ABB REX521 Feeder Protection Relay
Delivery time 3 days
Product origin New/used
Email plcru@foxmail.com
Mobile/wechat /WhatsApp +86 18185397189
ABB REX521 feeder protection relay is an excellent performance protection device
ABB REX521 feeder protection relay is an excellent performance protection device, widely used in power systems, providing comprehensive protection, measurement, recording, monitoring and control functions. The following is a detailed analysis of ABB REX521 feeder protection relay:
1. Product Overview
ABB REX521 feeder protection relay is an important member of ABB's power protection product line. It integrates protection, measurement and monitoring functions. It is suitable for medium-voltage feeders and large and medium-sized three-phase AC motors in neutral point ungrounded systems, neutral point direct grounding systems, low resistance grounding systems and resonant grounding systems. This relay not only has excellent performance, but also provides rich functional options to meet the needs of different users.
2. Protection function
ABB REX521 feeder protection relay provides a variety of protection functions to ensure the safe and stable operation of the power system. Specifically including:
Phase-to-phase overcurrent protection: monitor and protect the phase-to-phase overcurrent of the feeder or motor to prevent equipment damage caused by overcurrent.
Grounding protection: including zero-sequence overcurrent (grounding) protection, which is used to detect grounding faults, cut off the fault current in time, and prevent the fault from expanding.
Overvoltage and undervoltage protection: monitor and protect against voltage anomalies to prevent equipment from being damaged by over-high or under-low voltage.
Motor protection: such as thermal overload protection, inrush braking, reverse phase sequence protection, etc., to ensure that the motor can operate safely under various working conditions.
Frequency protection: monitor and protect against frequency anomalies to prevent equipment from being damaged by frequency fluctuations.
III. Measurement function
In addition to the protection function, ABB REX521 also has a wealth of measurement functions to enable users to monitor the operating status of the power system in real time. Specifically including:
Current and voltage measurement: can measure the current and voltage values of the feeder or motor, and provide real-time electrical parameters.
Power measurement: measures active power, reactive power and power factor to help users evaluate the operating efficiency of the equipment.
Power quality monitoring: measures the harmonic distortion rate (THD) of current and voltage to evaluate the power quality and ensure the stable operation of the power grid.
4. Monitoring and control functions
ABB REX521 feeder protection relay also provides comprehensive monitoring and control functions, including:
Circuit breaker status monitoring: real-time monitoring of the circuit breaker status to ensure its normal operation.
Tripping circuit monitoring: monitor the integrity of the tripping circuit to prevent false operation or refusal to operate.
Fault recording: a fault recording module is integrated internally, which can fully record the changes in electrical quantities before and after the fault occurs, providing an important basis for fault analysis.
Self-diagnosis function: It has self-diagnosis capabilities, can determine the integrity of the relay, and issue an alarm signal before the relay fails to work properly, while locking all protection functions and output contacts.
5. Communication function
ABB REX521 feeder protection relay has two independent communication ports, supports multiple communication protocols, and is convenient for users to quickly access the back-end systems of various manufacturers. Specific communication protocols include Modbus RTU/ASCII, DNP 3.0 and SPA protocols supported by the RS-485 interface, and IEC 60870-5-103, Modbus RTU/ASCII, DNP 3.0, LON and SPA protocols supported by the fiber optic interface.
VI. Human-machine interface
ABB REX521 feeder protection relay has a user-friendly human-machine interface, which is convenient for users to operate and monitor. Specifically include:
4×8 character LCD display: used to display current status, protection setting value and other information.
Directional navigation keyboard: convenient for users to set parameters and operate.
LED indicator: provides a variety of status indications, such as circuit breaker position, alarm, etc.
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