Siemens Reyrolle 7SR23 DAD High-Impedance Differential Protection Relay

Siemens Reyrolle 7SR23 DAD High-Impedance Differential Protection Relay Suppliers,Exporters in India

ARP IMPEX supplies and exports Siemens Reyrolle 7SR23 DAD High-Impedance Differential Protection Relays for busbar protection panels, transformer protection systems, industrial substations and electrical distribution projects. Buyers can share the complete Siemens article number, CT details, protection scheme and destination country for price and availability.

The Siemens Reyrolle 7SR23 is a numerical high-impedance circulating-current relay used to detect phase and earth faults within a defined protection zone. It is commonly applied to busbars, transformer windings, autotransformers, reactors, motors and electrical connections where fast and selective fault clearance is required.

The relay has four current inputs and can be configured for three-phase high-impedance differential protection, restricted earth-fault protection or measured earth-fault protection. Integral CT supervision monitors the CT secondary wiring and can raise an alarm if it detects an open circuit or abnormal current imbalance.

The 7SR23 also provides trip-circuit supervision, programmable logic, fault recording, event recording and waveform recording. Front USB and rear RS485 communication are provided as standard, while selected versions support Ethernet and IEC 61850 communication for substation automation projects.

Buyers looking for a Siemens Reyrolle 7SR23 supplier in India, a high-impedance busbar protection relay exporter, or a restricted earth-fault relay for transformer protection can send the exact ordering code and project specification for quotation.

Technical Specifications

• Brand: Siemens
• Product family: Reyrolle
• Series: 7SR23 DAD
• Product type: Numerical high-impedance differential protection relay
• Operating principle: High-impedance circulating-current protection
• Current inputs: Four
• CT secondary rating: 1 A or 5 A
• Rated frequency: 50/60 Hz
• Main protection functions: Three-phase differential, restricted earth fault and measured earth fault
• CT supervision: Three-phase CT secondary circuit supervision
• Trip-circuit supervision: Available
• Binary inputs: Nine or nineteen, depending on the selected configuration
• Binary outputs: Eight or sixteen, depending on the selected configuration
• Auxiliary supply: 24–250 V DC or 100–230 V AC
• Housing options: Size E6 or E8
• Construction: 4U-high withdrawable design
• Display: Four-line backlit LCD
• Indication: Fixed LEDs with eight or sixteen programmable tri-colour LEDs, depending on the version
• Local communication: Front USB port
• Remote communication: Rear RS485 port
• Optional communication: Electrical Ethernet, optical Ethernet and fibre-optic ports
• Communication protocols: IEC 60870-5-103, Modbus RTU and DNP3
• IEC 61850: Available on selected Ethernet configurations
• Configuration software: Siemens Reydisp Evolution and Reydisp Manager
• Data recording: Fault, event and waveform records
• Logic: User-programmable protection and control logic

The exact binary I/O, housing size, communication ports and protocol options depend on the complete Siemens ordering code. Siemens currently lists active 7SR23 configurations with four CT inputs, 1/5 A measurement, wide-range auxiliary supply and IEC 61850 communication options.

Main Protection Functions

Depending on the selected configuration, the Siemens Reyrolle 7SR23 can provide:

• Three-phase high-impedance differential protection
• High-impedance restricted earth-fault protection
• Instantaneous and definite-time measured earth-fault protection
• CT secondary circuit supervision
• Trip-circuit supervision
• Protection lockout
• Programmable trip and alarm logic
• Primary and secondary differential-current measurement
• Binary input and output status monitoring
• Fault, event and disturbance recording

The relay can be configured for arrangements such as three-pole differential plus restricted earth fault, three-pole differential plus measured earth fault, or two separate restricted earth-fault zones.

High-Impedance Differential Protection

The 7SR23 is used where the protection scheme must remain stable during faults outside the protected zone while operating quickly for faults within that zone.

A high-impedance scheme normally uses matched protection CTs along with external stabilising resistors and non-linear voltage-limiting resistors. Siemens recommends low-reactance CTs suitable for high-impedance protection, such as IEC 61869-2 Class PX CTs.

These external components form part of the complete protection arrangement and must be selected according to the CT ratio, CT resistance, lead resistance, maximum fault current and required operating level. An optional high-impedance component box can house the stabilising and voltage-limiting resistors outside the main relay compartment.

