Basler PRP320 Motor Pull‑out Relay

The Basler PRP320 is a solid‑state relay designed to protect large synchronous motors from pull‑out (loss of synchronism) conditions. It continuously monitors the motor's terminal voltage and current to detect when the motor is operating at its stability limit. If a pull‑out condition is detected, the relay initiates a trip to prevent damage to the motor and driven equipment. This relay is essential for ensuring the reliability of critical motor applications.

Key Features

The relay features adjustable pull‑out detection setpoints and time delays. It includes high‑accuracy sensing with minimal drift. The unit provides a target indicator for fault identification and test points for calibration. Front‑panel LEDs indicate power, status, and trip conditions. The relay is housed in a rugged draw‑out case for easy maintenance.

Technical Specifications

Input voltage: 120 or 240 VAC, 50/60 Hz. CT secondary: 5 A or 1 A. Pull‑out pickup: adjustable based on power angle or current. Time delay: 0.1‑10 seconds (adjustable). Output contact rating: 5 A at 250 VAC resistive. Operating temperature: -20°C to +55°C. Auxiliary supply: 120/240 VAC or 48/125 VDC.

Operating Principles

The relay monitors the motor's voltage and current to calculate the power angle or slip. When the motor approaches pull‑out, the power angle increases beyond a safe limit. The relay compares the measured value against the setpoint and initiates timing if the pull‑out condition persists, tripping the motor before damage occurs.

Applications

This relay is used in large synchronous motors driving compressors, pumps, and mills in industrial plants, utilities, and mining operations.

Installation and Configuration

Mount the relay in a standard panel cutout. Connect voltage and current inputs, auxiliary power, and trip circuits. Adjust the pickup setpoint and time delay using front‑panel controls. A secondary injection test is recommended.

Maintenance and Reliability

Solid‑state design ensures high reliability. Periodic testing and calibration are recommended. Routine visual inspection of connections is sufficient.

Conclusion

The Basler PRP320 motor pull‑out relay provides dependable protection against loss of synchronism, ensuring safe and reliable operation of large synchronous motors.