Modular | Digital | Voltage Monitoring | Phase Sequence Protection Relay | 3x380V | 260-370V | 400-510V | DIN

The device allows adjustment of the undervoltage protection threshold from 260V to 370V AC and the overvoltage threshold from 400V to 510V AC. The trip delay time and reset time can be adjusted from 0.1 to 20 seconds. Integrated phase sequence monitoring prevents the relay output from being activated if the phases of the three-phase network are connected in the wrong sequence.

When the voltage of one or more phases exceeds the preset overvoltage threshold, the HV LED indicator switches on. The device waits for the preset DT time and, if the fault remains present, deactivates the relay output. When the voltage drops below the reset threshold, the RT time countdown begins, and after it expires the relay is activated again.

When the voltage of one or more phases drops below the preset undervoltage threshold, the LV LED indicator switches on. After the preset DT time has elapsed, the relay output is switched off. When the voltage returns to the normal range, the relay is automatically reset after the preset RT time.

In the event of a very large voltage deviation from the rated value, the device has a fast protective disconnection function. In such a case, the relay may be switched off after approximately 100ms without waiting for the normally preset delay time. This helps reduce the effect of dangerous voltage surges on connected equipment.

If the L1, L2 and L3 phase sequence is connected incorrectly, the phase sequence fault LED indicator switches on and the relay output is not activated. This function is particularly important for three-phase motors, pumps, compressors and other equipment whose operation or rotation direction depends on the phase sequence.

• One device monitors both overvoltage and undervoltage in a three-phase network.
• Adjustable undervoltage threshold from 260V to 370V AC.
• Adjustable overvoltage threshold from 400V to 510V AC.
• Integrated phase sequence protection helps prevent incorrect rotation direction of three-phase motors.
• Separate adjustment of trip delay and reset time from 0.1 to 20 seconds.
• Automatic relay reset when network parameters return to the normal range.
• Fast protection against critical voltage deviations.
• LED indicators allow quick identification of the reason for protection activation.
• Standard DIN rail mounting in control and distribution panels.

• For 3P3W systems only: this version is designed for three-phase three-wire networks and does not use a neutral conductor.
• Limited relay contact load: the output contact is rated for up to 5A / 250V AC resistive load, so a contactor must be used for higher loads.
• Not intended for damp environments: the device must be installed in a dry or suitably protected electrical panel.
• Incorrect phase sequence blocks the output: the relay will not be activated until the phase order is correct.

In an industrial system, a three-phase 380V AC electric motor is controlled through a contactor. This voltage monitoring relay is installed in the control panel. The undervoltage threshold is set, for example, to 330V, the overvoltage threshold to 440V, the DT trip delay to 2 seconds and the RT reset time to 5 seconds. When all phase voltages are within the preset range and the phase sequence is correct, the relay output allows the contactor to operate. If the voltage drops below 330V, rises above 440V or the phase sequence becomes incorrect, the relay output switches off and the motor is disconnected. When the network parameters return to normal, the relay automatically restores operation after 5 seconds.

The relay is designed for a three-phase 3P3W, 3x380V AC electrical network without a neutral conductor.

Yes. The undervoltage protection threshold can be adjusted from 260V to 370V AC.

Yes. The overvoltage protection threshold can be adjusted from 400V to 510V AC.

The DT trip delay can be adjusted from 0.1 to 20 seconds.

The RT reset time can be adjusted from 0.1 to 20 seconds.

Yes. If the phase sequence is incorrect, the relay output is not activated and the corresponding LED indicator shows the fault.

No. When the network parameters return to the normal range, the relay automatically restores the output after the preset RT time.

The relay output contact is rated for up to 5A / 250V AC resistive load, so for a three-phase motor it is recommended to use the relay output to control the contactor coil.

Use the device according to its intended purpose and the supplied electrical wiring diagram. Do not use it in a damp environment. Provide a separate switch and automatic circuit breaker in the installation circuit. They must be installed near the device, in a location easily accessible to the operator, and clearly marked as means for disconnecting the device from the power supply.

Before performing maintenance or cleaning, switch off the device power supply and disconnect it from the electrical circuit. Clean the housing with a soft, dry cloth. Do not use conductive materials, aggressive chemical cleaners or solvents that could damage the device. After cleaning, check that the relay operates correctly.