Product Details:

Voltage TypeAC
Voltage (V)400 – 415
Number of Poles3 Pole & 4 Pole, three phase 3 wire and 4 wire system 
ApplicationThree Phase Voltage Monitoring (multi-functional)
Current (Amps)5A @ 250V AC
Contact FormDPDT (2NO + 2NC)
TypeUnder voltage, Over voltage, Phase loss, Phase imbalance, Reverse phase sequence & Phase collision protection

RNPP-311M voltage monitoring relay is designed for protection of three phase loads against major types of mains faults, such as:

  • RMS voltage reaching beyond admissible thresholds – over and under voltage
  • Phase loss or Single phasing
  • Phase sequence order violation or reverse phase sequence
  • Phase coincidence or shorting of two or more phases
  • Phase Imbalance or asymmetry

The device performs monitoring of the main circuit parameters and de-energizes (trip) load when the parameters fall beyond specified boundaries.

The front panel LEDs display the following:

  • Presence of true RMS voltage in the mains
  • Load status (On/Off)
  • Type of fault

Adjustment potentiometers allow for setting:

  • Tripping threshold for the minimum/the maximum voltage, (% of the rated voltage)
  • Time delay for load re-energizing (reset) after the circuit parameters recovery
  • Tripping time delay for load de-energizing (trip) in case of all circuit voltage faults

With DIP switches on the device’s front panel the user can select the type of circuit monitored 400 / 415V, and turn on/off monitoring of the following circuit parameters:

  • Phase sequence
  • Phase imbalance or asymmetry
  • Under voltage
  • Over voltage

Corresponding combinations of the RNPP-311M switches allow for functioning in various modes:

  • Mode of circuit voltage comprehensive monitoring
  • Minimum/the maximum voltage monitoring mode
  • Minimum voltage monitoring mode
  • Maximum voltage monitoring mode
  • Phase presence monitoring mode
  • Phase sequence violation and phase coincidence monitoring mode
  • Phase imbalance monitoring mode; and other modes

The phase availability monitoring function is maintained in any position of the switches, including OFF position. The feature of 24V DC online power supply is available (optional).

Documentation for this device

Additional Information:

  • Item Code: RNPP-311M
  • Port of Dispatch: New Delhi, India

Technical Specification:

Rated line/phase voltage, V



Rated frequency, Hz45 – 65
Harmonical configuration (non-sinusoidality) of power supply voltageEN 61000-3-2 (IEC 1000-3-2)
Adjustable range for Umax/Umin, % of nominal value Unom5 – 50
Adjustable Tripping time delay (Toff), sec0 – 10
Adjustable Auto-reset time delay (Ton), sec0 – 600
Fixed time delay for tripping in case MIN voltage fault detected (time delay for Umin), sec12*
Reaction time in case of phase loss, sec (not more)0,2
Readiness time on energizing the RNPP-311M, sec (not more)0,2**
Phase imbalance value, V60
Voltage hysteresis, V5 – 6
Phase imbalance hysteresis, V5 – 6
Accuracy for voltage tripping threshold measurement, V (not more)3
Accuracy for phase imbalance measurement, %  (not more)2
Protection class against electric shock II
Permissible contamination level II
Overvoltage category II
Nominal voltage of isolation, V 450
Operational voltage range, % of rated voltagefrom 50 to 150
Rated impulse withstand voltage, kV2.5
Power consumption (under power load), VA (not more)3.0
Maximal current that output contacts may commutate, A5
Cross-section area of connection terminals, mm²0.5 – 2
Maximum torque of terminal fixing, N*m0.4

Commutation endurance for the output contacts:

– under 5А power load, not less than

– under 1А power load, not less than



Protection degree:

– for the device

– for the terminals



Operational temperature range, °Сfrom – 35 to +55
Storage temperature conditions, °Сfrom – 45 to +60
Weight, kg (not more)0.200
Standard 35 mm DIN rail mounting 
Mounting position as per requirement (arbitrary)

Specification of the Output contacts (1-2-3 and 4-5-6)

Cos ф

Maximal current at ~250VMaximal capacityMaximal AC Voltage

Maximal current

at 30V DC



5 A

2 А

1250 VA

500 VA

400 V

3 А

RNPP-311M complies with requirements IEC 60947-1:2004, ІDТ, ІEC 60947-6-2:1992, ІDT, CISPR 11:2004, IDT, IEC 61000-4-2:2001, IDT.