Basler Electric BE1‑59 Over Voltage Relay

The Basler Electric BE1‑59 is a solid‑state overvoltage relay that monitors single‑phase or three‑phase AC voltages and operates when the voltage exceeds a preset threshold. It is widely used to protect generators, transformers, and distribution feeders from sustained overvoltage conditions that can cause insulation failure, equipment overheating, and system instability. The relay offers adjustable pickup settings, time delays, and a rugged design for reliable protection.

Operating Principle

The relay continuously measures the RMS voltage of the monitored circuit. When the voltage exceeds the pickup setting for a selected time delay, the relay trips. The pickup is adjustable from 1 to 300 VAC (depending on model), and the time delay can be set from 0.1 to 10 seconds. A built‑in filter reduces harmonics and transient noise to prevent nuisance tripping. The relay includes a target indicator for trip identification.

Key Features

Front‑panel potentiometers for pickup and time delay adjustment. LED indicators for voltage presence and trip status. A test pushbutton for functional verification. Output contacts: 1 Form C (SPDT) rated 5 A at 250 VAC. The relay is housed in a metal enclosure suitable for panel mounting. It operates from a wide range of DC or AC control voltages.

Technical Specifications

Input voltage: 1‑300 VAC, 50/60 Hz. Pickup accuracy: ±2% of setting. Time delay accuracy: ±3% or 50 ms. Output contacts: 1 SPDT, 5 A at 250 VAC. Power supply: 24‑250 VDC or 120‑240 VAC. Burden:<5 VA. Operating temperature: –20°C to +65°C. Meets ANSI/IEEE C37.90 surge withstand.

Applications

The BE1‑59 is used on generator voltage regulators, transformer tap changers, and distribution feeders. It provides protection against over‑excitation, load rejection, and voltage regulator failures. It can be coordinated with other relays for selective tripping.

Installation and Commissioning

Mount the relay in a standard panel cutout. Connect voltage sensing leads and control power. Commissioning involves setting the pickup and time delay values, then testing with a variable AC source to verify trip accuracy. The relay includes a built‑in test jack for signal injection.

Reliability and Quality

Basler Electric’s BE1‑59 is built with solid‑state technology and conformal coating for environmental resilience. It is factory calibrated and requires minimal maintenance. The relay has a long service life and proven performance in critical applications.

Conclusion

The Basler Electric BE1‑59 overvoltage relay is a precise, reliable, and easy‑to‑use protection device for overvoltage conditions. Its adjustable settings and robust construction make it an essential component in any power system protection scheme.