Basler Electric BE3‑32‑3AC Reverse Power Relay

The Basler Electric BE3‑32‑3AC (part number 9 1376 00 105) is a microprocessor‑based directional power relay that detects reverse power flow in three‑phase AC circuits. It is specifically designed to protect prime movers (steam turbines, gas turbines, diesel engines) from motoring, which occurs when the generator loses its prime mover power and draws energy from the grid. The relay trips when the reverse power exceeds a preset threshold for a selected time delay, preventing damage to the turbine or engine.

Measurement and Settings

The relay measures the real power (watts) using voltage and current inputs, and determines the direction of power flow. The pickup level is adjustable from 0.1 to 5% of rated power. The time delay is adjustable from 1 to 30 seconds. The relay includes a front‑panel LCD display for monitoring power values and settings. It also features a target indicator for trip identification.

Directional Sensing

The relay uses a phase‑angle comparison method to accurately determine power direction. It is insensitive to reactive power and harmonics, focusing solely on real power. A built‑in phase compensation adjusts for CT and PT phase errors. The relay includes a test mode for simulation of reverse power conditions.

Technical Specifications

Voltage input: 100‑480 VAC, 50/60 Hz. Current input: 1 A or 5 A secondary. Pickup accuracy: ±3% of setting. Time delay: 0.1‑30 seconds adjustable. 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. Complies with IEEE C37.90 and IEC 60255.

Applications

The BE3‑32‑3AC is used in utility generators, industrial co‑generation, and emergency standby systems. It provides primary protection against reverse power and can also be used for loss‑of‑excitation detection (in conjunction with other relays).

Installation and Commissioning

Mount the relay in a panel, connect voltage and current inputs with correct polarity, and connect control power. Commissioning involves setting pickup and time delay, and performing secondary injection tests. The relay includes a self‑diagnostic routine for health monitoring.

Reliability and Quality

Basler Electric’s BE3‑32‑3AC is built with high‑reliability components and is tested for surge, ESD, and temperature extremes. Its solid‑state design ensures long life and minimal maintenance.

Conclusion

The Basler Electric BE3‑32‑3AC reverse power relay (9 1376 00 105) is a precise, dependable, and user‑friendly solution for protecting generators from motoring damage. Its adjustable settings and rugged construction make it a trusted choice for power system protection.