Section Ill. PRINCIPLES OF OPERATION

TM 9-6115-662-13&P Section Ill. PRINCIPLES OF OPERATION 1-13 FUNCTIONAL DESCRIPTION. 1-13.1 Power Unit Functional Description. The Power Units are mobile power sources and consist of one Tactical Quiet 30 kW Generator Set mounted on a modified trailer. The generator set has a liquid-cooled diesel engine, brushless generator, excitation system, speed governing system, fuel system, 24-volt direct current starting system, control system, and malfunction protection system. The generator set has a reconnection board that has been initially positioned to allow power output of either 120/208-volt, three phase or 240/416-volt, three phase AC power. The PU-803 uses a DOD Model MEP-805A Generator Set operating at 50/60 Hz with a load capacity of 30 kW. The PU-804 uses a DOD Model MEP-815A Generator Set operating at 400 Hz. System or equipment load cables are to be connected to the load terminals on the generator set output panel. Refer to TM 9-6115-644-24 for functional description of the generator set. Refer to TM 9-2330-205-14&P for functional description of the trailer. 1-13.2 Power Plant Functional Description. The Power Plant consists of two PU-803 Power Units, a switch box and power cable. The two PU-803 Power Units have been modified to provide independent switching between the Power Units. One PU-803 is modified by moving the accessory storage box to the curbside fender, adding a switch box and identifying the modified PU-803 as AN/MJQ-40 unit A. The other PU-803 is modified by adding a power cable and identifying the modified PU-803 as AN/MJQ-40 unit B. Refer to paragraph 1-13.1 for the functional description of the PU-803. Output electrical power is normally supplied through the switch box assembly located on unit A. The cable supplied with unit B connects the generator sets through the switch box on unit A. The control panel of the switch box controls the output source. The output source is usually either the unit A or unit B generator set as determined by the control panel switches S1 and S2. When both switches are placed in the ON position and both generators are on, the generators operate in parallel. The parallel operation of the generators allows for an uninterrupted load transfer between unit A and unit B. The output power cable to external equipment may be connected to the switch box from either the connector J1 or load terminals (L0, L1, L2, L3, and GND) of the switch box. If the switch box becomes unserviceable, the load cable may be connected to the load terminals on the output panel of one of the generator sets. When connection is required from the generators, parallel operation is not lost. Refer to TM 9-6115-644-10 for operation and TM 9-6115-644-24 for detailed functional description of the generator sets without a switch box. Refer to TM 9-2330-205-14&P for a detailed functional description of the trailer. 1-14 RELATED TECHNICAL MANUALS. Refer to appendix A for related technical manuals and lubrication order. 1-9 (1-10 Blank)