FF phase loss and asymmetry relay CZF-311 10 A 1P 4 s 40–80 V

FF CZF-311 is a phase loss and asymmetry protection relay designed for monitoring three-phase supplies and protecting motors and three-phase equipment from damage due to phase loss, undervoltage or unbalanced voltage conditions. The relay is rated for 10 A with a single-pole (1P) output and has an adjustable response delay set to 4 seconds. It operates with a supply voltage detection range of 40–80 V, making it suitable for lower-voltage three-phase systems in industrial and commercial control panels.

Advantages

The CZF-311 provides reliable phase presence and asymmetry detection with a compact footprint for panel mounting. Its fixed 4-second response delay helps prevent nuisance trips from short transients while still providing timely protection for connected equipment. Designed for straightforward integration, the device offers clear functional behaviour for protection of motors and control circuits in three-phase systems operating within the 40–80 V detection range.

Suitable for

• Protection of three-phase motors and pumps against phase loss and unbalance
• Monitoring supply presence in industrial and commercial control panels
• Integration in motor starters, contactor control circuits and protection schemes
• Applications with three-phase systems operating within the 40–80 V detection range

Key specifications

• Protection function: phase loss and voltage asymmetry detection
• Rated output current: 10 A (single-pole output)
• Response delay: 4 seconds (adjustable on unit)
• Supply voltage detection range: 40–80 V
• Mounting: panel or DIN-rail compatible enclosure (device for control panels)

How to use

Mount the relay in the control panel according to the manufacturer’s installation instructions and wire the phase inputs and output contact in series with the motor starter or control circuit. Set the response delay to the required value if adjustment is provided, and verify the supply voltage is within the 40–80 V detection range prior to commissioning. After wiring, perform functional tests to confirm correct operation: simulate phase loss and asymmetry conditions and observe that the relay interrupts the controlled circuit within the configured delay.

Usage recommendations

Use the CZF-311 together with appropriate overcurrent and thermal protection devices to provide comprehensive equipment protection. Regularly inspect electrical connections and perform periodic functional testing to ensure continued correct detection of phase loss and asymmetry.