Product Details:

Voltage TypeAC
Voltage (V)220/380 – 240/415
Number of Poles4 Pole
ApplicationThree Phase Voltage & Neutral Monitoring
Current (Amps)5A @ 250V AC
Contact FormDPDT (2NO + 2NC)
TypeUndervoltage, Overvoltage, Phase loss, Phase Imbalance, Reverse phase sequence, Neutral break protection

RNPP-312 has been designed:

  • for monitoring the permissible voltage level;

  • for monitoring the correct alternation and absence of sticking of phases;

  • for monitoring the full-phase and symmetry of the mains voltage (phase imbalance);

  • to disconnect the load in case of improper mains voltage and neutral failure;

  • for monitoring the quality of the mains voltage after switching off the load and automatically turning it on after restoring the voltage parameters;

  • to indicate the failure in the event of emergency situation and the presence of voltage in each phase.

The device provides the possibility of adjusting the parameters (voltage threshold, time of automatic reclosing and time delay of protection operation), selection of the voltage of the monitored mains (400 V or 415 V) and a set of protective functions. After restoring the voltage parameters of the mains, the device enables again the load after the reclosing time.

RNPP-312 can be operated in the following modes:

  • “Minimum and maximum voltage control”;
  • “Minimum voltage control”;

  • “Maximum voltage control”;

  • “Phases presence control” (Single Phasing);

  • “Control of incorrect phase sequence; 

  • “Presence of phase sticking” (short circuit);

  • “Phase imbalance/assymetry control”.

Protections can be turned ON/OFF through built-in DIP switch.

The failure is displayed in order of priority:

1 – Phase failure or voltage drop below 100 V (highest priority);

2 – Phase sequence;

3 – Minimum and maximum voltage;

4– Phase imbalance.

Additional Information:

  • Item Code: RNPP-312
  • Port of Dispatch: New Delhi, India

Basic Technical Specifications:





Rated line / phase supply voltage, V

400 / 230, 415 / 240


Mains frequency, Hz

45 – 65


Harmonic composition (unsinusoidality) of supply voltage

EN 50160


Control range of response threshold for Umax/Umin, as a percentage of rated voltage

5 – 50


Control range of protection operation time, s

0 – 10


Control range of AR time, s

0 – 600


Fixed delay of minimum voltage response, s



Response time when one phase breaks, max., s



Readiness time when power supply voltage is supplied, max., s



Phase imbalance determination value, V



Hysteresis of voltage, V

5 – 6


Hysteresis of phase imbalance, V

5 – 6


Accuracy of determination of the voltage operation threshold, max., V



Voltage when maintaining serviceability:

                     – for one phase, V

                     – for three phases, V


95 – 450

95 – 450


Power consumption (when load is connected), max., W



Maximum switching current of output contacts, A



Commutation life of output contacts:

– under load of 5 А (cos φ = 1.0), min., time

– under load of 1 А (cos φ = 1.0), min., time


100 thousand

1 million


Device service

Switchgear and controlgear


Rated operating condition



Protection class rating of the front panel



Protection class rating of the terminal block                        



Electric shock protection class



Climatic design version

NC 3.1


Permissible contamination level



Overvoltage category



Rated voltage of insulation, V



Rated impulse withstand voltage, kV



Conductor cross-section for connecting to terminals, mm²



Tightening torque of the terminal screws, N*m



Weight, max., kg



Overall dimensions (Fig. 1), H*B*L, mm                                                                           



The device installation (mounting) is on standard 35 mm DIN-rail.


The device remains operational capability in any position in space.

Housing material – self-extinguishing plastic



 When the input voltage drops below Umin, the fixed operation time of the device is 12 seconds, if the switches Umax and Umin are in the “ON” position. With any other combination of switches Umax and Umin, the device will operate after the delay time set by the User with Тoff(sec) control. If during this time (12 seconds) the mains parameters change, for example, at the maximum voltage, the device will operate at the smallest of the periods – after the delay time specified by the User, or after the time remaining of 12 seconds.

**  When working in “Maximum Voltage Control” mode, the ready time is 0.3 seconds.



The device meets the requirements of the following:

  • EN 60947-1;
  • EN 60947-6-;
  • EN 55011;
  • IEC 61000-4-2.

Harmful substances in amounts exceeding maximum permissible concentrations are not available.