High Impedance Differential Relay GRB150
We reserve the right to introduce improvements in the course of technical development.
GRB150 provides the following metering and recording
■Numerical high impedance differential protection ■Event recording
■Busbar protection ■Disturbance recording
■Restricted earth fault protection
■High speed operation GRB150 provides the following human interfaces for relay
■Secure operation against CT saturation settings or viewing of stored data.
■Single-or three-phase models ■Relay front panel: LCD, LED display and operation keys
■CT supervision ■Local PC
■Voltage limiting by varistors ■Remote PC
■Configurable binary outputs
■Automatic monitoring The relay can be accessed from a local PC or a remote PC
■Metering and recording functions through communication ports.
■Menu-driven human interfaces A local PC can be connected to the relay via the RS232C
■Two serial ports for a local PC and a remote PC port on the front fascia of the relay and a remote PC can be
■IRIG-B port for external clock connected to the relay through the RS485 port at the rear of
GRB150 has two model series, model 101 and model 201.
APPLICATION Model 101 is for single-phase applications and used for
restricted earth fault protection. Model 201 is for three
GRB150 is a numerical high impedance differential relay.
phase applications and used for three-phase protection.
The relay provides high impedance differential protection
and can be applied for:
■Restricted earth fault protection
■Single, double, or one-and-a-half busbar protection FUNCTIONS
■T-zone protection of one-and-a-half busbar arrangement
■Short line cable protection
GRB150 is applied for high impedance differential
Typical connection examples are as shown in Figure 1 protection. The high impedance differential protection
(restricted earth fault protection) and Figure 2 (busbar exhibits stable operation even if the CT at the out feeding
protection). end of the circuit is saturated by the fault current.
The relay features CT secondary supervision.
When a failure occurs in the secondary of the CT circuit,
■the LED "ALARM" on the relay front panel is illuminated,
■the CT secondary circuit failure condition is indicated on
■the CT secondary circuit failure condition is recorded in the
■and an Alarm is generated from a binary output contact
The user can select to block or to operate the relay on CT
secondary circuit failure.
The GRB150 provides the following varistor units.
■EBB phase varistor unit
▲Fig. 1 Restricted earth fault protect on (single phase model) ■EB-102: Three phase varistor unit
The varistor unit includes a varistor and stabilizing resistor.
The varistor, which is a non-linear resistor, is used to protect
against a large voltage on the secondary side of the main
CT generated during a fault. The characteristic is as shown
in Figure 3.
▲Fig. 2 Busbar protection (three phase model)
METERING AND RECORDING
■ Metering and Monitoring
The differential voltage is measured continuously and
displayed on the LCD on the relay fascia, at the local PC,
and the remote PC when connected, and is indicated as a
The user can monitor the following output and status on the
LCD and at local/remote PCs.
■Relay element output
▲ Fig. 3 Characteristic of varistor
■ Event Record
The most recent 96 time-tagged events are stored with 1
ms resolution. Events recorded are as follows.
Figure 4 shows the hardware block diagram of the relay. ■Change of binary input signal
The relay has a microprocessor design. The ■Change of relay setting
microprocessor performs software functions such as signal ■Relay failure
processing, protection algorithm, scheme logic, output relay
control and handling of the human interface. ■ Fault Record
Analog inputs include phase current inputs or residual
current input. The number of analog inputs depends on the A relay trip initiates fault recording. Time-tagged fault data
model of the relay. can be stored for the 8 most recent faults. Fault record
The internal auxiliary transformers are used to isolate, step items are as follows.
down and condition the inputs from the CTs. Their output
signals are then converted into digital data for further ■Date and time
processing. ■Operating phase(for model 201)
The front panel contains a 2X16 character, liquid crystal ■Differential voltage data
display(LCD) and 9 pushbutton keys to provide local access
to the relay menu. ■ Disturbance Record
There are also 6 light emitting diodes(LED) for visual The relay can record 3 analog and 7 binary signals. The
indication of the status of the relay. disturbance recorder is initiated by relay tripping.
The relay provides three communication ports, RS232C for
connection of a local PC, RS485 for a remote PC and Pre-fault recording time is fixed at 300ms, and post-fault
IRIG-B for an external clock. recording time is user selectable from 100ms to 3s. The
maximum number of stored records depends on the
post-fault recording time. In the case of a post-fault
recording time of 500 ms, up to 20 disturbance records can
be stored. The record number of the recorded data is
displayed on the LCD.
■ Calendar and Time
The calendar and time are provided for time tagging of
recorded data. Synchronization with GPS(Global
positioning system) is achieved via the IRIG-B port.
