TM 9-6115-730-24
FIELD LEVEL MAINTENANCE
TACTICAL QUIET GENERATOR 200 kW, 50/60 Hz MEP-809A/PU-809A
THEORY OF OPERATION
GENERAL
This work package contains functional descriptions of the generator set and explains how TQG functional
systems interact with one another.
ENGINE OVERVIEW
The 200 kW TQG is powered by an in-line six cylinder diesel engine. The engine firing order is 1-5-3-6-2-4. The
engine rotation is counterclockwise when the engine is viewed from the flywheel end (rear) of the engine. The
engine uses a turbocharger and an air-to-air aftercooler. The engine cylinder bore is 5.12 inch (130 mm) with
stroke of 5.91 inch (150 mm). Total displacement is 732 cu. in. (12.0L). The engine electronic unit injector system
(EUI) eliminates mechanical components that are used in a pump-and-line system. The EUI provides increased
control of the timing and increased control of the fuel air mixture. The timing advance is achieved by precise
control of the unit injector timing. Adjusting injection duration controls engine rpm. An engine speed sensor
provides information to the Engine Control Module (ECM) for detection of cylinder position and engine rpm. The
engine has built-in diagnostics to ensure that all of the components are operating properly. In the event of a system
component failure, the operator will be alerted via the Generator Set Control (GSC) component of the TQG
Electronic Modular Control Panel (EMCP). Numerical codes of the faulty component or condition are displayed on
the GSC. Intermittent faults are logged and stored in the ECM memory.
Engine Control Module
The Engine Control Module (ECM) automatically provides the correct amount of fuel in order to start the engine.
The ECM is integrated with the engine fuel system and the engine air inlet and exhaust system to control the fuel
delivery and the injection timing electronically. The ECM provides timing control and fuel air ratio control. Injection
timing is achieved by the precise control of the injector firing time. Adjusting the injection duration controls engine
rpm. ECM energizes unit injector solenoids to start the injection of fuel and de-energizes the unit injector
solenoids to stop the injection of fuel.
Electronic Components
The engine uses three types of electronic components: input, control, and output. Input components send variable
electrical signals (voltage, frequency, or pulse width (PW)) to the ECM. ECM interprets input signals about the
condition, environment, or operation of the TQG. ECM firmware evaluates input data to control engine
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