FEATURES

DECS-400 features and capabilities are listed below. The paragraphs following the list describe major

DECS-400 features and functions in more detail.

• Five excitation control modes

− Automatic Voltage Regulation (AVR)

− Field Current Regulation (FCR)

− Field Voltage Regulation (FVR)

− Power Factor (PF)

− Var

• Two pre-position setpoints (with adjustable traverse rate) for each excitation control mode

• Two PID groups

• Programmable analog control output selectable for 4 to 20 mAdc, –10 to +10 Vdc, or 0 to +10 Vdc

• Remote setpoint control input accepts analog voltage or current control signal

• Real-time metering

• Integrated power system stabilizer (PSS)

− Generator or motor control modes, accommodates phase rotation changes between modes

− Speed and power sensing or speed-only sensing

− Two-wattmeter or three-wattmeter methods of power measurement

• Soft start and voltage buildup control

• Four limiting functions

− Stator current

− Overexcitation

− Underexcitation

− Underfrequency compensation

− Reactive power

• Ten protection functions

− Field overvoltage

− Field overcurrent

− Generator undervoltage

− Generator overvoltage

− Loss of sensing voltage

− Generator frequency less than 10 hertz

− Loss of field (40Q)

− Field overtemperature

− Volts per hertz (24)

− Exciter diode failure

• IRIG time synchronization

• Sixteen contact inputs

− Six fixed-function inputs: AVR, Manual, Lower, Raise, Start, and Stop

− Ten user-programmable inputs

• Eight contact outputs

− Two fixed-function outputs: Watchdog, On/Off

− Six user-programmable outputs, configurable for maintained, latched, or momentary operation

• Four communication ports

− Front RS-232 port for interface with PC running BESTCOMS software

− Rear RS-485 port for dedicated communication with secondary, redundant DECS-400

− Rear RS-485 port using Modbus™ protocol for communication with remote terminal

− Rear RJ-45 port connects to onboard modem that provides dial-in and dial-out capability

• Data logging, sequence of events recording, and trending