Product/Technical Services

Busbar Protection GRB100

Product Overview

GRB100 is a numerical low impedance differential relay for busbar protection, available in centralised and de-centralised configurations. GRB100 can be applied for various busbar systems, such as single busbar, double busbar, one and a half busbar, four bus-coupler busbar, ring busbar and busbar with transfer bus. Two differential elements for check zone and discriminating zone, a countermeaure for CT saturation and optional undervoltage fault detectors provide for an extremely high degree of reliability. Optional circuit breaker failure protection is available, and in addition there are standard GR-series features such as metering, data recording and communications.

Technical Description

Protection functions

  1. Percentage restraint characteristic to ensure stability against external faults arising from CT errors

  2. Countermeasure for CT saturation caused by d.c. offset current

  3. High sensitivity, high speed operation (less than 1 cycle)

  4. Centralized or decentralized installation

  5. Easy extension for future feeders (Up to 32 feeders)

  6. Circuit breaker failure protection (option)


Metering and recording functions

  1. Metering
    - Currents, differential currents, voltages, frequency

  2. Recording
    - Event record
    - Fault record
    - Disturbance record

  3. Calendar and Time
    - IRIG-B port for external clock

Menu-driven human interfaces

  1. Liquid Crystal Display (LCD) display with operation keys
    - Relay setting and data display

  2. Personal computer (PC) interface
    - Relay setting
    - Recorded data display
    - Waveform analyzing

Automatic supervision

  1. Automatic monitor

Fault detector (Option)

  1. Serial redundancy for tripping