Areva MiCom P120, Technical Manual

Page: 46 / 668

P12x/EN FT/A96 User Guide
Page 10/72
MiCOM P120/P121/P122/P123
4. DISPLAYS OF ALARM & WARNING MESSAGES
Alarm messages are displayed directly on the front panel LCD. They have priority over the
default display presenting measured current values. As soon as the relay detects an alarm
condition (crossing of a threshold for example), the associated message is displayed on the
front panel LCD and the LED Alarm (LED 2) lights up.
We distinguish two types of alarm and warning messages:
-
Alarm messages generated by the electrical power network.
- Warning messages caused by hardware or software faults from the relay.
4.1 Electrical Network Alarms
Any crossing of a threshold (instantaneous or time delay) generates an "electrical network
alarm". The involved threshold is indicated. Regarding the phase thresholds, the phase
designation (A, B or C) is also displayed.
If several alarms are triggered, they are all stored in their order of appearance and presented
on the LCD in reverse order of their detection (the most recent alarm first, the oldest alarm
last). Each alarm message is numbered and the total number of alarm messages is
displayed.
The user can read all the alarm messages pressing
c
.
The user acknowledges and clears the alarm messages from the LCD pressing .
The user can acknowledge each alarm message one by one or all by going to the end of the
list to acknowledge, and clear, all the alarm messages pressing
.
The control of the ALARM LED (LED 2) is directly assigned to the status of the alarm
messages stored in the memory.
If one or several messages are NOT READ and NOT ACKNOWLEDGED, the ALARM LED
(LED 2) flashes.
If all the messages have been READ but NOT ACKNOWLEDGED, the ALARM LED (LED 2)
lights up continuously.
If all the messages have been ACKNOWLEDGED, and cleared, if the cause that generated
the alarm disappears, the ALARM LED (LED 2) is extinguished.
The different electrical system alarms are listed below:
Ie> 1
st
stage earth fault threshold
Ie>> 2
nd
stage earth fault threshold
Ie>>> 3
rd
stage earth fault threshold
I> PHASE 1
st
stage overcurrent threshold
I>> PHASE 2
nd
stage overcurrent threshold
I>>> PHASE 3
rd
stage overcurrent threshold
tIe> 1
st
stage earth fault time-out
tIe>> 2
nd
stage earth fault time-out
tIe>>> 3
rd
stage earth fault time-out
tI> PHASE 1
st
stage overcurrent time-out
tI>> PHASE 2
nd
stage overcurrent time-out
tI>>> PHASE 3
rd
stage overcurrent time-out
THERMAL ALARM thermal alarm threshold
THERMAL TRIP thermal trip threshold