Current Inputs; Voltage Input - Siemens 7SR242 Manual

initiates operation. The LED illumination colour is assigned in the OUTPUT CONFIG>LED CONFIG menu for both
Pickup and Operate initiation.
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.
Each LED can be user programmed as hand or self–resetting. Hand reset LEDs 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).
The status of hand reset LEDs is maintained by a back up storage capacitor in the event of an interruption to the
d.c. supply voltage.
Standard Keys
The relay is supplied as standard with five pushbuttons. The buttons are used to navigate the menu structure and
control relay functions. They are labelled:
▲
▼
TEST/RESET►
ENTER
CANCEL.
NOTE: All settings and configuration of LEDs, BI, BO and function keys can be accessed and set by the user
using these keys. Alternatively configuration/settings files can be loaded into the relay using 'ReyDisp'.
2.6

Current Inputs

In total eight current inputs are provided on the Analogue Input modules. Terminals are available for both 1A and
5A inputs. CT ratios are input by the user in the CT/VT CONFIG menu.
Current is sampled at 1600Hz for 50Hz systems and 1920Hz for 60Hz systems (32 samples per cycle).
The waveform recorder samples and displays current input waveforms at 32 samples per cycle.
2.7

Voltage Input

An optional voltage input is provided on the Analogue Input module 'A'.
VT ratios are input by the user in the CT/VT CONFIG menu.
Voltage is sampled at 1600Hz for 50Hz systems and 1920Hz for 60Hz systems (32 samples per cycle).
The waveform recorder displays the voltage input waveform at 32 samples per cycle.
©2010 Siemens Protection Devices Limited
Increases a setting or moves up menu.
Decreases a setting or moves down menu.
Moves right, can be used to reset selected functionality and for LED test (at
relay identifier screen).
Used to initiate and accept settings changes.
Used to cancel settings changes and/or move up the menu structure by one
level per press.
7SR242 Duobias Description Of Operation
Chapter 1 Page 16 of 52