Product Description
I. Overview
ABB REF620E_F is an intelligent relay protection device integrating protection, control, measurement, and monitoring functions. It is specially designed for medium and high voltage power systems and is widely used in public utility and industrial power distribution systems, covering radial, ring, and mesh networks. It can be perfectly adapted to both traditional power grids and new power systems integrated with distributed generation.
REF620E_F can collect various electrical parameters in real-time, quickly respond to abnormal situations such as overcurrent, short circuit, and ground fault in the line, cut off the faulty line in time, ensure the safe operation of production equipment, and avoid production stagnation and economic losses caused by power failures. In terms of public utilities, urban distribution networks require precise control and protection. REF620E_F can finely manage each feeder to ensure stable power supply to thousands of households and improve power supply reliability. Its excellent compatibility and scalability allow it to be easily integrated into existing power systems, work in coordination with other equipment, and provide solid support for building an intelligent and efficient power network.

II. Technical Parameters
(I) Electrical Parameters
Rated Voltage: It has a wide voltage adaptation capability and can support an input voltage range of 100-250V AC/125-250V DC. This wide voltage range design enables it to easily cope with the voltage standards of different power systems. Whether it is the common industrial power voltage or the power supply voltage in some special occasions, it can work stably, greatly improving the versatility and applicability of the equipment.
Rated Current: It can withstand a maximum rated current of 4000A, which can meet the protection and control needs of large-capacity circuits in medium and high voltage power systems. In the incoming and outgoing circuits of large substations and the power supply lines of high-power equipment in industrial plants, such a high rated current carrying capacity ensures that the device can still operate reliably under high current conditions, accurately collect current signals and take corresponding protection actions.
Frequency Range: The operating frequency range is 45-65Hz, covering the power system frequency standards of most regions in the world. Whether it is a 50Hz standard power frequency grid or a 60Hz special grid, REF620E_F can be stably adapted to ensure consistent performance in different frequency environments.
(II) Protection Function Parameters
Overcurrent Protection: It is equipped with a multi-stage overcurrent protection function, and the protection threshold and action time can be flexibly adjusted according to the actual application scenario. The fast overcurrent protection section can quickly cut off the circuit when the short-circuit current increases instantaneously to avoid serious damage to the equipment; while the delayed overcurrent protection section is used to deal with continuous overload current, and timely protect the equipment from overload hazards on the premise of not affecting normal production operations. The action accuracy of overcurrent protection can reach ±5%, ensuring accurate judgment of current abnormalities.
Ground Fault Protection: It is equipped with unique multi-frequency admittance ground protection technology, which has higher sensitivity and selectivity compared with traditional ground protection methods. It can accurately detect ground faults in the system, quickly locate the fault point, and the action time is less than 20ms, which greatly improves the handling efficiency of ground faults and effectively reduces the safety risks caused by ground faults.
Other Protection Functions: It also has various protection functions such as phase imbalance protection, undervoltage protection, overvoltage protection, and zero-sequence current protection. Phase imbalance protection can monitor the balance of three-phase currents, and when the current imbalance exceeds the set threshold, it will promptly issue an alarm and take protection measures; undervoltage protection and overvoltage protection respectively target the situations of too low or too high voltage to protect the equipment from the impact of abnormal voltage; zero-sequence current protection is specially used to detect zero-sequence current in the system, providing additional protection for ground faults in neutral grounded systems.

(III) Communication Parameters
Support for Communication Protocols: It fully supports a variety of mainstream communication protocols, including IEC 61850 Editions 1 and 2, Modbus, DNP3, and IEC 60870-5-103. Among them, as an international standard communication protocol in the field of power system automation, the support of REF620E_F for IEC 61850 realizes seamless communication and interoperability with other intelligent devices complying with this standard, facilitating the construction of digital substations and smart grids; Modbus protocol, with its characteristics of simplicity, ease of use, and strong compatibility, facilitates communication connection with some traditional industrial equipment; DNP3 protocol is often used for remote monitoring and data acquisition of power systems to ensure reliable data transmission between remote terminals and master stations; IEC 60870-5-103 protocol focuses on communication between relay protection devices and automation systems to ensure accurate interaction of protection information.
