Areva MiCOM P441, Technical Manual

Page: 108 / 636

P44x/EN IT/E33 Introduction
Page 6/24 MiCOM P441/P442 & P444
The front panel of the relay includes the following, as indicated in figure 1:
•
a 16-character by 2-line alphanumeric liquid crystal display (LCD).
•
a 7-key keypad comprising 4 arrow keys
(
!
,
"
,
#
and
$
),
an enter key (
%
), a clear key (
!
), and a read key (
&
).
•
12 LEDs; 4 fixed function LEDs on the left hand side of the front panel and 8
programmable function LEDs on the right hand side.
Under the top hinged cover:
•
the relay serial number, and the relay’s current and voltage rating information*.
Under the bottom hinged cover:
•
battery compartment to hold the
1
/
2
AA size battery which is used for memory
back-up for the real time clock, event, fault and disturbance records.
•
a 9-pin female D-type front port for communication with a PC locally to the relay (up to
15m distance) via an EIA(RS)232 serial data connection.
•
a 25-pin female D-type port providing internal signal monitoring and high speed local
downloading of software and language text via a parallel data connection.
The fixed function LEDs on the left hand side of the front panel are used to indicate the
following conditions:
Trip (Red) indicates that the relay has issued a trip signal. It is reset when the associated
fault record is cleared from the front display. (Alternatively the trip LED can be configured to
be self-resetting)*.
Alarm (Yellow) flashes to indicate that the relay has registered an alarm. This may be
triggered by a fault, event or maintenance record. The LED will flash until the alarms have
been accepted (read), after which the LED will change to constant illumination, and will
extinguish when the alarms have been cleared.
Out of service (Yellow) indicates that the relay’s protection is unavailable.
Healthy (Green) indicates that the relay is in correct working order, and should be on at all
times. It will be extinguished if the relay’s self-test facilities indicate that there is an error with
the relay’s hardware or software. The state of the healthy LED is reflected by the watchdog
contact at the back of the relay.
3.1.2 Relay rear panel
The rear panel of the relay is shown in figure 2. All current and voltage signals, digital logic
input signals and output contacts are connected at the rear of the relay. Also connected at
the rear is the twisted pair wiring for the rear EIA(RS)485 communication port, the IRIG-B
time synchronising input and the optical fibre rear communication port which are both
optional.