Voltage and phase loss sensor CZF-BS contacts: 1P, I=10A, with signaling 2 modules

Phase failure and asymmetry sensor – protection for motors and installations

This phase sensor, designated CZF-BS, is a reliable device designed to protect three-phase powered electric motors. Its function is to detect voltage loss in one or more phases and voltage asymmetry, which can lead to motor damage. It operates on the principle of a fixed voltage asymmetry threshold, meaning it responds to a specific level of voltage difference between phases.

CZF-BS has a single-pole (1P) changeover contact with a current capacity of 10A, allowing direct control of the motor power circuit. The device is mounted on a 35 mm rail and occupies 2 module spaces, making it easy to integrate into existing electrical installations. Screw connections ensure secure and durable electrical connections.

Application and benefits

• Motor protection: Protects motors from damage caused by phase failure or voltage asymmetry – this is crucial for maintaining production continuity and avoiding costly repairs.
• Preventing downtime: By detecting power supply problems, the sensor prevents the motor from starting in dangerous conditions, preventing failures and downtime.
• Automatic reset: When normal power conditions are restored (voltage increases by 5V above the trigger threshold), the device automatically resets, allowing the motor to restart without operator intervention.
• Versatility: Can be used in installations with a voltage of 3 × 400 V + N.
• LED indication: Built-in LEDs indicate the device's operating status (power supply), making diagnostics and control easier.

Construction features and operating parameters

The device is characterized by a shutdown delay of 4 seconds. This delay minimizes the risk of accidental motor disconnection during momentary voltage drops, which is particularly important in sensitive applications. The voltage asymmetry trigger value is 55V, and the voltage hysteresis is 5V – these parameters ensure precise and reliable detection of power supply problems. CZF-BS does not require an external power source, simplifying installation and reducing operating costs. The voltage measurement range is from 140 to 270 V. The device operates at temperatures from -25°C to 40°C and has a protection class of IP20.