Chapter 1 - 7SR45 Description of Operation
©2018 Siemens Protection Devices Limited Chapter 1 Page 20 of 48
2.6.3 Light Emitting Diode (LED)
2.6.3.1 Indication
The 7SR45 Argus relay consists of 9 non-programmable LEDs. LED indicates the operating status of the relay
such as TRIP READY and PICKUP.
The pre-defined LED functions are:
Table 2-1
LED Functions
LEDs
Predefined Names
Indication Color
Functions
LED 1
PROT. HEALTHY
GREEN
Indicates the relay protection function in a healthy state
LED 2
TRIP
RED
The trip indication for the phase/earth faults
LED 3
PICKUP
AMBER
The pickup indication for the phase/earth faults
LED 4
IL1 / A
RED
The pickup indication for phase A fault
LED 5
IL2 / B
RED
The pickup indication for phase B fault
LED 6
IL3 / C
RED
The pickup indication for phase C fault
LED 7
IE / E
RED
The pickup indication for Derived/Measured Earth fault
LED 8
TRIP READY
GREEN
The sufficient energy available for tripping
LED 9
LOW BATTERY
AMBER
The battery voltage is less than the operating level
2.6.3.2 Protection Healthy LED
The steady illumination of Protection Healthy LED indicates that the required CT current 0.20xIn (minimum phase
current) in single phase or 0.10xIn (minimum phase current) in three phases or auxiliary power supply is applied
to the relay and the relay is functioning healthy.
2.6.3.3 Trip Ready LED
The steady illumination of Trip Ready LED indicates that required CT current 0.20xIn (minimum phase current)
in single phase or 0.10xIn (minimum phase current) in three phases or auxiliary power supply is applied to the
relay and the relay is having sufficient energy to trip through the impulse output.
2.6.3.4 Low Battery LED
The low battery LED indicates when the battery voltage falls below the sufficient operating voltage.
2.6.4 Local Flag
An electromechanical bi-stable flag is provided in the front fascia to indicate the trip condition. The status of flag is
GREEN in normal condition and turns RED during the trip condition.
NOTE:
The energy required to show the trip indication is provided by the auxiliary voltage or phase currents.
The flag indicates a trip indication when any protection function operates or any binary inputs are mapped to trip
pulse output.
The trip indication is retained even in the absence of auxiliary voltage and phase currents.
The trip indication can be reset with any power mode. Refer to
Modes of operation
.