Basler BE1‑25/79TR Reclosing Relay

The Basler BE1‑25/79TR is a solid‑state reclosing relay designed for automatic reclosing of circuit breakers on distribution feeders and transmission lines. It combines synchronism check (25) and reclosing (79TR) functions to provide controlled re‑energization after a fault clearing. This relay is essential for improving system availability and reducing outage times.

Key Features

The relay features programmable reclosing sequences with adjustable dead times, reclaim times, and reset settings. It includes synchronism check to ensure voltage matching before closing. The relay provides multiple shots (typically up to 4) with independent timing. It includes LED status indication and a target indicator for operation logging.

Technical Specifications

Input voltage: 120 or 240 VAC, 50/60 Hz. Dead time range: 0.1‑60 seconds (adjustable). Reclaim time: 1‑120 seconds (adjustable). Reset time: 1‑120 seconds (adjustable). Synchronism check: adjustable voltage and phase angle. Output contacts: 2 form‑C rated at 5 A at 250 VAC. Operating temperature: -20°C to +55°C. Auxiliary supply: 120/240 VAC or 48/125 VDC.

Operating Principles

When a fault occurs and the breaker trips, the reclosing relay initiates a dead time delay. After the dead time, if the voltage conditions are within synchronism limits, the relay sends a close command to the breaker. If the fault is temporary, the breaker stays closed and the reclaim timer starts. If a permanent fault persists, the breaker trips again and the next shot in the sequence is initiated. After a preset number of unsuccessful reclosures, the relay locks out.

Applications

This relay is used on distribution feeders, transmission lines, and industrial power systems. It is essential for overhead line applications where temporary faults are common, improving system reliability.

Installation and Configuration

Mount the relay in a standard panel cutout. Connect voltage inputs, auxiliary power, and trip/close circuits. Adjust dead times, reclaim time, and synchronism settings using front‑panel controls. A functional test is recommended to verify the reclosing sequence.

Maintenance and Reliability

Solid‑state construction ensures high reliability. Periodic testing of the reclosing sequence is recommended. Routine inspection of connections is sufficient.

Conclusion

The Basler BE1‑25/79TR reclosing relay provides reliable and adjustable auto‑reclosing with synchronism check, enhancing power system availability and reducing outage durations.