Automatic phase failure switch with adjustable upper and lower voltage thresholds PF-421-TRMS

Automatic phase switch – reliable power supply and installation protection

This automatic phase switch PF-421-TRMS is a device designed to ensure the continuity of power supply to single-phase receivers in the event of a phase failure or a voltage drop below the norm. Its construction based on the measurement of the true RMS value of the voltage guarantees stable operation even in networks with disturbances, making it an ideal solution for both installers and end users. The device finds application in places where power outages can cause serious problems – from single-family homes, through workshops, to commercial facilities.

Functionality and operating parameters

The PF-421-TRMS switch works with three-phase 3×230 V+N networks and offers adjustable operating thresholds – lower in the range of 160÷220 V and upper 240÷280 V. This allows for precise adjustment of the device to specific working conditions and protection of connected devices against incorrect voltage. The maximum AC-1 load current is 16 A, and the switching time does not exceed 200 seconds. The built-in actuator is three relays, and the sampling frequency of the signal is 4 kHz, which ensures a quick and accurate response to voltage changes. Hysteresis of 10 V prevents oscillations and ensures stable operation.

Installation and practical application

The device is mounted on a standard TH-35 rail and occupies only 2 modules (35 mm), which allows you to save space in the electrical cabinet. Screw terminals with a cross-section of 4.0 mm² provide a secure connection of the wires, and the tightening torque is 0.5 Nm. The indication of input voltages using three LEDs facilitates diagnostics and monitoring of the device's status. It is important to remember that the switch does not work with generators. Thanks to its compact size and ease of installation, the PF-421-TRMS is an ideal solution for both new installations and modernization of existing power supply systems.