ABB RET615 Transformer Protection and Control Relay

ABB RET615 Transformer Protection and Control Relay Suppliers,Exporters in India

ARP IMPEX supplies and exports ABB RET615 transformer protection and control relays from India for substations, medium-voltage switchgear, power plants, transformer panels and industrial distribution systems. We accept enquiries for new projects, plant maintenance, matching replacements and relay upgrade requirements.

ABB Relion RET615 is made for the protection of two-winding power transformers, unit transformers, step-up transformers and generator-transformer blocks. It brings transformer differential protection, restricted earth-fault protection, overcurrent backup, thermal protection, circuit-breaker control, measurement and fault recording into one relay.

The relay is available in several standard configurations. The main difference between them is:

• Whether restricted earth-fault protection is required on the HV or LV side
• Whether low-impedance or high-impedance REF protection is used
• Whether voltage protection and voltage measurement are required

For an accurate ABB RET615 transformer differential relay price, buyers should share the full order code or a clear photograph of the relay nameplate. “RET615” alone does not confirm the standard configuration, auxiliary supply, input arrangement, communication card or RTD module.

ABB RET615 Models and Standard Configurations

The IEC version of RET615 comes in eight standard configurations: A, B, C, D, E, F, G and H. These are different application configurations of the same relay family, not separate model numbers. The logic and signal connections can be adjusted through ABB PCM600 according to the transformer protection scheme.

ABB RET615 Standard Configuration A

Configuration A provides transformer differential protection with low-impedance restricted earth-fault protection on the HV side.

It is normally selected for transformers with an earthed HV-side neutral where numerical low-impedance REF protection is required.

Protection functions cover:

• Stabilised transformer differential protection
• Instantaneous transformer differential protection
• Low-impedance restricted earth-fault protection on the HV side
• Overcurrent protection on the HV and LV sides
• Earth-fault backup protection
• Negative-sequence overcurrent protection
• Transformer thermal overload protection
• Circuit-breaker failure protection
• Optional arc-flash protection

Configuration A also supports an optional module with six RTD and two mA inputs.

ABB RET615 Standard Configuration B

Configuration B provides transformer differential protection with low-impedance restricted earth-fault protection on the LV side.

This configuration is used where the transformer has a solidly earthed LV-side neutral or an LV neutral connected through a neutral earthing resistor. It also suits certain schemes with a separate earthing transformer inside the protected zone.

Available protection functions include:

• Transformer differential protection
• Low-impedance restricted earth-fault protection on the LV side
• HV- and LV-side overcurrent protection
• HV- and LV-side earth-fault backup protection
• Negative-sequence current protection
• Transformer thermal overload protection
• Circuit-breaker failure protection
• Optional arc detection

An optional six-RTD and two-mA module is available for temperature and analogue signal monitoring.

ABB RET615 Standard Configuration C

Configuration C provides transformer differential protection with high-impedance restricted earth-fault protection on the HV side.

This version is considered where the protection design uses a conventional high-impedance REF scheme. The neutral and phase current transformers used for the REF arrangement must have matching ratios.

Protection functions cover:

• Stabilised and instantaneous transformer differential protection
• High-impedance restricted earth-fault protection on the HV side
• Overcurrent protection on both transformer sides
• Non-directional earth-fault backup protection
• Negative-sequence overcurrent protection
• Thermal overload protection
• Circuit-breaker failure protection
• Optional three-channel arc-flash protection

Configuration C can also be supplied with six RTD and two mA inputs.

ABB RET615 Standard Configuration D

Configuration D combines transformer differential protection with high-impedance restricted earth-fault protection on the LV side.

It is mainly selected for transformers with a solidly earthed or resistance-earthed LV neutral where a high-impedance REF scheme is already specified.

The configuration provides:

• Transformer differential protection
• High-impedance REF protection on the LV side
• Phase overcurrent protection on the HV and LV sides
• Earth-fault backup protection
• Negative-sequence protection
• Transformer thermal overload protection
• Breaker failure protection
• Optional arc-flash detection

Six RTD inputs and two mA inputs are available through the optional analogue module.

ABB RET615 Standard Configuration E

Configuration E provides transformer differential protection, voltage protection and measurement, with low-impedance REF protection on the HV side.