Time Synchronization: It supports multiple time synchronization methods, including high-precision IEEE 1588 V2 Precision Time Protocol. Through accurate time synchronization, REF620E_F can ensure that the event records and protection action times of various devices in the entire power system are highly consistent, providing an accurate time basis for accident analysis and fault troubleshooting, and improving the efficiency and accuracy of power system operation management.
(IV) Physical Parameters
Dimensions: Adopting a compact design concept, the dimensions are 200mm × 100mm × 75mm (length × height × width). The small size allows it to be easily installed in equipment with limited space such as control cabinets and switch cabinets, saving valuable installation space and facilitating the integration and layout of equipment.
Weight: The weight is about 1.5kg. The lightweight design not only facilitates on-site installers to carry and install, reducing physical consumption, but also reduces the difficulty of operation during equipment maintenance and replacement, improving work efficiency.
Protection Level: The protection level reaches IP20, which can effectively prevent solid foreign objects larger than 12mm from entering the equipment, protect the internal circuit from interference and damage from dust, small tools, and other objects, and ensure the stable operation of the equipment in conventional indoor environments.

III. Functional Characteristics
(I) Powerful Protection Function System
Comprehensive Fault Detection: REF620E_F has a built-in advanced fault detection algorithm, which can monitor multiple electrical parameters such as current, voltage, and power in the power system in real-time. Through comprehensive analysis of these parameters, it can accurately identify various fault types, such as phase-to-phase short circuit, ground short circuit, overload, undervoltage, overvoltage, etc. In the complex operating environment of the power system, even if there are multiple interference factors, it can accurately capture fault signals, providing a reliable basis for subsequent protection actions.
Flexible Protection Configuration: It supports users to flexibly configure protection parameters and functions according to different application scenarios and needs of power systems. Users can personalize settings such as the action current and action time of overcurrent protection, the sensitivity of ground fault protection, and the activation/deactivation of various protection functions through professional configuration software. This flexible configuration method enables REF620E_F to adapt to diverse operating requirements of power systems, providing the most appropriate protection scheme whether it is a simple radial distribution line or a complex mesh grid structure.
(II) Efficient Control and Monitoring Functions
Real-time Control Operations: It has powerful control functions and can perform remote or local control operations on circuit breakers, disconnectors, and other equipment in the power system. By receiving control commands from the upper computer system through the communication interface, it can quickly and accurately execute the opening and closing operations of the equipment, realizing flexible adjustment of the operation mode of the power system. When a fault occurs in the power system, it can automatically control the action of related equipment according to preset logic, quickly isolate the fault area, and restore the normal operation of the system.
Accurate Monitoring and Data Acquisition: It performs high-precision real-time monitoring and data acquisition of the operating parameters of the power system, including three-phase voltage, current, active power, reactive power, power factor, frequency, etc. The collected data is not only used for the judgment of protection functions but also can be uploaded to the upper computer system in real-time through the communication interface, providing rich and accurate data support for the operation management, fault analysis, load forecasting, etc., of the power system. The data acquisition accuracy can reach 0.2 level, ensuring the reliability and availability of monitoring data.
(III) Convenient Communication and Interaction Functions
Integration of Multiple Communication Interfaces: It integrates rich communication interfaces. In addition to supporting multiple communication protocols, it also has common physical interfaces such as Ethernet interface and RS-485 interface. Through the Ethernet interface, high-speed and stable data transmission can be realized, facilitating data interaction and collaborative work with other intelligent devices in the smart grid; the RS-485 interface can be used to connect devices that do not require high communication rates but need long-distance transmission, such as some sensors and smart meters, expanding the communication connection capability of the device.
Friendly Human-machine Interface: It is equipped with a large LCD display and simple and intuitive operation buttons, providing users with a convenient human-machine interaction experience. The LCD display can display the operating parameters, equipment status, fault alarm information, etc., of the power system in real-time, with rich and easy-to-read display content. The operation buttons are reasonably arranged, and users can easily perform parameter settings, function switching, event query, and other operations through the buttons, even non-professionals can quickly get started. At the same time, it also supports remote access and operation through a web browser. Users only need to enter the IP address of the device on a terminal device with a network connection to realize remote monitoring and management of REF620E_F through the browser interface, which greatly improves the flexibility and convenience of device operation.

