Basler 9507900107 SR8A Retrofit Static Voltage Regulator

The Basler 9507900107 is a retrofit static voltage regulator designed to replace older SR8A series regulators in synchronous generator applications. This unit operates on 50/60 Hz systems with a nominal input of 240 VAC, providing reliable excitation control to maintain stable generator terminal voltage. It is engineered for easy installation in existing panels, offering upgraded performance and reliability for aging generator control systems.

Key Features

The regulator features adjustable voltage setpoint, stability compensation, and reactive droop control for parallel operation. It includes over‑excitation and under‑excitation protection, as well as a soft‑start function to minimize voltage overshoot during startup. Status LEDs provide clear indication of power, regulation, and fault conditions. The retrofit design ensures compatibility with existing mounting and wiring configurations.

Technical Specifications

Input voltage: 240 VAC, 50/60 Hz. Sensing input: 110‑480 VAC. Output voltage: adjustable up to 150 VDC for the exciter field. Continuous current rating: 5 A, peak 10 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 SR8A retrofit regulator compares the sensed generator voltage with an internal reference. Any deviation generates an error signal that adjusts the firing angle of the SCR power bridge, modulating the exciter field current. The control loop uses a PID algorithm for stable performance. Droop compensation adjusts the voltage setpoint proportionally to reactive current, enabling stable reactive power sharing when multiple generators are paralleled.

Applications

This regulator is used in standby and prime power generators, marine vessels, and industrial co‑generation plants. It is ideal for retrofitting older SR8A regulators in existing generator control panels, providing modern performance with minimal downtime.

Installation and Configuration

Mount the regulator in the existing panel using the provided brackets. Connect the sensing voltage leads, auxiliary power, and exciter field wiring per the interconnection 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.

Maintenance and Reliability

Solid‑state design ensures high reliability with minimal maintenance. Routine inspection of connections and cleaning of the unit is sufficient. The regulator includes protection against short circuits and overvoltage, ensuring long service life.

Conclusion

The Basler 9507900107 SR8A retrofit static voltage regulator delivers dependable excitation control with modern features, making it a trusted solution for upgrading generator voltage regulation systems.