Microprocessor phase sequence and phase failure sensor CKF-BT-TRMS

Intelligent three-phase motor protection

The microprocessor-based phase sequence and phase failure sensor CKF-BT-TRMS is a reliable device designed to protect three-phase powered electric motors. It protects against the effects of voltage loss in one or more phases, voltage asymmetry, and incorrect phase sequence – factors that can lead to serious motor damage and downtime. Thanks to the use of True RMS measurement, the sensor ensures accurate operation even in networks with disturbances.

Functionality and application

The CKF-BT-TRMS sensor monitors the motor's power supply status, reacting to:

• Phase failure: Shuts down the motor in case of voltage loss in any phase.
• Voltage asymmetry: Reacts to uneven interphase voltages, which may indicate problems in the power supply network.
• Incorrect phase sequence: Blocks motor start-up if the phase sequence is changed, preventing unwanted direction of rotation.

The device finds application in a wide range of electrical installations, including:

• Protection of electric motors in industry and construction.
• Protection of devices sensitive to power supply disturbances.
• Installations requiring high reliability and safety.

Design and operating parameters

The sensor is mounted on a standard 35 mm wide DIN rail and is characterized by compact dimensions (90 mm high, 35 mm wide and 65 mm deep). It is equipped with screw terminals for connecting wires with a cross-section of up to 4 mm². It does not require an external power source. It has a normally open (NO) changeover contact with a maximum load current of 10A. The adjustable range of voltage asymmetry activation is from 40V to 80V, and the shutdown delay can be set in the range of 0.5 to 5 seconds, allowing you to adapt the sensor's operation to the specifics of the protected installation. The voltage measurement range is from 190 to 270 V.