Basler SSR 125‑9 Static Voltage Regulator

The Basler SSR 125‑9 is a static voltage regulator designed for medium to large synchronous generators. Identified by part number 1256 00 102, this regulator provides reliable excitation control with an output rating of up to 125 V DC at 9 A continuous. It is part of the SSR series, known for robust construction and simple adjustment, making it suitable for demanding industrial, utility, and marine applications.

Key Features

The regulator features adjustable voltage setpoint, stability control, and reactive droop compensation. It includes over‑excitation and under‑excitation protection, as well as a soft‑start function to reduce voltage overshoot. Status LEDs indicate power, regulation, and fault conditions. The unit is built with a robust heatsink for efficient thermal management and is housed in a rugged enclosure for panel mounting.

Technical Specifications

Sensing input: 110‑480 VAC, 50/60 Hz. Auxiliary power: 120‑240 VAC. Output voltage: adjustable up to 125 VDC. Continuous current: 9 A, peak 14 A. Regulation accuracy: ±0.5%. Response time: less than 30 milliseconds. Operating temperature: -20°C to +65°C. Enclosure: panel mount with IP20 protection. Connections are via screw terminals for secure wiring.

Operating Principles

The SSR 125‑9 compares the sensed generator voltage with a reference and generates an error signal that controls the firing angle of the SCR power bridge, modulating the exciter field current. The PID loop ensures stable voltage under steady‑state and transient conditions. Droop adjustment allows proper reactive power sharing when multiple generators are paralleled. The soft‑start function gradually applies excitation during startup to minimize mechanical and electrical stress.

Applications

This regulator is used in standby and prime power generators, marine propulsion systems, and co‑generation plants. It is suitable for generators with brushless exciters requiring moderate to high excitation power. Typical installations include industrial facilities, data centers, hospitals, and offshore platforms.

Installation and Configuration

Mount the regulator on a panel with adequate ventilation. Connect the sensing, power, and field leads per the wiring diagram. Adjust the voltage setpoint, stability, and droop using the front‑panel potentiometers. A load bank test is recommended to verify regulation performance and fine‑tune the settings for the specific generator.

Maintenance and Reliability

The solid‑state design minimizes maintenance. Periodically check connections and clean the unit to ensure proper cooling. The regulator is protected against short circuits and overvoltage, ensuring long‑term reliability in continuous duty applications.

Conclusion

The Basler SSR 125‑9 static voltage regulator provides precise and dependable excitation control, making it a valuable component for medium to large generator applications.