Micom P721, Technical Manual

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User Guide P72x/EN FT/C21
MiCOM P721/P723 Page 7/38
1.1.4 LEDs
The LED labels on the front panel are by default written in English, however the user has
self-adhesive labels available with
MiCOM relays on which it is possible to write using a ball
point pen.
The top four LEDs indicate the status of the relay (Trip condition, alarm LED, equipment
failure, auxiliary supply).
The four lower LEDs are freely programmable by the user and can be assigned to display a
threshold crossing for example (available for all models) or to show the status of the logic
inputs.The description of each one of these eight LEDs located in the left side of the front
view is given hereafter (numbered from the top to bottom from 1 to 8):
LED 8
LED 1
P3951ENa
LED 1 Colour: RED Label: Trip
LED 1 indicates that the relay has issued a trip order to the cut-off element. This LED
recopies the trip order issued to the Trip logic output. Its normal state is unlit. As soon as a
triggering order is issued, the LED lights up. It is cleared when the associated alarm is
acknowledged either through the front panel, or by a remote command, a digital input, or by
a new fault (CONFIGURATION/Alarms menu).
LED 2 Colour: ORANGE Label: ALARM
LED 2 indicates that the relay has detected an alarm. This alarm can either be a threshold
crossing (instantaneous), or a trip order (time delayed). As soon as an alarm is detected, the
LED starts blinking. After all the alarms have been read, the LED lights up continuously.
After acknowledgement of all the alarms, the LED is extinguished.
NOTE: It is possible to configure the instantaneous alarms to be self reset or
not by choosing Yes or No in the CONFIGURATION/Alarms Menu.
The alarm LED can be reset either through the front panel, or by remote command, by a
digital input, or by a new fault (CONFIGURATION/Alarms menu).
LED 3 Colour: ORANGE Label: Warning
LED 3 indicates internal alarms of the relay. When the relay detects a « non critical » internal
alarm (typically a communication failure), the LED starts blinking continuously. When the
relay detects a fault that is considered as « critical », the LED lights up continuously. Only
the disappearance of the cause of the fault can clear this LED (repair of the module,
clearance of the Fault).
LED 4 Colour: GREEN Label: Healthy
LED 4 indicates that the relay is powered by an auxiliary source at the nominal range.
LED 5 to 8 Colour: RED Label: Aux.1 to 4.