TRUST. WELL EARNED. PRISMIC® A12 Excitation Controllers The PRISMIC® A12 excitation controller has been designed to control the excitation of a brushless generator. It incorporates the latest digital micro controller technology to make it the most comprehensive and compact controller available. Introduction The PRISMIC® A12 is based upon proven technology and combines the experience and hardware of the complete range of BRUSH PRISMIC® products. It includes, additional features such as intergrated speed detection, power system stabiliser and synchronisation. The PRISMIC® A12 is produced on a plate mounted system either as a single channel or twin channel arrangement. As a twin system each controller acts as a hot standby for the other and is independently controlled with auto tracking, and smooth transfer. An optional colour display screen is also available. Key Features • Complete excitation system mounted on a plate • Available either as a single unit or as a high integrity twin configuration • Integrated Power System Stabiliser (optional) • Integrated auto synchroniser (optional) • Integrated speed detection eliminating need for seperate speed switch • Rotor earth fault detector input included eliminating the need for separate unit • Negative forcing of exciter field voltage • Modes of operation include generator terminal voltage control, power factor control, VAr control and offload VArs • Digital Outputs • Analogue Input Signal for special application • Auxiliary power supply input allows easy setting of unit without PMG supply present • Manual Reference • Soft start for controlled application of excitation • Diode Failure Detection and Indication-• HMI (Human Machine Interface) software for advanced maintenance diagnostics and downloading of data • Oscilloscope style trending and analogue data logging (5ms resolution) via HMI • Event Logging • Externally mounted display interface computer (Optional) • Automatic and manual excitation limiters The following limiters are included: • Under Excitation Limiter • Over Excitation Limiter • Over Flux (V/Hz) Limiter • Stator Current Limiter • Fast Acting Field Current Limiter • Terminal Voltage Limiter Automatic transfer of control to hot standby channel initiated by: • Over Voltage Monitor Triggered • Under Voltage Monitor Triggered • Over Excitation Monitor Triggered • Under Excitation Monitor Triggered • Over Flux Monitor Triggered • Voltage Sensing Error • The PRISMIC® A12 includes the following communication port - 1 x RS232 service port - 1 x CANbus port for communication with hot standby unit in twin configurations - 1 x CANbus port available for connection of display interface computer - 1 x RS485 / RS232 Modbus RTU port for SCADA/ DCS communi

Ratings Max continuous output current 20A Max 10 second output current 30A Nominal sensing voltage: 100V to 120V Underexcitation Limiter Underexcitation Monitor Auxiliary power supply: 24V d.c. Voltage sensing phases: Either 3 phase or 1 phase Excitation supply frequency: 48Hz to 480Hz Excitation supply voltage: Single phase 85 to 264V Overexcitation Limiter Overexcitation Monitor Limiter and Monitor Settings Nominal generator frequency: 50Hz or 60Hz Current transformer input nominal: Either 5A or 1A Current transformer input burden: Less than 0.5VA Maximum field voltage for forcing: 75% of available...