Basler BE1‑50G Ground Overcurrent Relay

The Basler BE1‑50G is a solid‑state instantaneous ground overcurrent relay designed for fast detection and tripping of ground faults in distribution feeders, transformers, and motor circuits. This model, with configuration BE1‑50G2FA1PH0N0F, operates without intentional time delay, providing high‑speed protection for single‑line‑to‑ground faults. It is essential for minimizing equipment damage and maintaining system safety.

Key Features

The relay features an adjustable pickup current setting with high accuracy. It provides a high‑speed output contact for immediate tripping. The unit includes a target indicator for fault identification and test points for calibration. Its solid‑state design ensures long‑term stability and immunity to vibration.

Technical Specifications

CT secondary rating: 5 A or 1 A. Pickup range: 0.5‑20 A (adjustable). Operating time: less than 25 milliseconds. Output contact rating: 5 A at 250 VAC. Operating temperature: -20°C to +55°C. Auxiliary supply: 120/240 VAC or 48/125 VDC.

Operating Principles

The relay continuously monitors the ground current from a CT (typically a zero‑sequence CT or residual connection). When the current exceeds the pickup setting, the output relay trips the breaker without intentional delay. The instantaneous action provides fast protection for ground faults, reducing thermal and mechanical stress on equipment.

Applications

This relay is used for instantaneous ground fault protection of feeders, transformers, and motors. It is often used in combination with time‑overcurrent relays for coordinated protection schemes.

Installation and Configuration

Mount the relay in a standard panel cutout. Connect the CT leads, auxiliary power, and trip circuits. Set the pickup using the front‑panel knob. A secondary injection test is recommended to verify the pickup setting.

Maintenance and Reliability

Routine maintenance includes visual inspection and periodic calibration checks. The solid‑state design provides high reliability with no moving parts.

Conclusion

The Basler BE1‑50G ground overcurrent relay provides fast and reliable protection for ground faults, ensuring minimal damage and enhanced system safety.