Basler BE1-27 Under-Voltage Relay

The Basler BE1-27 (cat. A3EA1JN1N4F, UI‑211) is a digital under-voltage relay designed to protect generators, motors, and other electrical equipment from undervoltage conditions. This relay monitors the system voltage and trips the circuit breaker when voltage falls below a preset threshold, preventing equipment damage, stalling, and instability. The BE1-27 is widely used in industrial and utility power systems.

The relay features microprocessor-based measurement with high accuracy and adjustable pickup and time delay settings. It includes a front-panel display and keypad for local configuration and monitoring. The BE1-27 supports Modbus communication for remote supervision. Its rugged construction and wide temperature range make it suitable for demanding applications.

Technical Specifications

• Model: BE1-27 (A3EA1JN1N4F)

• Protection type: Under-voltage (27)

• Voltage sensing: 3-phase, 0-600 V AC (PT or direct)

• Pickup range: 0-120 V (adjustable)

• Time delay: 0.1-30 seconds (adjustable)

• Accuracy: ±1% of setting

• Output contacts: 2 form C (trip and alarm)

• Communication: Modbus RTU (optional)

• Power supply: 24-240 V AC/DC (universal)

• Display: 2-line LCD with keypad

• Operating temperature: -40°C to +70°C

• Certifications: CE, UL, RoHS

Functional Features

• Under-voltage protection: Trips when voltage falls below pickup setting.

• Adjustable settings: Pickup and time delay can be field-adjusted.

• Voltage unbalance detection: Optional element to detect asymmetry.

• Event recording: Stores undervoltage events for analysis.

• Communication: Modbus enables remote monitoring.

Typical Applications

• Generator protection: Tripping on undervoltage to prevent motor stalling.

• Motor protection: Preventing low-voltage operation that can cause overheating.

• Feeder protection: Undervoltage tripping of distribution feeders.

• Load shedding: Initiating load shedding during severe voltage dips.

Installation and Configuration

Mount the BE1-27 on a panel. Connect the PT inputs, power supply, and output contacts. Configure the pickup level and time delay using the front-panel keypad. The relay includes a test mode for commissioning.

Compliance

Complies with IEEE C37.90, IEC 60255, CE and UL approved, RoHS compliant.

Conclusion

The Basler BE1-27 provides reliable under-voltage protection for critical power system equipment, ensuring safe operation and preventing damage from low-voltage conditions.