Siemens 7SR242 Manual page 15

7SR242 Duobias Description Of Operation
The warning and information labels on the relay fascia provide the following information:
Liquid Crystal Display (LCD)
A 4 line by 20-character liquid crystal display indicates settings, instrumentation, fault data and control
commands.
To conserve power the display backlighting is extinguished when no buttons are pressed for a user defined
period. A setting within the "SYSTEM CONFIG" menu allows the timeout to be adjusted from 1 to 60 minutes and
"Off" (backlight permanently on). After an hour the display is completely de-activated. Pressing any key will re-
activate the display.
The LCD contrast can be adjusted using a flat blade screwdriver to turn the screw located below the contrast
symbol . Turning the screw clockwise increases the contrast, anti-clockwise reduces the contrast.
'PROTECTION HEALTHY' LED
This green LED is steadily illuminated to indicate that DC voltage has been applied to the relay power supply and
that the relay is operating correctly. If the internal relay watchdog detects an internal fault then this LED will
continuously flash.
'PICKUP' LED
This yellow LED is illuminated to indicate that a user selectable function(s) has picked up. The LED will self reset
after the initiating condition has been removed.
Functions are assigned to the PICKUP LED in the OUTPUT CONFIG>PICKUP CONFIG menu.
'TRIP' LED
This red LED is steadily illuminated to indicate that a user selectable function has operated to trip the circuit
breaker. Functions are assigned to the 'Trip' LED using the OUTPUT CONFIG>Trip Contacts setting.
Operation of the LED is latched and can be reset by either pressing the TEST/RESET► button, energising a
suitably programmed binary input, or, by sending an appropriate command over the data communications
channel(s).
Indication LEDs
Relays have either 8 or 16 user programmable LED indicators. Each LED can be programmed to be illuminated
as either green, yellow or red. Where an LED is programmed to be lit both red and green it will illuminate yellow. .
Each LED can be assigned two different colours dependent upon whether a Start/Pickup or Operate condition
©2010 Siemens Protection Devices Limited Chapter 1 Page 15 of 52