It is selected when the transformer panel requires current-based protection along with phase-voltage and residual-voltage supervision.

Available functions include:

• Transformer differential protection
• Low-impedance REF protection on the HV side
• HV- and LV-side overcurrent protection
• Earth-fault backup protection
• Transformer thermal overload protection
• Overvoltage protection
• Undervoltage protection
• Residual overvoltage protection
• Fuse-failure supervision
• Current, voltage, power and energy measurement
• Circuit-breaker failure protection
• Optional arc-flash protection

Configuration E has an optional module with two RTD inputs and one mA input.

ABB RET615 Standard Configuration F

Configuration F provides transformer differential and voltage protection with low-impedance REF protection on the LV side.

This version is suitable where the transformer has an earthed LV neutral, and the panel also requires voltage supervision and electrical measurements.

The configuration covers:

• Stabilised and instantaneous transformer differential protection
• Low-impedance REF protection on the LV side
• Overcurrent and earth-fault backup protection
• Negative-sequence current protection
• Transformer thermal overload protection
• Overvoltage and undervoltage protection
• Residual overvoltage protection
• Fuse-failure supervision
• Current, voltage, power, frequency and energy measurement
• Circuit-breaker failure protection
• Optional arc detection

Two RTD inputs and one mA input are available as an option.

ABB RET615 Standard Configuration G

Configuration G combines transformer differential and voltage functions with high-impedance REF protection on the HV side.

It is used where the protection scheme requires high-impedance restricted earth-fault protection at the transformer HV neutral and voltage inputs are also required.

Protection and measurement functions cover:

• Transformer differential protection
• High-impedance REF protection on the HV side
• Overcurrent protection on both sides
• Earth-fault backup protection
• Negative-sequence current protection
• Transformer thermal protection
• Overvoltage and undervoltage protection
• Residual overvoltage protection
• Fuse-failure supervision
• Power and energy measurement
• Circuit-breaker failure protection
• Optional arc-flash protection

The optional analogue module provides two RTD inputs and one mA input.

ABB RET615 Standard Configuration H

Configuration H provides transformer differential and voltage protection with high-impedance REF protection on the LV side.

It is normally selected where an LV-side high-impedance REF scheme is required along with voltage measurement and voltage protection.

The configuration provides:

• Stabilised and instantaneous transformer differential protection
• High-impedance REF protection on the LV side
• HV- and LV-side overcurrent protection
• Earth-fault backup protection
• Negative-sequence protection
• Thermal overload protection
• Overvoltage and undervoltage protection
• Residual overvoltage protection
• Fuse-failure supervision
• Power, energy and frequency measurement
• Circuit-breaker failure protection
• Optional arc-flash protection

Configuration H supports an optional two-RTD and one-mA input module.

Quick Selection of RET615 Configuration

• Configuration A: Low-impedance REF on HV side
• Configuration B: Low-impedance REF on LV side
• Configuration C: High-impedance REF on HV side
• Configuration D: High-impedance REF on LV side
• Configuration E: Low-impedance REF on HV side with voltage functions
• Configuration F: Low-impedance REF on LV side with voltage functions
• Configuration G: High-impedance REF on HV side with voltage functions
• Configuration H: High-impedance REF on LV side with voltage functions
• Configurations A, C, E and G suit applications with an earthed HV-side neutral. Configurations B, D, F and H suit solidly earthed or resistance-earthed LV-side neutral arrangements.

ABB RET615 Transformer Protection Functions

Transformer Differential Protection

RET615 provides stabilised and instantaneous differential protection for two-winding transformers.

The differential element compares current entering and leaving the protected transformer zone. It is used for fast detection of internal faults such as:

• Phase-to-phase winding faults
• Internal short circuits
• Winding interturn faults
• Transformer bushing flashover
• Faults within the CT-defined protection zone

The relay uses second-harmonic restraint and waveform-based blocking to remain stable during transformer energisation. Fifth-harmonic restraint supports stability during moderate transformer overexcitation.

Restricted Earth-Fault Protection

RET615 provides either numerical low-impedance or conventional high-impedance restricted earth-fault protection, depending on the selected configuration.

REF protection is used for sensitive detection of earth faults close to the transformer neutral. These faults may not produce enough differential current for the main differential element to operate quickly.

