MRF3

Productomschrijving

The MRF3 is a universal frequency relay and contains the protective functions required by most electrical utilities for mains parallel operation of power stations:
• Four elements for over- or under frequency protection
• Two elements for frequency gradient supervision df/dt
• Fast decoupling of the generator from the grid at mains failure
• Suitable for load shedding systems

Features
• Microprocessor technology with watchdog
• effective active low pass filter for suppressing of harmonics,
• four elements for frequency supervision, alternatively for under- or over frequency
• detection,
• adjustable reconnection values for the frequency stages
• independent separate adjustable timers,
• adjustable voltage threshold for blocking and disconnection of the frequency Measurement,
• Reclaim time of output relays after the frequency has been exceeded or fallen short of.,
• display of all measuring values and setting parameters for normal operation and tripping via an alpha-numerical display and LEDs,
• display of actual measuring values, storage and display of tripping values,
• minimum- and maximum measurement of the frequency gradient,
• adjustable tripping window for the df/dt supervision at mains decoupling application,
• the protective functions can be assigned individually to the output relays (relay matrix),
• display of measuring values as primary quantities,
• storage and display of tripping values in a fault memory (voltage-failure safe),
• recording of up to eight fault occurrences with time stamp in the fault recorder,
• External triggering of the fault recorder
• Recording of external functions as digital track in the fault recorder*
• for blocking the individual functions by the external blocking input, parameters can be set according to requirement,
• safe and fast mains decoupling by df/dt supervision,
• suppression of indication after an activation (LED flash),
• display of date and time,
• in compliance with VDE 0435, part 303 and IEC 255,
• serial data exchange via RS485 interface possible; alternatively with RS485 Pro- Open Data Protocol or Modbus Protocol.
* Modbus Protocol only