Siemens 7SR224 Description & Operation page 12

(1) Description of Operation 7SR224
The fascia is an integral part of the relay. Handles are located at each side of the relay which allow it
to be withdrawn from the relay case.
Relay Information
Above the LCD three labels are provided, these provide the following information:
1) Product name and order code.
2) Nominal current rating, rated frequency, voltage rating, auxiliary dc supply rating, binary
input supply rating, configuration and serial number.
3) Blank label for user defined information.
A 'template' is available to allow users to create and print customised labels.
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.
Functions are assigned to the LEDs in the OUTPUT CONFIG>OUTPUT MATRIX menu.
Each LED can be labelled by withdrawing the relay and inserting a label strip into the pocket behind
the front fascia. A 'template' is available to allow users to create and print customised legends.
Page 12 of 66 ©2009 Siemens Protection Devices Limited