▲ Fig. 4 Hardware block diagram
The terminal blocks are located at the rear of the relay ■ Relay Front Panel
providing connections for all input and output circuits.
The relay front panel incorporates the following human
The relay is housed in the case shown in Figure 9. interfaces. Setting the relay and viewing stored data are
possible using the Liquid Crystal Display(LCD) and operation with RSM100 software.
■16 characters, two line LCD with backlight ■Metering
■Six Light Emitting Diodes(LED) including two that are ■Event records
configurable ■Fault records
■Operation keys ■Disturbance records
■ Remote Setting and Monitoring(RSM)
Figure 5 shows the relay front panel. GRB150 can be connected to the RSM system via the
RS485 interface at the rear of the relay.
The user can operate the relay from a remote PC in the
same way as from a local PC.
A maximum of 32 relays can be connected to the remote
PC in multi-drop mode, via the protocol converter(option).
The RSM100 software is also used to communicate with the
relay and to view or analyze disturbance records on the
Data transmission rate between relays and the protocol
converter is 64kbps.
The relay is compliant with the transmission protocol
▲ Fig. 5 Relay front panel defined by IEC 60870-5103.
Figure 6 shows the configuration of the RSM system.
The following items are displayed on the LCD.
■The number of disturbance records
■Any failure message detected by the automatic monitoring
Password protection can be provided from the setting menu on
the LCD to provide security for relay setting changes. After the
password has been set, the password must be entered to
access the setting menu from a local or remote PC as well as
on the LCD.
The contents of metering, fault records, and relay failures can
be monitored by pressing the VIEW key. The VIEW key can be
pressed without removing the relay front cover.
Arbitrary signals can be assigned to the two user configurable ▲Fig. 6 Remote setting and monitoring system
Two monitoring jacks are operable when the test mode is
selected in the LCD window. An oscilloscope can be connected ■ Relay Setting
to the relay through these jacks. Selection of output signals on The user can input or change settings using the operation
the monitoring jacks can be set from the menu. keys on the relay fascia or via a local or remote PC with the
RSM system. Password protection is provided to change
■ Local PC settings.
The user can communicate with the GRB150 even from a local Four active setting groups are provided. This allows the
PC via the RS232C port on the relay fascia. The following data user
can be viewed or analyzed on the local PC to set one group for normal operating conditions while other
groups may be set to cover alternative operating conditions.
■ Configurable Binary Output Contacts
GRB150 is provided with 6 user configurable normally open
output contacts for indication and alarm.
■ Binary Inputs
GRB150 is provided with a binary input for indication reset.
The binary input circuit is provided with a logic level
■ Automatic Monitoring Function
The automatic monitoring function will detect failures,
should they occur, that might cause unwanted operation.
The items monitored include the following:
■Watch Dog Timer
■DC power supply circuits
In the unlikely event that a relay failure should occur, this is
detected by automatic monitoring and the LED ALARM on
the relay fascia is illuminated. A binary "RELAY FAILURE"
output is simultaneously operated and the date/time of any
such failure would be stored in the event record.
■ Ratings ■ Binary inputs
■AC Voltage: 300V Minimum operating voltage: 70Vdcat 110V/125Vdc rating
■DC power supply: 110Vdc/125Vdc (Operative range: 88 to
150Vdc) ■ Contact ratings
220Vdct25OVdc (Operative range: 176 to
100Vdc) Trip contacts:
48Vdc/54Vdc/6OVdc (Operative range: 38.4 ■Make and carry: 5A continuously
to72Vdc) ■Make and carry: 30A, 290Vdc for 0.5s (L/R=10ms)
AC ripple on DC supply IEC 60255-11: maximum 12% ■Break: 0.15A, 290Vdc (L/R=40ms)
DC supply interruption IEC 60255-11
Permissive duration of DC supply voltage interruption to Auxiliary contacts:
maintain normal operation: less than 50ms at 110Vdc ■Make and carry: 4A continuously
Restart time: less than 10s ■Make and carry: 20A, 290Vdc for 0.5s (L/R>5ms)
■Binary input circuit DC voltage: ■Break: 0.1 A, 290Vdc (L/R=40ms)
11 OVdc/125Vdc (Operative range: 88 to 150Vdc)
20Vdr-/25OVdc (Operative range: 176 to 300Vdc) Durability
48Vdc/54Vdc/6OVdc (Operative range: 38.4 to 72Vdc) ■Loaded contact: 10,000 operations minimum
■Unloaded contact: 100,000 operations minimum
■ Overload rating
■ Mechanical design
■AC voltage input: 300V continuous
1 kV for 0.4s
■Weight: 5kg(without varistor unit)
■ Burden Varistor unit EB-101:10kg
■Input impedance: 660Ω with EB-101 or-102 Varistor unit EB-102:14kg
■DC power supply: less than 10W(quiescent) ■Case color: Munsell No.10YR8/0.5
less than 15W(operation) ■Isolation: IP51
■Binary input circuit: 0.5W/input at 110Vdc ■Installation: Flush mounting except for varistor unit
■ High impedance differential protection ■ Vibration test
■Differential protection: 10 to 600V in 1 V step The relay withstands vibration in the frequency range of 10 to
■Supervisory: 5 to 100V in 1 V step 150Hz with a sweep rate of 1 octave per minute in accordance with
IEC Standard 6025521-1, Class 1.
