Phase failure sensor with contactor contact monitoring CZF-2B contacts: 1NO, I=10A, 2 modules

Three-phase motor protection – reliable phase failure sensor

This phase failure sensor with contactor contact monitoring is a key element in protecting electric motors powered by a three-phase network. Its task is to monitor the voltage in individual phases and react to dangerous situations, such as voltage loss in one or more phases, voltage asymmetry between phases, and damage to contactor contacts. This minimizes the risk of motor damage and downtime.

CZF-2B is a device mounted on a 35mm rail, occupying only 2 modules, allowing for easy integration with the existing installation. The use of screw connections ensures a secure and durable connection of the wires. Thanks to this, both installers and end-users can count on trouble-free system operation.

Functionality and application

The device effectively protects motors against the effects of power failures and problems with control elements. Designed to work with contactors, it monitors not only the presence of voltage in each phase but also the condition of their contacts. If an irregularity is detected, the sensor immediately reacts, disconnecting the load and preventing more serious damage.

Protection against phase failure is implemented by a quick reaction to the lack of voltage in one or more phases of the power supply network. Additionally, the sensor controls phase asymmetry – detects uneven voltages between phases, which can lead to motor overheating. An important element of functionality is monitoring the contactor contacts that switch on the motor, preventing operation on damaged elements. A quick reaction is guaranteed by a maximum time delay of 4 seconds in the event of a power failure. The device finds application in various industrial and commercial applications requiring reliable protection of electric motors.

Technical specifications and operating parameters

The sensor operates in the voltage range from 140 to 270V AC and has one normally closed contact (1Z) with a maximum current load of 10A. Its compact dimensions (90 mm high and 65 mm deep) make it easy to install even in limited space. The device does not require an external power source, which simplifies installation and reduces operating costs. It is important that the sensor has a fixed time delay at the level of 4 seconds – it is not adjustable by the user. This ensures consistent device operation in various working conditions.