Basler UFOV 260A Under Frequency Overvoltage Protective Module
The Basler UFOV 260A is a multifunctional protective module that combines underfrequency, overfrequency, undervoltage, and overvoltage protection in a single compact unit. It is specifically designed for generator and distributed generation systems to ensure stable operation within acceptable frequency and voltage limits, thereby protecting connected equipment and maintaining grid compliance.
Protection Functions
Underfrequency (UF): Trips when system frequency drops below a set threshold.
Overfrequency (OF): Trips when frequency exceeds the upper limit.
Undervoltage (UV): Trips when voltage falls below the minimum acceptable level.
Overvoltage (OV): Trips when voltage exceeds the maximum allowable level.
Each function has independent pickup and time delay settings, allowing custom coordination for specific protection schemes.
Key Features
True RMS measurement for voltage and frequency.
Adjustable setpoints for all four functions.
Definite time delay or inverse time (selectable).
High accuracy: ±0.5 % for voltage, ±0.05 Hz for frequency.
Wide auxiliary supply: 24–250 VDC or 120/240 VAC.
Three output relays (SPDT) with independent assignments.
Front‑panel LEDs for each protection element.
Compact, DIN‑rail mountable housing.
Technical Specifications
Voltage input range: 100–480 VAC (single‑phase or 3‑phase selectable). Frequency range: 45–65 Hz. Burden: 55 VA (maximum). Setpoint range: UV 70–110 %, OV 110–130 % of nominal; UF 45–55 Hz, OF 55–65 Hz. Time delay: 0.1–30 seconds. Operating temperature: -20 °C to +60 °C. The module meets IEC 61000‑4‑5 for surge immunity.
Application Scenarios
The UFOV 260A is essential for generator protection in islanded or grid‑connected modes. It detects abnormal conditions that could lead to generator damage, load imbalance, or islanding. It is also used in co‑generation plants, renewable energy systems, and critical infrastructure where power quality is paramount.
Installation Instructions
Mount the module on a DIN rail inside a control panel. Connect the voltage sensing wires to the appropriate phases using fused leads. The auxiliary supply must be separately fused. The relay outputs are connected to the trip circuit of the generator breaker or to an alarm system. Ensure proper grounding of the module and cable shields.
Setting and Configuration
Using the front‑panel DIP switches and potentiometers, set each protection threshold and time delay. For example, set underfrequency at 57 Hz with a 0.5‑second delay, and undervoltage at 90 % of nominal with a 2‑second delay. The module also allows enabling/disabling each function individually.
Testing and Commissioning
Apply nominal voltage and frequency and verify that all LEDs are off. Gradually reduce frequency to test the UF element; increase to test OF. Adjust voltage with a variac to test UV and OV. Time the delay to confirm accuracy. Record all settings and test results in the commissioning report.
Maintenance
Inspect the module annually for dust and moisture. Check terminal tightness. Re‑test the protection setpoints after any system modification. The module contains no user‑serviceable parts; if faulty, replace the entire unit.
Advantages of Integrated Protection
Using a single UFOV 260A instead of separate frequency and voltage relays reduces panel space, wiring complexity, and overall cost. It also simplifies coordination and reduces the risk of logic conflicts between separate relays.
Compliance
The UFOV 260A is designed to meet IEEE 1547 and UL 1741 for distributed generation interconnection. It also complies with IEC 60255‑1 for measuring relays.
Conclusion
The Basler UFOV 260A Under Frequency Overvoltage Protective Module offers comprehensive protection in a single, reliable package. Its flexibility, accuracy, and robust design make it a preferred solution for modern generator protection requirements.
