Three Phase Voltage Monitoring Relay RNPP-312


Three Phase Voltage Monitoring –

Voltage Type AC
Voltage (V) 230/400 – 240/415
Number of Poles 4 Pole, three phase 4 wire system
Application Three Phase Voltage & Neutral Monitoring
Relay output 5A @ 250V AC direct, any current through contactors
Relay Output 1 x DPDT (2NO+2NC), Potential free
Type Under voltage, Over voltage, Phase loss (single phasing), Phase Imbalance, Reverse phase sequence & Neutral break protection


10 in stock


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, V400 / 230, 415 / 240
 Mains frequency, Hz45 – 65
 Harmonic composition (unsinusoidality) of supply voltageEN 50160
 Control range of response threshold for Umax/Umin, as a percentage of rated voltage5 – 50
 Control range of protection operation time, s0 – 10
 Control range of AR time, s0 – 600
 Fixed delay of minimum voltage response, s12*
 Response time when one phase breaks, max., s0.2
 Readiness time when power supply voltage is supplied, max., s0.2**
 Phase imbalance determination value, V30
 Hysteresis of voltage, V5 – 6
 Hysteresis of phase imbalance, V5 – 6
 Accuracy of determination of the voltage operation threshold, max., V3

Voltage when maintaining serviceability:

– for one phase, V

– for three phases, V

95 – 450

95 – 450

 Power consumption (when load is connected), max., W1.2
 Maximum switching current of output contacts, A5

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 serviceSwitchgear and controlgear
 Rated operating conditionContinuous
 Protection class rating of the front panelIP40
 Protection class rating of the terminal blockIP20
 Electric shock protection classII
 Climatic design versionNC 3.1
 Permissible contamination levelII
 Overvoltage categoryIII
 Rated voltage of insulation, V450
 Rated impulse withstand voltage, kV4.0
 Conductor cross-section for connecting to terminals, mm²0.5-1.5
 Tightening torque of the terminal screws, N*m0.4
 Weight, max., kg0.100
 Overall dimensions (Fig. 1), H*B*L, mm90*17.8*64.4
 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.

Additional information

Weight 0.15 kg

1 pole MCB size (W:18 x H:90 x D:48.8 mm)




DIN Rail


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