Basler Electric SR4A‑2B15B3A Static Voltage Regulator

The Basler Electric SR4A‑2B15B3A is a high‑performance static voltage regulator designed for synchronous generators with a 120 VAC sensing input at 50/60 Hz. It provides automatic voltage regulation with an accuracy of ±0.5% and a fast transient response of less than 40 ms. The regulator delivers a high excitation output current of up to 15 A, making it suitable for medium to large generators in industrial, marine, and utility applications. Its robust design ensures reliable operation in demanding environments.

Control and Adjustment

The regulator features a proportional‑integral (PI) control loop with adjustable gain and stability to match generator and exciter dynamics. Voltage setpoint is adjustable from 90% to 110% of nominal via a front‑panel potentiometer. Droop control (0‑5%) enables reactive load sharing in parallel operation. An under‑frequency roll‑off reduces excitation when the frequency drops below a preset threshold, preventing over‑excitation. A remote voltage trim input allows external control for system integration.

Excitation Output

Output voltage: 0‑150 VDC, continuous current up to 15 A (peak 25 A). The output is short‑circuit protected and current‑limited. The regulator includes over‑excitation protection and a soft‑start function to prevent voltage overshoot during build‑up. A field current monitor output is provided for external metering.

Protection and Diagnostics

Built‑in protections include loss of sensing (shuts down excitation), over‑voltage clamping, thermal shutdown, and reverse polarity protection. A fault relay output provides remote alarm. LED indicators show power, regulation status, and fault conditions. The regulator includes a self‑test function for rapid diagnostics.

Technical Specifications

Sensing input: 120 VAC ±10%, 50/60 Hz. Accuracy: ±0.5%. Response time:<40 ms. Operating temperature: –25°C to +65°C. Enclosure: IP20, panel‑mount. Weight: approximately 2.5 kg. Complies with IEEE 421.5 and CE standards.

Applications

This regulator is used on diesel, gas, and hydro generators from 300 kVA to 3 MVA in standby, prime power, and parallel operation. It is ideal for data centers, hospitals, offshore platforms, and cogeneration plants where voltage stability is critical.

Installation and Commissioning

Mount the regulator in a clean, ventilated panel. Connect sensing leads to the generator output, field leads to the exciter, and auxiliary inputs as needed. Commissioning involves setting the voltage setpoint, stability, and droop while performing load tests. The regulator includes a test mode for excitation checkout without running the generator.

Reliability and Quality

Basler Electric’s SR4A‑2B15B3A is built with industrial‑grade components and conformal‑coated circuit boards for moisture and dust resistance. It undergoes rigorous testing for vibration, temperature cycling, and surge immunity. The regulator has a MTBF exceeding 80,000 hours, ensuring long‑term dependable operation.

Conclusion

The Basler Electric SR4A‑2B15B3A static voltage regulator provides precise, reliable, and high‑current voltage control for generator applications. Its 120VAC sensing input and robust design make it a versatile choice for a wide range of power generation systems.