Siemens Reyrolle 7SR45 Self-Powered Overcurrent and Earth-Fault Protection Relay

Siemens Reyrolle 7SR45 Self-Powered Overcurrent and Earth-Fault Protection Relay Suppliers,Exporters in India

ARP IMPEX is a supplier and exporter of Siemens Reyrolle 7SR45 Self-Powered and Dual-Powered Overcurrent Protection Relays in India. We supply these relays for ring main units, compact substations, medium-voltage feeders, transformer panels and industrial switchgear projects.

The Siemens Reyrolle 7SR45 is a numerical protection relay used for non-directional phase overcurrent and earth-fault protection. It is mainly selected for installations where a permanent auxiliary power supply is not available or cannot be fully relied upon.

Self-powered models draw the energy required for protection from the connected current transformers. Dual-powered models can work from an external AC or DC supply during normal operation and continue their basic protection duty from the CT circuit if the auxiliary supply fails.

This makes the 7SR45 suitable for remote substations, RMU panels and secondary distribution systems where installing and maintaining a separate station battery may not be practical.

The relay provides phase overcurrent, earth-fault and thermal overload protection. It also includes a capacitor-discharge pulse output for operating a compatible low-energy circuit-breaker trip coil. The relay, CTs and breaker trip mechanism must therefore be selected as one complete protection arrangement.

Different 7SR45 versions are available with varying CT ratings, auxiliary supply options, binary contacts, trip indications and communication facilities. Buyers can send the complete Siemens article number, CT details and breaker trip-coil information for price and export availability.

Technical Specifications

• Brand: Siemens
• Product family: Reyrolle Argus
• Series: 7SR45
• Product type: Numerical overcurrent and earth-fault protection relay
• Protection direction: Non-directional
• Available versions: Self-powered and dual-powered
• Main application: Secondary distribution and medium-voltage feeder protection
• Current inputs: Four CT inputs
• CT secondary options: 1 A or 5 A, depending on the model
• Rated frequency: 50/60 Hz
• Protection functions: Phase overcurrent, earth fault and thermal overload
• Protection curves: Definite-time, IEC and ANSI inverse-time characteristics
• Trip arrangement: Capacitor-discharge pulse output for a compatible low-energy trip coil
• Auxiliary supply: Available on dual-powered versions
• Setting groups: Two
• Display: Front LCD
• Indication: Fixed and programmable LEDs
• Trip indication: Local or remote trip flag, depending on the version
• Local communication: Front USB port
• Remote communication: RS485 on applicable models
• Communication protocols: IEC 60870-5-103 and Modbus RTU
• Configuration software: Siemens Reydisp Evolution
• Mounting: Flush mounting in switchgear and protection panels

The exact CT rating, auxiliary voltage, binary contacts and communication arrangement depend on the complete Siemens ordering code.

Main Protection Functions

Depending on the selected model, the Siemens Reyrolle 7SR45 can provide:

• Instantaneous phase overcurrent protection
• Time-delayed phase overcurrent protection
• Measured or calculated earth-fault protection
• Thermal overload protection
• Switch-onto-fault protection
• Transformer inrush detection
• Protection lockout
• Relay and trip-circuit supervision
• Configurable alarm and output logic

Definite-time and inverse-time protection curves allow the 7SR45 to coordinate with upstream and downstream circuit breakers, fuses and protection relays.

Features

• Can protect without depending completely on an external auxiliary supply
• Self-powered and dual-powered versions are available
• Suitable for ring main units and compact MV switchgear
• Combines phase overcurrent and earth-fault protection in one relay
• Thermal overload protection helps identify prolonged feeder loading
• IEC and ANSI curves support protection coordination
• The switch-onto-fault function helps clear an existing fault after the breaker closes
• Inrush detection helps avoid unwanted trips during transformer energisation
• Pulse trip output works with a compatible low-energy breaker trip coil
• Two setting groups suit different network operating conditions
• LCD provides access to measurements, settings and trip information
• Programmable LEDs give a clear local alarm and protection indication
• Trip-flag options help identify the relay operation after a fault
• Front USB simplifies settings transfer and commissioning
• RS485 communication is available for remote monitoring
• Fault and event records assist maintenance after a trip
• Compact construction suits new panels and retrofit projects
• Suitable for the replacement of older self-powered protection relays

Applications

Siemens Reyrolle 7SR45 Protection Relays are commonly used for:

• Ring main units
• Secondary distribution substations
• Medium-voltage incoming feeders
• Medium-voltage outgoing feeders
• Compact switchgear panels
• Distribution transformer protection
• Transformer backup protection
• Cable feeder protection
• Radial distribution networks
• Remote electrical substations
• Utility distribution systems
• Industrial power-distribution panels
• Solar and renewable-energy substations
• Water and wastewater pumping stations
• Mining and quarry substations
• Oil and gas electrical systems
• Railway and infrastructure power networks
• Switchgear retrofit projects
• Replacement of older CT-powered relays

The range is suitable for buyers searching for a self-powered overcurrent relay for RMU panels, a CT-powered earth-fault protection relay, or a dual-powered relay for remote medium-voltage substations.

Selecting the Correct Siemens 7SR45 Relay

The term “Siemens 7SR45 relay” does not identify one standard configuration. Models differ by CT rating, auxiliary supply, binary contacts, communication and trip-indication arrangement.

For an accurate quotation, share:

• Complete Siemens article number
• Self-powered or dual-powered requirement
• CT ratio and CT secondary rating
• Feeder or transformer application
• Auxiliary supply voltage, where applicable
• Circuit-breaker make and model
• Low-energy trip-coil details
• Local or remote trip-flag requirement
• RS485 communication requirement
• Required quantity
• Delivery country

For replacement enquiries, share clear photographs of the relay nameplate and terminal arrangement. The existing circuit diagram and breaker trip-coil details can also help confirm the correct replacement.

Siemens Reyrolle 7SR45 Supplier and Exporter in India

ARP IMPEX supplies Siemens Reyrolle 7SR45 Self-Powered and Dual-Powered Protection Relays for switchgear manufacturers, panel builders, EPC contractors, utilities and industrial maintenance companies.

We handle enquiries for:

• Siemens Reyrolle 7SR45 self-powered relays
• Siemens 7SR45 dual-powered relays
• Overcurrent and earth-fault protection relays
• CT-powered relays for RMU panels
• Protection relays for remote substations
• Transformer feeder protection relays
• Relays with capacitor-discharge trip outputs
• 7SR45 relays with RS485 communication
• Replacement self-powered protection relays
• Medium-voltage switchgear retrofit requirements

The Siemens Reyrolle 7SR45 price depends on the exact article number, CT input, auxiliary supply, communication and trip arrangement.

Send the complete Siemens part number, application details, quantity and destination country for price, availability and export quotation.