The correct RET615 configuration depends on:

• Whether REF is required on the HV or LV winding
• Neutral earthing arrangement
• Neutral CT ratio
• Phase CT ratios
• Low- or high-impedance protection philosophy
• Existing stabilising resistor and voltage-dependent resistor arrangement

For an ABB RET615 restricted earth-fault relay quotation, share the transformer single-line diagram and CT details from both transformer sides.

Overcurrent and Earth-Fault Backup Protection

Separate protection stages are available for the HV and LV sides of the transformer.

Available functions include:

• Low-set overcurrent protection
• High-set overcurrent protection
• Instantaneous overcurrent protection
• Non-directional earth-fault protection
• Negative-sequence overcurrent protection
• Circuit-breaker failure protection

These functions provide backup protection for external faults and transformer faults not cleared by the main protection.

Transformer Thermal Overload Protection

RET615 calculates the thermal stress on the transformer windings. The function can provide an alarm or trip before prolonged overload causes excessive insulation ageing.

Temperature measurement from optional RTD inputs can be used alongside the calculated thermal protection. The inputs may be connected to oil-temperature, winding-temperature or ambient-temperature sensors, depending on the transformer arrangement.

Voltage Protection

Configurations E, F, G and H provide voltage protection and voltage measurement.

Available voltage functions include:

• Two-stage three-phase undervoltage protection
• Two-stage three-phase overvoltage protection
• Residual overvoltage protection
• Fuse-failure supervision
• Phase-voltage measurement
• Residual-voltage measurement
• Power and energy measurement

These configurations are useful when the transformer panel requires voltage supervision without installing a separate voltage protection relay.

Arc-Flash Protection

RET615 can be ordered with three arc-light sensor channels. The sensors may be fitted in the circuit-breaker, busbar and cable compartments of metal-enclosed switchgear.

An optional high-speed output module reduces the relay’s output operating time by approximately 4–6 milliseconds compared with normal power outputs. The arc sensor and high-speed output options must be included in the order code.

RTD and mA Inputs

Two optional analogue input arrangements are available.

For Configurations A, B, C and D:

• Six RTD inputs
• Two mA inputs

For Configurations E, F, G and H:

• Two RTD inputs
• One mA input

These inputs may be used for:

• Transformer top-oil temperature
• Transformer bottom-oil temperature
• Winding-temperature indication
• Ambient-temperature measurement
• Dry-type transformer temperature protection
• On-load tap-changer position
• Other analogue measurements through suitable transmitters

The available RTD module must be checked from the complete order code.

Control, Monitoring and Recording

RET615 also handles control and supervision work inside the transformer protection panel.

Available functions include:

• Circuit-breaker opening and closing
• Circuit-breaker position indication
• Disconnector control and indication
• Earthing-switch control and indication
• Tap-position indication
• Circuit-breaker condition monitoring
• Trip-circuit supervision
• Fuse-failure supervision in voltage configurations
• Relay self-supervision
• Fault recording
• Event recording
• Disturbance recording
• Load-profile recording
• Local and remote operation
• Programmable alarm indications
• Web HMI access

The protection logic, binary inputs, outputs, interlocking and communication signals are configured through ABB PCM600.

Technical Specifications

• Brand: ABB
• Product family: Relion 615 Series
• Model: RET615
• Product type: Transformer protection and control relay
• Main application: Two-winding power transformer protection
• Transformer applications: Unit transformers, step-up transformers and generator-transformer blocks
• IEC standard configurations: A, B, C, D, E, F, G and H
• Rated frequency: 50/60 Hz
• Current inputs: Six phase-current inputs and one neutral-current input
• Current input rating: Selectable 1 A or 5 A
• Voltage inputs: Three phase-voltage inputs and one residual-voltage input in Configurations E–H
• Voltage input rating: 60–210 V AC
• Binary inputs: Up to 14, depending on hardware
• Binary outputs: Up to four power outputs and nine signal outputs, depending on hardware
• High-speed outputs: Three with the selected HSO module
• RTD inputs: Up to six
• mA inputs: Up to two
• Binary input rated range: 24–250 V DC
• Binary input threshold: Adjustable from 16–176 V DC
• Auxiliary supply options: Wide-range AC/DC or low-range DC versions
• Operating temperature: –25°C to +55°C continuously
• Relative humidity: Below 93%, non-condensing
• Installation altitude: Up to 2,000 metres
• Front protection: IP54 when flush mounted
• Rear terminal protection: IP20
• Frame dimensions: Approximately 177 × 177 mm
• Overall depth: Approximately 201 mm
• Complete relay weight: Approximately 4.1 kg
• Configuration software: ABB PCM600
• Installation: Withdrawable plug-in relay unit

The actual analogue inputs, binary channels, RTD arrangement and auxiliary voltage depend on the complete RET615 ordering code.

