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)
