FF phase loss and asymmetry relay CZF-B 10A 1NO 4s 55V

FF CZF-B is a phase loss and phase asymmetry protection relay designed to monitor three-phase electrical supplies. It detects phase loss, phase reversal and phase imbalance to prevent damage to motors and other three-phase equipment. The device provides a single normally open contact with a rated switching current suitable for control circuits and protection applications. The relay is intended for installation in industrial control panels and building electrical installations where reliable phase supervision is required.

Advantages

The relay offers continuous monitoring of three-phase supplies with a clear, simple contact output that integrates with existing control systems. Its 10 A rated switching current supports common auxiliary and control loads, while the fixed operating delay helps avoid nuisance trips caused by short disturbances. The compact design and straightforward wiring make the unit practical for retrofit and new installations.

Suitable for

• Protection of three-phase motors against phase loss and imbalance
• Supervision of supply integrity in HVAC, pumps and compressors
• Integration into motor starters and control panels
• Building electrical distribution where phase monitoring is required

Key specifications

• Protection functions: phase loss, phase asymmetry, phase reversal detection
• Contact configuration: 1 normally open (1NO)
• Rated switching current: 10 A
• Operating delay: 4 seconds
• Nominal operating voltage: 55 V
• Intended supply type: three-phase systems
• Mounting: panel/rail suitable for control enclosures

How to use

Install the relay in the control panel according to local electrical codes and the wiring diagram provided by the manufacturer. Connect the three-phase supply lines to the appropriate input terminals and wire the single normally open contact into the control circuit that will stop or isolate the protected equipment in the event of a fault. Verify that the nominal voltage and system type match the relay specifications before commissioning. After power-up, test the function by simulating phase loss or imbalance and confirm that the relay operates after the specified operating delay.

Usage recommendations

Use the relay as part of a coordinated protection scheme: combine it with appropriate overcurrent, thermal and short-circuit protection devices and follow manufacturer guidelines for wiring, grounding and environmental conditions. Regularly inspect connections and test the relay operation during maintenance to ensure reliable protection of motors and three-phase equipment.