ABB RET615 Communication Options

RET615 can communicate with SCADA, DCS and substation automation systems.

Communication options cover:

• IEC 61850 Edition 2
• IEC 61850 GOOSE messaging
• IEC 61850-9-2 LE process bus
• Modbus TCP/IP
• Modbus RTU and ASCII
• DNP3 TCP/IP
• DNP3 serial
• IEC 60870-5-103
• Copper Ethernet
• Fibre-optic Ethernet
• RS-232 and RS-485 serial interfaces
• PRP network redundancy
• HSR network redundancy
• RSTP Ethernet ring
• IEEE 1588 time synchronisation
• SNTP time synchronisation
• IRIG-B time synchronisation

Protocol and physical communication interface availability depends on the communication card fitted in the relay.

Features

• Dedicated protection for two-winding transformers
• Eight IEC standard configurations
• Stabilised and instantaneous transformer differential protection
• Low-impedance and high-impedance REF options
• HV-side and LV-side restricted earth-fault arrangements
• Separate overcurrent backup protection for both transformer sides
• Transformer thermal overload protection
• Voltage protection in Configurations E–H
• Optional RTD and mA inputs
• Optional three-channel arc-flash protection
• Optional high-speed tripping outputs
• Circuit-breaker control and supervision
• Disturbance, fault and event recording
• IEC 61850 and GOOSE communication
• Process-bus support in selected configurations
• Withdrawable plug-in relay construction
• Local HMI and Web HMI
• Logic and signal configuration through ABB PCM600
• Suitable for new transformer panels and matching replacement requirements

Applications

ABB RET615 transformer protection relays are used for:

• Two-winding power transformers
• Distribution transformers
• Unit transformers
• Step-up transformers
• Generator-transformer blocks
• Utility substations
• Industrial substations
• Captive power plants
• Transformer incomer panels
• Medium-voltage switchgear
• Transformer differential protection
• Restricted earth-fault protection
• Transformer overcurrent backup protection
• Transformer thermal overload protection
• Transformer voltage supervision
• Arc-flash-protected switchgear panels
• New transformer protection panels
• Existing RET615 replacement requirements

Typical users include power utilities, switchgear manufacturers, EPC contractors, panel builders, steel plants, cement plants, mines, refineries, petrochemical plants, water-treatment facilities, renewable power plants and large manufacturing units.

RET615 IEC and ANSI Versions

RET615 is available for both IEC and ANSI protection applications. The eight configurations described above apply to the IEC product version.

The ANSI version uses a different function structure and has two standard application configurations. Buyers should therefore mention RET615 IEC or RET615 ANSI when sending an enquiry.

ABB RET615 Replacement and REX615 Migration

ABB Library currently identifies RET615 IEC under the Classic lifecycle category. ABB also positions REX615 as the next-generation platform for its earlier 615 and 620 series relays. Exact RET615 availability may depend on the product version, order code and destination market.

For a matching ABB RET615 replacement relay, check:

• Complete RET615 order code
• IEC or ANSI version
• Standard configuration letter
• Product and firmware version
• HV- and LV-side CT ratings
• Neutral CT rating
• VT secondary voltage
• Low- or high-impedance REF arrangement
• Auxiliary supply voltage
• Binary input voltage
• Input and output module
• RTD and mA module
• Arc-protection option
• Communication card
• Communication protocol
• Existing PCM600 configuration
• IEC 61850 files
• Panel cut-out and terminal arrangement

Depending on the requirement and current availability, the offer may cover a matching RET615 relay or a properly configured ABB REX615 replacement.

Buyers looking for an ABB RET615 transformer differential protection relay supplier and exporter in India can contact us for pricing, availability, configuration checks, replacement requirements and export supply.