■ Operating and resetting time
■Operating time: typical 15ms
■ Shock and bump test
■Resetting time: less than 100ms The relay withstands the shocks and bumps specified in IEC
Standard 60255-21-2, Class 1.
■ Accuracy of differential element
■ Seismic test
■Differential protection: ±5%w at more than 50V The relay withstands the seismic specified in IEC Standard
■Supervisory: ±5% at more than 20V 6025521-3, Class 1.
■Communication port ■ Dielectric test
Front communication port (local PC) The relay withstands 2kV at 50 or 60Hz for 1 minute between all
■Connection: Point to point circuits and the case, and between all separate circuits in
■Cable type: Multi-core (straight) accordance with IEC Standard 60255-5. The relay withstands 1 kV
■Cable length: 15m (max.) at 50 or 60Hz for 1 minute across the open contacts in accordance
■Connector: RS232C 9-way D-type female with ANSI/IEEEC37.90.
Rear communication port (remote PC)
■Signal level: RS485 ■ Impulse voltage test
■Transmission data rate for RSM system: 64kbps The relay withstands 5kV peak and 1.2/504s, 0.5J waveform
■Connection: Multidrop mode (max. 32 relays) applied both transversely and between relay terminals and earth in
■Connector: Screw terminals
accordance with IEC Standard 60255-5.
■Cable and length: Twisted pair cable, max. 1200m
■Isolation: 2kVac for 1 min.
■Transmission data rate for-protocol IEC 60870-5-103: 9.6, ■ 1MHz burst disturbance test
19.2kbps The relay withstands 1 MHz, for 2s with 2.5kHz, 2.5kV attenuated
Interface to optical fibre can be provided for IEC60870-5-103. to half in 3 to 6 cycles between independent circuits and
Connector type: ST type independent circuits and case earth, and 1.0kV across terminals of
the same circuit in accordance with IEC Standard 60255-22-1,
■ IRIG-B port Class 3.
■Connection: BNC connector
■Cable type: 50ohm coaxial cable ■ Radiated electromagnetic field
■ Atmospheric environment The relay withstands 25 to 1000MHz, 10V/m radiated field in
Temperature (IEC 60255-6) accordance with IEC Standard 60255-22-3, Class 3.
■Operation guarantee: -10℃ to + 55℃
■Storage: -20℃ to + 70℃
Humidity (IEC 60068-2-3): 4 days at 93%, and 40℃
■ Electrostatic discharge test
The relay withstands following magnitude of electrostatic discharge
in accordance with IEC-60255-22-2.
■Contact discharge:6kV, Class 3
■Air discharge: 15kV, Class 4
■ Fast transient disturbance test
The relay withstands 4k±10%, 2.5kHz applied in common mode,
at least 1 minute in accordance with IEC Standard 60255-22-4,
■ Surge immunity
The relay withstands 4kV peak and 1.2/50ms between all groups
and case earth, and 2kV peak and 1.2/50ms between terminals of
each group in accordance with IEC Standard 61000-4-5. Level 4.
■ Protocol converter (Option)
■AC power supply
Frequency: 50 or 60Hz
Burden: less than 20W
■Transmission data rate
PC side (RS232C): 9.6, 19.2, 38.4kbps
Relay side (RS485): 64kbps
1.High Impedance Differential Relay GRB150 A 0 0
High impedance differential relay GRB150
-Single phase application (with EB-101) 101
-Three phase application (with EB-102) 201
DC power supply rating:
EB-101:Varistor unit for single phase
EB-102:Varistor unit for three phase
2.Protocol Converter (option)
Protocol converter G1PR1
Not provided with external time synchronization 01
Provided with external time synchronization (TRIG-B) 02
Provided with external time synchronization (TRIG-B and GPS) 03
AC power supply rating:
AC 100/110V 10
POWER SYSTEMS & SERVICES COMPANY
UTILITY POWER SYSTEMS ENGINEERING DEPT.
1-1, SHIBAURA 1-CHOME, MINATO-KU, TOKYO 105-8001, Japan
6337-1 ’01-1 C1.5