TheABB RET521 (1MRK002239-BA)is a multifunctional protection, control, and measurement IED designed for medium-voltage networks. It is highly versatile, serving as primary protection for incoming/outgoing feeders and large three-phase AC motors. Additionally, it functions as reliable backup protection for power transformers and high-voltage line relays.
Technical Specifications
Model/Order Code:RET521 (1MRK002239-BA).
Series:REX 521.
Application:MV Feeders, Substation Protection, and Large AC Motors.
Inputs:Support for conventional CTs/VTs or Current/Voltage Sensors.
Control:Circuit breaker control and supervision.
Grounding Support:Isolated, resonant earthed, solidly earthed, and resistively earthed.
Functionality:Protection, Control, Measurement, and Supervision.
Configuration:Pre-made standard configurations for rapid deployment.
Key Features and Engineering Advantages
Dual-Input Flexibility:Available in hardware versions that support either traditional electromagnetic transformers (CT/VT) or modern, space-saving sensors.
Comprehensive Motor Protection:Specifically designed to manage the thermal and electrical stresses of large motor drives, preventing damage during start-up and operation.
Operational Efficiency:Standardized, pre-made configurations reduce the time required for engineering, parameterization, and commissioning.
Universal Feeder Application:Capable of managing both incoming and outgoing radial feeders, ensuring a consistent protection philosophy across the substation.
Advanced Connectivity:Enriched with extended measuring and supervision functions to provide deep insights into the health of the electrical network.
