High Impedance Protection Relay Block 7SR23 With (0NO+2NC)

Features and technical specifications:
1. Motor Protection
2. CT inputs : 4 No’s
3. Binary inputs : 9 No
4. Binary output’s : 8 NO
5. RS232 Communication Port

Relay Function :-
1 Not Connected
2 Receive Data (RXD)
3 Transmit Data (TXD)                                                                                                
4 Output Supply +5V 50mA
5 Signal Ground (GND)
6 Output Supply +5V 50mA
7 Linked to 8 (volts free)
8 Linked to 7 (volts free)
9 Output Supply +5V 50mA

1. Current Inputs:-
Four current inputs are provided on the Analogue Input module. Terminals are available for both 1A and 5A inputs. Analogue waveform processing is optimised to provide high security operation. 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. Binary inputs :-
The binary inputs are isolated with opto-couplers and can be operated from a suitably rated dc supply. Relays are fitted with 9 or 19 binary inputs (BI). 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, 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.

2. Binary Outputs (Output Relays) :-
Relays are fitted with 8 or 16 binary outputs. All outputs are fully user configurable and can be programmed to
operate from any or all of the available functions. The Power Supply module includes the relay basic I/O. The module includes six binary outputs each fitted with 1 contact – providing in total 1 x normally closed (NC), 2 x change-over (CO) and 3 x normally open (NO) contacts. In the default mode of operation binary outputs are self reset and remain energised for a user configurable minimum operate time of up to 60 seconds. If required, outputs can be programmed to operate as ‘hand reset’ or ‘pulsed’. Where an output is programmed to be ‘hand reset’ and ‘pulsed’ then the output will be ‘hand reset’ only. The binary outputs can be used to operate the trip coils of the circuit breaker directly where the trip coil current does not exceed the ‘make and carry’ contact rating. The circuit breaker auxiliary contacts or other in-series auxiliary device must be used to break the trip coil current. CB’Trip Contacts’ are assigned in the OUTPUT CONFIG>BINARY OUTPUT CONFIG menu. Operation of a ‘Trip Contact’ will actuate the ‘Trip Alert’ screen where enabled and will initiate both fault record storage and CB Fail protection where enabled. When the relay is withdrawn from the case all normally closed contacts will be open circuited. This should be considered in the design of the control and protection circuitry.