ABB RET620 Transformer Protection Relay

ABB RET620 Transformer Protection Relay Suppliers,Exporters in India

ARP IMPEX supplies and exports ABB RET620 transformer protection and control relays from India for utility substations, transformer panels, power plants, EPC projects and industrial power distribution systems. We handle enquiries for new projects, existing relay replacement, switchgear extensions and plant maintenance requirements.

ABB Relion RET620 is mainly used for the protection and control of two-winding power transformers. It is also used with step-up transformers and generator-transformer blocks in utility and industrial power systems. The relay combines transformer protection, breaker control, measurement, fault recording and communication in one unit.

The main protection functions cover transformer differential protection, restricted earth-fault protection, overcurrent backup, thermal overload and overexcitation protection. RET620 can also be ordered with automatic voltage regulation for transformers fitted with an on-load tap changer.

This relay is normally selected where the transformer panel requires more input and output points, breaker control or voltage regulation functions than a basic transformer protection relay. It is suitable for new transformer panels as well as matching spare and replacement requirements.

Buyers looking for an ABB RET620 transformer protection relay supplier in India should share the complete order code or a clear relay nameplate. The model name alone does not confirm the auxiliary supply, communication card, input arrangement or optional functions.

ABB RET620 Models and Available Options

ABB RET620 is a configurable transformer protection relay, not a family containing several separate model numbers.

ABB RET620 IEC

The IEC version is mainly used for two-winding power transformers, step-up transformers and generator-transformer applications.

It is supplied with a default application configuration that can be adjusted through ABB PCM600 according to the transformer rating, CT arrangement, protection requirement and switchgear scheme.

ABB RET620 ANSI

The ANSI version follows a different ordering and protection structure. It is available for two-winding and three-winding transformer applications.

Buyers should clearly mention whether they require ABB RET620 IEC or RET620 ANSI when sending an enquiry. The order codes and function arrangements are not the same.

ABB RET620 Automatic Voltage Regulator Option

RET620 can be ordered with automatic voltage regulation for transformers fitted with a motor-operated on-load tap changer.

This option is used for:

• Automatic transformer voltage control
• Manual tap raise and lower commands
• Tap-position monitoring
• Single-transformer operation
• Parallel transformer operation
• Circulating-current compensation
• ABB RET620 Arc-Protection Option

An optional arc-protection arrangement is available for monitoring switchgear compartments.

Arc sensors can be fitted in the:

• Circuit-breaker compartment
• Busbar compartment
• Cable termination compartment

ABB RET620 Input and Output Options

Depending on the project, RET620 can be ordered with:

• Additional binary inputs
• Additional binary outputs
• RTD inputs
• mA inputs
• High-speed trip outputs
• Copper Ethernet communication
• Fibre-optic Ethernet communication
• Serial communication

ABB lists arc protection and automatic voltage regulation among the optional functions for RET620. The actual relay hardware depends on the ordered configuration.

Technical Specifications

• Brand: ABB
• Product family: Relion 620 Series
• Model: RET620
• Product type: Transformer protection and control relay
• Main application: Two-winding power transformer protection
• Other applications: Step-up transformers and generator-transformer blocks
• Available versions: IEC and ANSI
• Main IEC configuration: Conventional CT and VT input version
• Phase-current inputs: Six
• Residual-current inputs: Two
• CT secondary rating: 1 A or 5 A
• Phase-voltage inputs: Three
• Residual-voltage input: One
• Additional voltage inputs: Available for synchronism check and voltage regulation
• Voltage input range: 60–210 V AC
• Rated frequency: 50/60 Hz
• Binary inputs and outputs: Depend on the selected hardware module
• RTD inputs: Available for transformer temperature monitoring
• mA inputs: Available for analogue transmitter signals
• High-speed outputs: Available as an option
• Auxiliary supply: Wide-range AC/DC or low-range DC versions
• Configuration software: ABB PCM600
• Local interface: Graphical local display
• Web access: Web HMI
• Communication protocols: IEC 61850, Modbus, DNP3 and IEC 60870-5-103
• Process-bus support: IEC 61850-9-2 LE in supported configurations
• Time synchronisation: SNTP, IRIG-B and IEEE 1588, depending on the communication module
• Construction: Withdrawable plug-in relay unit
• Front protection: IP54 when flush mounted
• Operating temperature: Approximately –25°C to +55°C
• Installation altitude: Up to 2,000 metres

RET620 supports IEC 61850 Edition 2, IEC 61850-9-2 LE, IEC 60870-5-103, Modbus and DNP3 communication. ABB also identifies the 620 Series by its scalable functions and withdrawable-unit design.

The final specification must be checked from the complete ABB RET620 order code.

