Control System

An independent power plant incorporates an electronic control system that controls its operation, and monitors its operating parameters. Eniquest’s independent power plants incorporate a control station that houses the controller.

Regulating the Generator’s Output

The controller regulates the DC electricity that is supplied by the  Eniquest generator to the storage battery bank, to keep the storage battery bank’s voltage constant. It does this by adjusting the speed of the diesel engine that drives the alternator.  

As the speed of the engine is increased, the power delivered from the alternator increases. The controller controls the engine speed by operating an electromechanical actuator that adjusts the delivery of fuel to the diesel engine.


The controller monitors several parameters of the charging process and the engine. It does this both to control the storage battery bank charging process, and to provide warnings and information to the operator.  

The parameters that are monitored include:

⦁ Engine speed
⦁ Engine oil pressure
⦁ Engine temperature
⦁ Output voltage
⦁ Running state (running or not running)
⦁ Hours run.

Starting and Stopping the Engine

When the controller’s select switch is set to the Run position, or when the select switch is set to the Auto position and the controller receives a signal to start the engine, the controller performs a series of events called a start sequence.

The controller provides a warning in the form of a flashing light that the engine is about to start, and then starts the engine.

Monitoring the Storage Battery Bank

For Eniquest Outback models, and optionally for Eniquest Ranger models, a battery monitor monitors the amount of electrical energy in the storage battery bank (the state of charge). When the state of charge is reduced sufficiently the control system starts the Eniquest generator to recharge the batteries, and stops it when the storage battery bank is sufficiently charged.

To determine the state of charge of the storage battery bank, the battery monitor monitors its voltage. As the storage battery bank discharges its voltage falls slightly. When the voltage falls below a predetermined level the battery monitor signals the controller to start the Eniquest generator’s diesel engine.  As the storage battery bank is charged its voltage progressively rises.

When then voltage of the storage battery bank reaches a specified voltage, called the absorption voltage, the battery monitor signals the controller to stop the Eniquest generator’s diesel engine.