Current Inputs; Binary Inputs; Figure 3-12 Binary Input Logic - Siemens 7SR45 Argus User Manual

3.10 Current Inputs

The 7SR45 Argus Relay consists of 4 current inputs. The 3 current inputs are provided for measuring the phase
currents and 1 current input is provided for measuring the ground current.
Based on the ordering option, current inputs are available for 1A and 5A variants.
The 7SR45 Argus Relay consists of 1 built-in Power Current Transformer (PCT) and 1 built-in Measuring Current
Transformer (MCT) for each phase current input. 1 MCT is provided on the ground-current input.
The current is sampled at 800Hz for both 50 Hz and 60 Hz system frequency. Protection and monitoring functions
of the relay use the fundamental frequency component to calculate the RMS value of current.
The primary CT ratio used for the relay instruments and fault logs can be set in the CT/VT configuration menu.

3.11 Binary Inputs

The binary inputs (BI) are opto-couplers operated from a suitably rated AC/DC power supply.
The device variants with binary inputs having an 88V threshold can be operated using an AC/DC source and the
19 V threshold can be operated with DC source only.
The status of BI can be viewed via LCD or Reydisp Evolution software or SCADA.
The 7SR45 Argus Relays are available with 2 or 4 binary inputs. The user can assign any binary input to any of
the available functions such as inhibits, binary outputs, reset flags, and general alarms (INPUT CONFIG > INPUT
MATRIX). Binary input can also be mapped to operate the pulse output in the presence of auxiliary power
supply/CT input.
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 (For example, cross
site wiring). The default pick-up time of 20 ms provides AC immunity. Each input can be configured
independently.
Each input can be logically inverted to facilitate integration of the relay within the user scheme. When inverted the
relay indicates that the BI is triggered when no binary input voltage is applied. Inversion occurs before the PU &
DO time delay.
Binary inputs can be configured for instantaneous operation from 19 V DC power supply by setting of
0 ms PU and 25 ms DO timers.
Each binary input can be assigned to any binary output. This allows the relay to provide panel indications and
alarms.
Inverted Inputs
BI 1 inverted
Binary Input 1
INPUT
CONFIG>
BINARY
INPUT
CONFIG
BI n inverted
Binary Input n
©2018 Siemens Protection Devices Limited
BI 1 P/U Delay
=1
BI n P/U Delay
=1
Figure 3-12 Binary Input Logic
Chapter 1 - 7SR45 Description of Operation
BI 1 D/O Delay
BI 1
Event
BI n D/O Delay
BI n
Event
Chapter 1 Page 37 of 48
INPUT CONFIG>
INPUT MATRIX
(OR gates)
Logic signals,
e.g. 'Inhibit 51-1'