Basler BE1-51A Digital Overcurrent Relay
The Basler BE1-51A (model K2E-W6M-B1N0F, also referenced as BE151AK2EW6MB1N0F) is a high-performance digital overcurrent relay designed for generator, transformer, and feeder protection. This relay provides phase overcurrent (51) and ground overcurrent (51N) protection with programmable time-current curves, offering excellent coordination flexibility for demanding utility and industrial applications. The BE1-51A is built with advanced measurement and control capabilities, including event recording, comprehensive diagnostics, and programmable logic.
The relay features a user-friendly interface with a high-resolution display and keypad for local configuration and monitoring. It supports Modbus RTU or DNP3 communication for seamless integration with SCADA systems. The BE1-51A is housed in a rugged enclosure, suitable for panel mounting in substations and generator control rooms, and is designed for reliable operation in harsh environments.
Technical Specifications
Model: BE1-51A (K2E-W6M-B1N0F)
Protection functions: Phase overcurrent (51), ground overcurrent (51N)
Current sensing: 1/5 A CT inputs
Time-current curves: Definite time, IEC, IEEE, and user-definable
Pickup range: 0.05-20.00 A (adjustable)
Time dial: 0.05-15.00 (adjustable)
Accuracy: ±1% of pickup
Output contacts: 4 form C (trip, alarm, etc.)
Communication: Modbus RTU (RS-485) or DNP3
Power supply: 24-240 V AC/DC (universal)
Display: 4-line alphanumeric LCD with keypad
Event recording: 64 events, 20 fault records
Operating temperature: -40°C to +70°C
Certifications: CE, UL, RoHS
Functional Features
Overcurrent protection: Phase and ground fault protection with multiple curve options for precise coordination.
Programmable logic: Allows custom logic equations for advanced protection schemes.
High accuracy: ±1% ensures reliable protection and coordination.
Event recording: Stores fault data for post-fault analysis and system optimization.
Communication: Modbus or DNP3 enables remote monitoring and setting changes.
Typical Applications
Generator protection: Phase and ground fault backup protection.
Transformer protection: Overcurrent protection for power transformers.
Feeder protection: Protection of distribution feeders and cables.
Motor protection: Overcurrent and ground fault protection for large motors.
Installation and Configuration
Mount the BE1-51A on a panel. Connect the CT inputs, power supply, and output contacts. Configure the protection elements, time-current curves, and communication settings using the front-panel keypad or via communication. The relay includes comprehensive test and diagnostic tools for commissioning and maintenance.
Compliance
Complies with IEEE C37.90, IEC 60255, CE and UL approved, RoHS compliant.
Conclusion
The Basler BE1-51A provides advanced, flexible overcurrent protection for generators, transformers, and feeders, offering precision, reliability, and extensive communication capabilities for modern power systems.




