Phase loss and phase sequence sensor CZF-BT contact: 1Z, I=10A, adjustable operating time 0.5-15 sec., 2 modules

Professional three-phase motor protection

The CZF-BT phase loss sensor is an advanced voltage monitoring device designed specifically for protecting electric motors powered by a three-phase network. The device effectively protects the drive from costly damage resulting from voltage loss in at least one phase or voltage asymmetry between phases, which can lead to overheating and permanent winding damage.

Intelligent monitoring and power status signaling

The device is equipped with three-color LEDs that signal the power status of each phase in real time. Correct load power supply is indicated by the uniform illumination of all LEDs. In the event of an anomaly—voltage loss in any phase (the corresponding LED does not light up) or voltage asymmetry above the set threshold (dimmer LED illumination)—the device reacts immediately by disconnecting the protected motor.

The system utilizes an adjustable trip delay from 0.5 to 15 seconds, which effectively prevents accidental motor disconnection during momentary voltage drops. Automatic reconnection occurs when the voltage increases by 5V above the set hysteresis threshold, ensuring stable installation operation.

Operating parameters and electrical compatibility

The sensor operates at a supply voltage of 3×400V + N and withstands a current load of up to 10A. It is equipped with one NO/NC changeover contact, which allows for the connection of visual or audible signaling systems to inform about relay operation. The asymmetry detection range is 40÷80V, and the voltage hysteresis is set at 5V.

The device consumes only 1.6W of electrical energy, operates in a wide temperature range from -25°C to +50°C, and provides galvanic isolation of the contacts for maximum installation safety.

Construction and modular mounting

The relay features a compact two-module design with dimensions adapted to a standard 35mm DIN mounting rail. Mounting is performed by snapping onto the TH-35 rail, ensuring quick installation without the need for tools. The IP20 protection rating guarantees safe access to hazardous parts.

Electrical connections are made via screw terminals for wire cross-sections up to 4.0 mm² with a tightening torque of 0.5 Nm, ensuring secure and durable wire connections. The housing is made of high-quality plastic, guaranteeing long-term operation in industrial conditions.