Non-neutral phase sequence phase protection relay

FKV-24F Phase Protection Relay

The FKV-24F is a protective relay designed for three-phase motors. It continuously monitors the electrical network to prevent faults caused by anomalies such as phase loss, asymmetry, or incorrect sequence. It is a reliable and robust solution for ensuring safety and operational continuity in industrial installations.
This device monitors the phase-to-phase voltages ( L1, L2, L3 ) and automatically detects abnormal conditions. In case of an error, it disconnects the output relay to protect the installation and the motor.
Among the protective features it incorporates, the following stand out:

• Phase failure
• Incorrect sequence of phases
• Voltage asymmetry between phases
• Overvoltage and undervoltage

The system operates with fixed asymmetry values and requires no complex programming, facilitating quick and easy commissioning. The device continuously monitors all three phases and automatically responds to any anomalies.

Main features:

• Complete protection for three-phase systems
• Automatic fault detection and phase sequencing
• Phase asymmetry control (fixed value)
• Overvoltage and undervoltage protection
• LED status indicators (output, phase error, asymmetry)
• Automatic operation without the need for complex configuration

Technical specifications:

• Supply voltage: 3 x 380V AC + neutral
• Frequency: 50/60 Hz
• Power consumption: <4VA
• Voltage range (U>): 180V – 500V AC
• Asymmetry: ≤ 11%
• Accuracy: ±1%
• Relay output: 5A / 250V AC (resistive load)
• Operating temperature: -20°C to +55°C
• Mounting: DIN rail or panel
• Weight: max. 110 g

Operation is fully automatic: when network conditions are correct, the relay activates. If any anomaly is detected, the device disconnects the output and signals the error via LEDs, automatically restoring operation when the values return to normal.
The FKV-24F is a simple, reliable and effective solution for the protection of three-phase motors, especially suitable for applications where basic protection is required without the need for complex adjustments.