Basler Electric BE1A-25-M1G-A6T-N4V1F Sync-Check Relay

The Basler Electric BE1A‑25 is a microprocessor‑based synchronism‑check relay that ensures safe closure of circuit breakers when connecting two independent AC sources. It verifies that the voltage magnitude, phase angle, and frequency difference are within acceptable limits before issuing a permissive signal. This relay is essential for generator paralleling, bus tie automatic transfer, and network interconnection applications.

Measurement and Settings

The BE1A‑25 measures both three‑phase voltages and compares them. It offers independently adjustable settings for voltage match (1‑20% of nominal), phase angle (1‑30 degrees), and slip frequency (0.05‑1.0 Hz). A dwell timer (0.1‑10 seconds) ensures that the conditions are stable before allowing closure. The relay also supports a live‑line / dead‑line logic for automatic transfer schemes, permitting closure when one side is de‑energized.

User Interface

A front‑panel LCD display shows measured values and settings. Four pushbuttons allow navigation and adjustment of parameters. The relay includes LED indicators for source presence, synchronism status, and relay health. An RS‑232 port enables communication with a PC for configuration and monitoring.

Technical Specifications

Voltage input: 100‑480 VAC, 50/60 Hz. Accuracy: ±1% for voltage, ±0.5 degree for phase. Output contacts: 2 Form C, rated 5 A at 250 VAC. Power supply: 24‑250 VDC or 120‑240 VAC. Operating temperature: –30°C to +70°C. The relay is housed in a rugged enclosure with IP30 protection.

Applications

Used in utility substations, industrial cogeneration plants, and marine power systems, the BE1A‑25 ensures safe paralleling of generators with the grid or with each other. It is also employed in automatic bus transfer schemes to maintain supply continuity for critical loads.

Installation and Commissioning

Mount the relay in a standard panel cutout. Connect voltage inputs from both sources. Set the parameters via the front panel or software. Commissioning involves verifying the accuracy of measurements against a reference and testing the permissive output under various conditions.

Reliability and Quality

The BE1A‑25 is built to Basler Electric’s high standards, compliant with IEEE C37.90 and IEC 60255. It features self‑diagnostics and watchdog timers to ensure reliable operation. The relay’s solid‑state design and non‑volatile memory guarantee long‑term performance.

Conclusion

The Basler Electric BE1A‑25‑M1G‑A6T‑N4V1F sync‑check relay offers advanced, flexible, and reliable synchronism checking for modern power systems. Its precise control and robust construction make it an indispensable tool for safe and efficient source paralleling.