Basler Electric SSR 125-12NF – High‑Current Static Voltage Regulator

The Basler Electric SSR 125-12NF (part number 9 1859 00 106) is a high‑capacity static voltage regulator engineered for large synchronous generators that demand substantial field current. With a continuous output rating of 125 A, this regulator is capable of driving the most demanding excitation systems, making it a preferred choice for utility‑scale and heavy‑industrial power generation.

Design and Performance

The SSR 125-12NF features a robust thyristor bridge with advanced gate control, providing smooth and precise regulation of field current. Its digital control core offers fast transient response and exceptional stability. The regulator includes comprehensive protection: over‑excitation limiting, under‑frequency roll‑off, loss‑of‑sensing detection, and SCR overtemperature monitoring. Communication interfaces enable integration with plant SCADA and DCS systems.

• Input sensing: 120/240/480 V AC, 50/60 Hz

• Output current: 125 A continuous (150 A for 30 seconds)

• Output voltage: up to 300 V DC

• Regulation accuracy: ±0.25% of setpoint

• Response time: < 30 ms for 10% step change

• Protections: over/under voltage, over/under frequency, field overcurrent, SCR misfire

• Communication: RS‑485 Modbus and optional Ethernet

• User interface: LCD display with keypad

• Cooling: forced air with temperature‑controlled fans

• Operating temperature: –20 °C to +60 °C

Typical Applications

This regulator is suitable for generators up to 10 MVA in utility power plants, large industrial co‑generation, and marine propulsion systems. Its high output capacity and robust construction ensure reliable operation in the most demanding environments.

Installation and Configuration

Mounting requires a dedicated cabinet with adequate ventilation. Power connections are via bus bars, and control wiring uses pluggable terminals. Configuration is performed through the front‑panel interface or via Basler software, allowing for comprehensive parameter customisation.

Reliability and Testing

Each SSR 125-12NF undergoes full‑load testing, dielectric withstand, and thermal cycling before delivery. It complies with IEEE C37.90 and IEC 60255 standards, ensuring long‑term dependability.

In summary, the Basler Electric SSR 125‑12NF static voltage regulator delivers uncompromising excitation control for large generators, backed by robust design and advanced protection features.