Areva MiCOM P921, Technical Manual, Page: 21 / 376

Technical Guide P92x/EN GS/E11
Getting Started
MiCOM P921-P922-P923 Page 7/18
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· Under the bottom hinged cover:
- battery compartment to hold the ½AA size battery which is used for memory
back-up for event, fault and disturbance records (P922 and P923 only).
-
a 9-pin female D-type front port for communication with a PC locally to the
relay (up to 15m distance) via a RS232 serial data connection (SK1 port).
The fixed function LEDs on the left hand side of the front panel are used to indicate
the following conditions:
LEDS Colour Labels Significance
LED1 Red Trip. LED 1 indicates when a trip order has been
issued by the relay to the cut-off element (circuit
breaker, contactor). This LED recopies the trip
order issued to the trip output contact (RL1). Its
normal state is unlit. It is illuminated as soon as
a trip order is issued. It goes out when the
associated alarm is acknowledged (by pushing
the 0 key).
LED2 Yellow Alarm LED 2 indicates that an alarm has been
registered by MiCOM P921, P922 or P923
relays. The alarms are either threshold
crossings (instantaneous), or tripping orders
(time delayed). 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.
LED3 Orange Equip Failure LED 3 is dedicated to the internal alarms of
MiCOM P921, P922 and P923 relays. When a
« non critical » internal alarm (typically
communication Fault) is detected, the LED
flashes continuously. When the Fault is classed
as « critical », the LED is illuminated
continuously. The extinction of this LED is only
possible by the disappearance of the cause that
caused its function (repair of the module,
disappearance of the Fault).
LED4 Green Aux Supply LED 4 indicates that MiCOM P921, P922 and
P923 relays are in correct working order.
LED5 to
LED8
Red Aux1 to Aux4 These LEDs can be programmed by the user on
the basis of information on available thresholds
(instantaneous and time-delayed). The user
selects the information he wishes to see
associates with each LED from the menu
element (Logic OR). Each LED illuminates when
the associated information is valid. The
extinction of each LED is linked to the
acknowledgement of the associated alarms.