Features of ABB RET620

• Protection for two-winding power transformers
• Suitable for step-up transformers and generator-transformer blocks
• Stabilised transformer differential protection
• Fast differential protection for heavy internal faults
• Restricted earth-fault protection
• HV-side and LV-side REF protection
• Low-impedance and high-impedance REF arrangements
• Separate overcurrent protection for both transformer sides
• Earth-fault backup protection
• Negative-sequence overcurrent protection
• Transformer thermal overload protection
• Overexcitation protection
• Undervoltage and overvoltage protection
• Frequency protection
• Circuit-breaker failure protection
• Breaker opening and closing control
• Disconnector and earthing-switch control
• Synchronism and energising checks
• Optional automatic voltage regulation
• Optional OLTC control
• Optional transformer parallel-control functions
• Optional RTD and mA inputs
• Optional arc-flash protection
• Optional high-speed trip outputs
• Transformer current and voltage measurement
• Active and reactive power measurement
• Fault and disturbance recording
• Event recording
• Circuit-breaker condition monitoring
• Trip-circuit supervision
• IEC 61850 communication
• GOOSE messaging for protection and interlocking
• Local and remote relay operation
• Configuration through ABB PCM600

Transformer Differential Protection

RET620 compares the current measured on the HV and LV sides of the transformer. It operates when the difference indicates a fault inside the protected transformer zone.

This protection is used for faults such as:

• Internal transformer winding faults
• Phase-to-phase faults
• Transformer bushing faults
• Internal earth faults
• Faults within the CT protection zone

The relay compensates for the transformer ratio and vector group through its settings. This allows RET620 to be used with common transformer winding arrangements.

Restricted Earth-Fault Protection

Restricted earth-fault protection is used for sensitive detection of faults close to the transformer neutral.

RET620 supports:

• HV-side restricted earth-fault protection
• LV-side restricted earth-fault protection
• Low-impedance REF protection
• High-impedance REF protection

The correct arrangement depends on the transformer neutral earthing, phase CT ratios, neutral CT ratio and existing protection scheme.

Transformer Thermal and Overexcitation Protection

RET620 monitors transformer loading and provides thermal overload protection. RTD inputs can also be used for direct temperature signals such as:

• Transformer winding temperature
• Top-oil temperature
• Bottom-oil temperature
• Ambient temperature
• Dry-type transformer temperature
• Tap-changer temperature

Overexcitation protection monitors the voltage-to-frequency condition. It helps protect the transformer against excessive core flux caused by high voltage or low frequency.

Automatic Voltage Regulation

When ordered with the voltage regulator option, RET620 can control a transformer’s motor-operated on-load tap changer.

The relay monitors the regulated voltage and sends tap raise or lower commands when the voltage moves outside the set range.

For an ABB RET620 relay with automatic voltage regulation, buyers should share:

• Transformer rating
• Regulated-side voltage
• Number of tap positions
• Tap step percentage
• OLTC make and model
• Tap-position transmitter details
• Single or parallel transformer operation

Applications

ABB RET620 transformer protection relays are used for:

• Two-winding power transformers
• HV/MV transformers
• MV/MV transformers
• Step-up transformers
• Generator-transformer blocks
• Transformer differential protection
• Restricted earth-fault protection
• Transformer overcurrent backup protection
• Transformer thermal protection
• Transformer overexcitation protection
• Transformer incomer panels
• Automatic voltage regulation
• On-load tap-changer control
• Parallel transformer operation
• Utility substations
• Industrial substations
• Power plant auxiliary transformers
• Captive power plants
• Single-busbar substations
• Double-busbar substations
• New transformer protection panels
• Existing ABB RET620 replacement requirements

RET620 is commonly required by:

• Power utilities
• Power plants
• Transformer manufacturers
• Switchgear manufacturers
• EPC contractors
• Panel builders
• Steel plants
• Cement plants
• Mining companies
• Oil and gas facilities
• Refineries
• Petrochemical plants
• Renewable power projects
• Water-treatment plants
• Infrastructure projects
• Large manufacturing units

ABB RET620 Replacement

ABB RET620 is installed in many existing transformer protection panels. Buyers may require the same relay for maintenance, switchgear extensions, project standardisation or spare inventory.

ABB now positions REX615 as the next step for the earlier Relion 615 and 620 Series. REX615 supports transformer protection and automatic voltage regulation and is available in a wide version corresponding to the mechanical size of the 620 Series.

However, REX615 should not be selected as a RET620 replacement only by comparing the relay size. The existing protection functions, hardware modules, wiring and communication setup must be checked.

For an ABB RET620 replacement relay, please share:

• Complete RET620 order code
• Clear relay nameplate
• IEC or ANSI version
• Product and firmware version
• Transformer protection functions
• HV and LV CT ratios
• Neutral CT ratios
• VT ratio
• Auxiliary supply voltage
• Binary input voltage
• RTD and mA requirements
• Automatic voltage regulator option
• Arc-protection option
• Communication protocol
• Existing PCM600 configuration
• Panel cut-out and terminal arrangement

ABB supports retrofit and migration of Relion 620 Series relays to newer platforms such as REX615 and REX640. The replacement route should be selected according to the existing installation.

ARP IMPEX accepts enquiries against an ABB order code, relay nameplate, transformer datasheet, bill of quantities, single-line diagram or protection schedule.

Contact us for an ABB RET620 transformer protection relay price, matching replacement, configuration check or export quotation from India.