Table of Contents
Advertisement
ABB Substation Automation
Products and Systems
4.1.4
4.1.5
1MRS750940-MUM
Technical Reference Manual
Monitoring
The function of the relay can be monitored with the help of three indicators on the
relay front panel: a green READY LED, a yellow START LED and a red TRIP LED.
In addition, in case of an internal fault or an alarm from the protection stages, a text
message appears on the display.
The messages on the LCD have a certain priority order. If different types of
indications are activated simultaneously, the message with the highest priority appears
on the display.
The priority order of the messages:
1 Internal fault
2 Trip, CBFP
3 Start
Self-supervision (IRF)
The relay is provided with an extensive self-supervision system that continuously
supervises the software and the electronics of the relay. It handles run-time fault
situations and informs the user about an existing fault via a LED on the MMI and a
text message on the LCD.
When a fault is detected, the relay first tries to eliminate it by restarting. Only after
the fault is found to be permanent, the green READY indicator starts to blink and the
protection relay delivers a fault signal to the self-supervision output contact. All other
output contacts are blocked during an internal fault. Further, a fault indication text
appears on the LCD.
Fault indication has the highest priority on the MMI. None of the other MMI
indications can override the IRF indication. When the display panel has received a
fault indication, the indication text remains on the LCD. As long as the green LED is
blinking, the fault indication or the green LED can not be turned off. In case an
internal fault disappears, the fault indication text remains on the display. The green
READY indicator stops blinking and the alarm output IRF is released to normal
service state.
The IRF code is the code of the latest internal fault detected by the self-supervision
system. It describes the type of the fault. When a fault appears, the code is to be
recorded and given to an authorised repair shop when overhaul is ordered. For fault
codes, refer to "Operator's Manual".
REJ 523
31
Advertisement
Table of Contents