IV. Application Scenarios
(I) Power Industry
Substation Protection and Control: In substations, REF620E_F undertakes key protection and control tasks. It is used to monitor the electrical parameters of substation incoming and outgoing lines and provide rapid protection against overcurrent, short circuit, ground fault, etc. When a short-circuit fault occurs in the incoming line, REF620E_F can detect the fault current in milliseconds, quickly issue a trip command, cut off the faulty line, and protect the equipment in the substation from damage. At the same time, through real-time monitoring of bus voltage and current, it can automatically adjust the tap of the transformer according to changes in system load to realize stable voltage regulation and ensure the reliability and stability of substation power supply.
Distribution Network Automation: In the distribution network automation system, REF620E_F plays an important role as an intelligent terminal device. It performs real-time monitoring and protection of feeders in the distribution network, and uploads the collected electrical parameters and equipment status information to the distribution automation master station through the communication network. When a feeder fault occurs, it can realize rapid fault location and isolation, restore power supply to non-faulty areas by automatically controlling switchgear, shorten power outage time, and improve power supply quality. In the case of a single-phase ground fault, REF620E_F uses its advanced ground fault protection function to accurately determine the faulty line, and remotely control related switches through the automation system to isolate the fault section and quickly restore normal power supply in other areas.
(II) Industrial Field
Industrial Enterprise Power Supply System: The internal power supply systems of various industrial enterprises have high requirements for power stability and reliability. REF620E_F can be used to protect the incoming and outgoing lines of high-voltage switchgear in industrial enterprises and the power supply lines of important production equipment. In iron and steel plants, it protects the power supply lines of large equipment such as blast furnaces and converters, monitors current and voltage in real-time, prevents damage to equipment caused by faults such as overcurrent and undervoltage, and ensures the continuity of the production process. In chemical enterprises, due to the complex production environment, the safety requirements for the power system are more stringent. The multiple protection functions of REF620E_F can effectively deal with the electrical fault risks in chemical production and ensure production safety.
Automated Production Line Control: In industrial automated production lines, REF620E_F can be used as the core equipment for power control and protection. It monitors and protects the power supply of motors, frequency converters, and other equipment on the production line to ensure the normal operation of the equipment. When the motor has faults such as overload and short circuit, REF620E_F cuts off the power supply in time to protect the motor from damage, and feeds back the fault information to the production line control system through the communication interface, facilitating staff to carry out fault troubleshooting and repair in a timely manner, avoiding production line shutdown caused by equipment faults, and improving production efficiency.
(III) Renewable Energy Field
Wind Farms and Photovoltaic Power Plants: With the rapid development of renewable energy, the scale of wind farms and photovoltaic power plants is constantly expanding. REF620E_F is used in wind farms and photovoltaic power plants to protect and control the connection lines between power generation equipment and the power grid. In wind farms, it protects the outgoing lines of box-type transformers of wind turbines and collector lines, monitors parameters such as current and voltage, and prevents line faults from affecting the normal power generation of wind turbines. In photovoltaic power plants, it is used to protect the outgoing lines of combiner boxes of photovoltaic arrays and the input and output lines of inverters, ensuring safe and stable power transmission between the photovoltaic power generation system and the power grid. When a DC side ground fault occurs in a photovoltaic power plant, REF620E_F can quickly detect and locate the fault point, take corresponding protection measures, and ensure the reliable operation of the photovoltaic power plant.
Distributed Energy Access: In the scenario of distributed energy access to the power grid, REF620E_F plays an important role in coordination and protection. When distributed energy such as small wind turbines, photovoltaic power generation devices, and energy storage equipment is connected to the power grid, it may affect the stability of the power grid. REF620E_F can monitor the electrical parameters of the distributed energy access point in real-time, protect against abnormal situations such as overcurrent, overvoltage, and undervoltage, and realize coordinated operation between distributed energy and the power grid through communication with the grid automation system, ensuring the safe and stable access of distributed energy to the power grid and improving energy utilization efficiency.