Features

• Provides phase and earth-fault protection within a defined electrical zone
• Suitable for high-speed busbar and equipment protection
• Four current inputs cover three-phase and earth-fault measurements
• Supports 1 A and 5 A CT secondary circuits
• Can be configured for differential or restricted earth-fault duties
• CT supervision monitors secondary wiring for open circuits and imbalance
• Trip-circuit supervision checks the breaker trip wiring
• Programmable logic supports different protection and interlocking arrangements
• Multiple binary input and output configurations are available
• Wide-range auxiliary supply suits common substation DC and AC systems
• Front LCD provides access to measurements, settings and fault information
• Programmable LEDs give clear local trip and alarm indication
• Front USB simplifies commissioning and settings transfer
• The rear RS485 supports remote access and SCADA communication
• Ethernet and IEC 61850 options suit modern substation projects
• Fault, event and waveform records support post-trip analysis
• Withdrawable construction simplifies relay testing and replacement
• E6 and E8 housing options suit different panel I/O requirements
• Optional component boxes help manage stabilising and non-linear resistors

The relay has an operating time of less than one cycle under the stated Siemens test condition of five times the setting current. Actual protection performance depends on the scheme design, CTs, relay settings and external components.

Applications

Siemens Reyrolle 7SR23 High-Impedance Differential Relays are commonly used for:

• Medium-voltage busbar protection
• High-voltage busbar protection
• Single-zone and sectionalised busbars
• Transformer winding restricted earth-fault protection
• Two-winding transformer protection schemes
• Autotransformer protection
• Reactor protection
• Large motor differential protection
• Generator connection protection
• Cable and bus-section connections
• Industrial switchgear panels
• Utility distribution substations
• Power-generation plants
• Solar and wind power substations
• Oil and gas electrical systems
• Refinery and petrochemical substations
• Steel and cement plant power systems
• Mining and mineral-processing facilities
• Water and wastewater plants
• Protection-panel retrofit projects
• Replacement of older high-impedance protection relays

The 7SR23 is suitable for buyers requiring a numerical high-impedance busbar protection relay, a transformer restricted earth-fault relay with IEC 61850, or a four-current-input differential protection relay for industrial substations.

Selecting the Correct Siemens 7SR23 Relay

The Reyrolle 7SR23 should not be selected only by the series name. The relay configuration and external components must match the complete high-impedance protection scheme.

For accurate selection and quotation, provide:

• Complete Siemens MLFB or article number
• Busbar, transformer, reactor or motor application
• Three-phase differential or restricted earth-fault requirement
• Number of protection zones
• System voltage
• CT ratio and secondary rating
• CT class, knee-point voltage and winding resistance
• CT lead length and lead resistance
• Maximum through-fault current
• Required relay operating current
• Auxiliary supply voltage
• Number of binary inputs and outputs
• Trip-circuit supervision requirement
• RS485 or IEC 61850 communication requirement
• Electrical or optical Ethernet preference
• E6 or E8 housing requirement
• Stabilising resistor and non-linear resistor requirements
• Quantity and destination country

For replacement enquiries, share a clear photograph of the existing relay nameplate, full Siemens article number, protection diagram, CT details and existing stabilising-resistor information.

Siemens Reyrolle 7SR23 Supplier and Exporter in India

ARP IMPEX is an independent supplier and exporter of Siemens Reyrolle protection relays in India. We supply Reyrolle 7SR23 High-Impedance Differential Protection Relays for utilities, EPC contractors, switchgear manufacturers, protection-panel builders and industrial maintenance companies.

We handle enquiries for:

• Siemens Reyrolle 7SR23 busbar protection relays
• High-impedance differential relays
• Transformer restricted earth-fault relays
• Numerical busbar protection relays with IEC 61850
• High-impedance protection component boxes
• Reyrolle relay replacement requirements
• Industrial and utility substation projects

The Siemens 7SR23 price depends on the complete article number, binary I/O arrangement, housing size, communication option and external resistor requirement. Quotations should therefore be based on the exact ordering code and protection specification.

For price and export availability, send the complete Siemens part number, CT details, protection scheme, required quantity and delivery country.