type device which permits rapid frequency adjustment, locking in any position, and vernier adjustment for finer control. 1-3