Modular automatic phase switching relay 3F | 63A | 3x380V | DIN

Technical Specifications
Rated Voltage (Un): 3×380V + Neutral
Operating Frequency: 50/60Hz
Maximum Load Current: 63A
Power Consumption: <6VA
Operating Temperature: -20°C ... +55°C
Overvoltage Setting (U>): 230 – 300V (can be disabled)
Undervoltage Setting (U<): 110 – 210V (can be disabled)
Fault Delay Time: 3 sec. (fixed)
Switching Delay: L1, L2, L3, cyclic mode
Display: 3×3-digit LED display with 6 status LED indicators
Measurement Accuracy: ±1%
Functions and Operating Principle
Automatic Phase Switching
If the voltage of phase L1 exceeds the set threshold (U>) or drops below the set limit (U<), the device automatically switches the load to another available phase after a 3-second delay.
If no suitable phase is available, the relay disconnects until at least one phase returns to normal operation.
Phase Fault Identification
Overvoltage: If the used phase voltage exceeds the set threshold, the relay disconnects the phase and switches to another. The LED display shows an error, and the U> indicator lights up.
Undervoltage: If the phase voltage drops below the set limit, the relay disconnects the phase and switches to another. The LED display shows an error, and the U< indicator lights up.
Cyclic Switching Mode
When the "Cycle" function is enabled, the relay maintains the current phase unless it fails.
If the phase fails, the system switches to another functional phase and keeps it until a new failure occurs.
User Control and Display
The display shows the input voltage and remains steady in normal operation.
In case of failure (overvoltage or undervoltage), the display blinks, and the corresponding LED indicator shows the fault phase.
Control Buttons:
Undervoltage setting button
Overvoltage setting button
Switching delay setting button
General phase setting button
Manual ON/OFF button (disabling automatic operation)
Protection Functions
The device features a self-reset mechanism when at least one phase returns to normal.
Protects connected equipment from overvoltage or undervoltage.
A fixed 3-second delay prevents false switching due to transient voltage fluctuations.
Usage
Application in Industry and Household:
Electrical distribution systems – protects equipment from voltage fluctuations.
Server and IT infrastructure protection – ensures stable power supply.
Industrial sites – prevents unnecessary switching in manufacturing equipment.
Backup power systems – used with generators and UPS systems.
Installation and Connection:
Must be connected according to the electrical diagram; incorrect wiring may damage the device.
A fuse and disconnect switch must be installed nearby for quick emergency shutdown.
Must be mounted in a dry environment to avoid moisture exposure.
Pros
Automatic phase switching – ensures uninterrupted power supply.
High protection against voltage fluctuations – regulates both overvoltage and undervoltage.
LED display and indicators – clear status and error visualization.
Cyclic function – allows phase retention if functioning correctly.
Adjustable voltage thresholds – customizable to electrical network conditions.

Cons
Not suitable for humid environments – may fail due to water exposure.
Fixed 3-sec delay – may be insufficient for sensitive systems.
Requires professional installation – incorrect connection may damage the device.
Works only in three-phase systems – incompatible with single-phase networks.

The automatic phase switching relay is a reliable solution for ensuring uninterrupted power supply. It protects connected equipment from voltage fluctuations, allows configuration of switching settings, and provides clear operational indicators via an LED display. Ideal for industrial and household electrical systems where a stable power supply is crucial.