Current Inputs; Voltage Input; Binary Inputs; Figure 2-2 Binary Input Logic - Siemens 7SR242 Duobias Technical Manual

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.
2.8

Binary inputs

The binary inputs are opto-couplers operated from a suitably rated dc supply.
Relays are fitted with 9 or 19 binary inputs (BI). The user can assign any binary input to any of the available
functions (INPUT CONFIG > INPUT MATRIX).
The Power Supply module includes the relay basic I/O. The module includes 3 x BI.
Pick-up (PU) and drop-off (DO) time delays are associated with each binary input. Where no pick-up time delay
has been applied the input may pick up due to induced ac voltage on the wiring connections (e.g. cross site
wiring). The default pick-up time of 20ms provides ac immunity. Each input can be programmed independently.
Each input may be logically inverted to facilitate integration of the relay within the user scheme. When inverted the
relay indicates that the BI is energised when no d.c. is applied. Inversion occurs before the PU & DO time delay,
see fig. 2.8-1.
Each input may be mapped to any front Fascia indication LED and/or to any Binary output contact and can also
be used with the internal user programmable logic. This allows the relay to provide panel indications and alarms.
©2015 Siemens Protection Devices Limited
Chapter 1) 7SR242 Duobias Description Of Operation
Figure 2-2 Binary Input Logic
Chapter 1 Page 19 of 60