Production:

Three phase voltage, phase imbalance and phase sequence relays

Three-phase voltage and phase monitoring relays are designed for the protection of the most essential services. They provide cost-effective protection against equipment failure caused by voltage faults on 3-Phase systems, i.e. they are adapted to protect three-phase loads from unallowable variations in the mains voltage, phase loss and phase imbalance, phase “coincidence” and incorrect phase sequence. They are efficiently applicable for the protection of refrigerating and air-conditioning installations, compressor plants and other equipment with an electric motor load. They are also used in the devices that call for continuous monitoring of the mains voltage, three phase lines for quality and voltage presence, e.g. in the automatic throw-over circuit-breakers.
Hysteresis is about 5V in all the relays. The operational capability range is 30 -150% of the nominal voltage. Deep undervoltage (when one or more phase voltage value drops 30 V below the user-preset minimum voltage threshold) and/or abrupt overvoltage (when one or more phase voltage 30V exceeds the user-preset maximum voltage threshold) automatically make the relay to trip with acceleration. The relay will reset automatically activating a load with user-specified time delay on return to normal operating conditions when voltage values regenerated, reaching the level set by hysteresis. The relays are compact, rugged and have a small weight. All the relays are mounted on the standard DIN rail.
The relays are connected in parallel to load and they energize a magnetic starter coil that’s why the relay operation is practically independent on load power. Two groups of independent contacts (one pair is N.C. contacts, another pair is N.O. contacts) at the relay output terminals switch the load up to 5A power.

RNPP-301
Three-phase voltage and phase monitoring relay

This is a microprocessor-based multifunction mains voltage monitor. Developed on the base of modern microprocessor technology the device is offering the unique set of services that is able to replace several traditional devices.
RNPP-301
The RNPP-301 monitor provides:
  • full multi-fault protection;
  • an additional function of monitoring for the magnetic starter power contacts switch (position at no-load and under load);
  • an unique option of two control modes that can be selected as phase or line voltage monitoring;
  • monitoring of the tolerable RMS phase/line voltage level and tripping for RMS voltage;
  • independent setting adjustments for the minimum/maximum voltage thresholds;
  • monitoring of the correct phase sequence and phase “non-coincidence” (the phases are supposed to be coinciding when a load is energized not from two different phases but instead from one and the same phase);
  • monitoring of three phase lines for voltage presence and the mains voltage symmetry with phase imbalance adjustable setting;
  • the load (380V/50Hz) de-energization after user-set trip delay (Toff) has expired through the opening the magnetic starter coil power curcuit (A.C and D.C. electric curcuit switching) when fault conditions occur;
  • the mains voltage quality monitoring after the relay had tripped and did reset automatically with the user-set reset delay (Ton) upon the voltage parameters regeneration;
  • fault conditions are displayed by special LEDs indicating the specific cause of the occurring mains voltage fault;
  • the LED is provided indicating that the magnetic starter power contacts didn’t switch;
  • all relay states will be displayed via LEDs: LED indicators show when the relay and the load are on.

RNPP-311
Three-phase voltage and phase monitoring relay

RNPP-311The RNPP-311 is the best-selling product of our company, because it offers the services sufficient for the full mains voltage monitoring, but due to ingenious circuitry solutions it is considerably cheaper than corresponding devices from other producers. This is the monitor with extremely low price, adequate set of functions, wide application, high reliability, few needs in the service, operation simplicity and low power demand.

The RNPP-311 monitor provides:
  • monitoring of correct phase sequence and phase “non-coincidence”;
  • monitoring of 3-Phase lines for voltage presence and the mains voltage symmetry;
  • adjustable trip setting for the minimum/the maximum voltage;
  • load 380V/50Hz de-energization (not throwing on) through the opening the magnetic starter coil power circuit when there are the unallowable mains voltage parameters;
  • different decision-making algorithms for different types of faults that allow to ignore transient starting voltage drops, but enable the relay to trip with acceleration in the event of serious voltage faults;
  • the mains voltage quality monitoring after the relay had tripped and did reset automatically with the user-set reset delay (Ton) upon the voltage parameters regeneration;
  • combined indication for all types of the mains voltage faults and LED indication for voltage presence on each phase.
FEATURES
  • self-powered by the three-phase voltage to be monitored;
  • there are two groups of two-way break-before-make contacts in the output;
  • magnetic starter coil supply circuit and power circuits are conductively isolated;
  • all three phases are monitored individually;
  • voltage signals are digitalized;
  • due to digital technology the adjustable and fixed trip settings of the relay are calibrated quite accurate and don’t depend on environment factors, so the relay doesn’t call for additional adjustments and controller settings;
  • the accurate voltage adjustment over a broad range;
  • the range of adjustable & fixed setting values can be changed at the customer’s request;
  • indication of voltage presence on each phase; indication of tripping on fault conditions;
  • different decision-making algorithms for each type of fault;
  • immunity to transient starting voltage drops that cause nuisance tripping is provided;
  • accelerated load de-energization when there are serious fault conditions;
  • hysteresis for Umax/Umin is within 6-7V;
  • operate capability range is 30-150% of nominal voltage when at least one phase is present;
  • compactness and small weight;
  • mounted on a standard DIN rail;

THE RNPP-311 MODIFICATIONS

At the customer’s RFP we designed two modifications of the RNPP-311 monitor on the base of the standard RNPP-311 model. Due to microprocessor based technology the device circuitry remained almost unchanged; the modifications were made in the program recorded in the microcontroller’s memory.

1. RNPP-311 (U-f) TWO CHANNEL VOLTAGE RELAY

The RNPP-311 (U-f) modification is a two- channel voltage relay designed for usage together with Diesel-generators. The device provides all voltage monitor functions of the standard RNPP-311 and in addition it monitors the mains frequency. The modification is designed to provide load 380V/50Hz de-energization when:

  • there are unallowable voltage fluctuations in the mains that last ³ 0.02 sec, the mains voltage peak asymmetry (phase unbalance), phase loss, incorrect phase sequence and phase “coincidence” occur (U channel);.
  • the mains frequency exceeds/drops below the set range (f channel).

2. RNPP-311 (Megafon) TWO CHANNEL VOLTAGE RELAY

The RNPP-311 (Megafon) is designed to provide 3-phase 380V/50Hz system monitoring and to signalize the phase or phases where normal operating voltage are not present. Unlike the standard RNPP-311 the Megafon doesn’t monitor phase sequence, phase “coincidence” and phase unbalance. It has two independent output channels.

The 1st channel signalizes that there is a complete absence of voltage on all three phases in 380V/50Hz lines and/or that the voltages on all phases fall outside the preset Over/Under trip thresholds.

The 2nd channel signalizes that voltage is not present on any one or two phases in 380V/50Hz lines and/or that overvoltage/undervoltage on these phases occurs greater than the trip settings.
All rights reserved. All material on the site is the property of the «Novatek-Electro» Ltd.Design from “Is.Design”,2003 y.