Basler BE1-47N Voltage Phase Sequence Relay

The Basler BE1-47N is a digital voltage phase sequence relay designed to protect generators, motors, and other three‑phase equipment from phase reversal, phase loss, and undervoltage conditions. This relay continuously monitors the three‑phase voltage inputs and trips the circuit breaker when an abnormal phase sequence, missing phase, or voltage imbalance is detected, preventing equipment damage and ensuring safe operation.

The BE1-47N features a microprocessor‑based design with high accuracy and programmable settings. It includes a front‑panel display and keypad for local configuration and monitoring, and supports Modbus communication for remote supervision. The relay is housed in a rugged enclosure suitable for panel mounting in generator control rooms, motor control centers, and substations, and is designed for reliable operation in harsh industrial environments.

Technical Specifications

• Model: BE1-47N

• Protection functions: Phase sequence (reverse phase), phase loss, undervoltage (27), voltage unbalance (47)

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

• Phase sequence detection: Positive or negative (adjustable)

• Undervoltage pickup: 0‑120 V (adjustable)

• Voltage unbalance pickup: 2‑20% (adjustable)

• Time delay: 0.1‑30 seconds (adjustable)

• Accuracy: ±1% of setting (voltage), ±0.5% (phase angle)

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

• Communication: Modbus RTU (RS‑485) optional

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

• Display: 2‑line LCD with keypad

• Event recording: 64 events, 20 fault records

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

• Certifications: CE, UL, RoHS

Functional Capabilities

• Phase sequence protection: Detects reversed phase rotation and trips to prevent motor reversal or generator instability.

• Phase loss detection: Identifies missing phases, ensuring the equipment is not operated with single‑phase conditions.

• Undervoltage protection: Provides independent undervoltage elements with adjustable pickup and time delay.

• Voltage unbalance protection: Monitors phase‑to‑phase voltage asymmetry to prevent motor overheating and generator negative‑sequence heating.

• Programmable logic: Allows custom logic equations for advanced protection schemes using the relay's inputs and outputs.

• Diagnostic self‑test: Continuous monitoring of internal circuits and power supply for enhanced reliability.

Typical Applications

• Generator protection: Prevents operation with incorrect phase rotation and protects against voltage unbalance.

• Motor protection: Safeguards large motors from reverse rotation, single‑phasing, and undervoltage.

• Feeder protection: Ensures correct phase sequence and voltage quality for distribution feeders.

• Transformer protection: Monitors primary voltage for phase anomalies.

• Uninterruptible power supplies (UPS): Protects bypass and inverter inputs from phase faults.

Installation and Commissioning

Mount the BE1-47N on a panel using the provided brackets. Connect the three‑phase voltage inputs from the potential transformers or directly from the bus, the power supply, and the output relay contacts to the circuit breaker trip coil and alarm circuits. Configuration is performed using the front‑panel keypad: set the nominal voltage, phase sequence (positive or negative), undervoltage pickup and time delay, and voltage unbalance threshold. The relay includes a built‑in test mode that allows verification of wiring and settings without tripping the breaker. The event recorder can be accessed for post‑fault analysis. The relay also supports remote configuration and monitoring via Modbus RTU, enabling integration with SCADA systems.

Compliance and Environmental

The BE1-47N complies with IEEE C37.90 and IEC 60255 standards for protective relays. It carries CE and UL marks and is RoHS compliant. The relay is rated for operation in pollution degree 2 environments, with a wide temperature range that permits installation in unconditioned areas. It is designed for long‑term reliability with an MTBF exceeding 100,000 hours.

Conclusion

The Basler BE1-47N voltage phase sequence relay offers comprehensive protection against phase reversal, phase loss, undervoltage, and voltage unbalance in a single, compact package. Its versatile settings, diagnostic capabilities, and communication options make it an ideal choice for safeguarding critical motors, generators, and feeders in industrial and utility power systems.