NEGATIVE PHASE SEQUENCE VOLTAGE ALARM RELAY/TRANSDUCER
Type VIR310M


The VIR310M is a sensitive negative phase sequence (NPS) voltage alarm relay/transducer with an accuracy of 0.2% NPS, for use in monitoring NPS voltages in 3-wire 3-phase or 3-phase 4-wire supplies where the phase to phase voltage is 110V.

The unit is housed in a size 3 modular case and is based on the VIR43/344 MVFA relays manufactured to Specification EM43 (1990) and EM44 (1990) which are in extensive use by the electricity supply industry throughout the U.K. It is powered from a 48Vdc supply and the burden on the 3-phase supply being monitored is less than 0.1VA total.

The percentage NPS voltage is displayed on a digital LCD panel meter and a 0-12.5mA dc current output proportional to percentage NPS is provided such that 12.5mA is equivalent to 5% NPS voltage. This output can drive a load of between 10 & 1000 ohms and will not be damaged if the load is open or short-circuited.

An alarm output via two sets of changeover contacts is provided and is settable over the range 1 to 8.5% NPS in 0.5% steps with a time delay period of 0 to 150 seconds settable in steps of 10 seconds. Both controls are mounted on the front panel together with a self-resetting LED indicating an alarm condition.

A front panel self-test switch provides a 5mA dc (2% NPS) output current and is displayed on the front panel meter. The alarm output is not affected by the self-test switch.

NGC Approval Reference: TAL 3.9.3.

SPECIFICATION

INPUT VOLTAGE              3 phase 110V rms phase to phase (+15% -20%)
INPUT FREQUENCY         47 - 52Hz.
INPUT BURDEN
Measuring  Supply:          R-Y  0.04VA   B-Y  0.04VA  TOTAL 0.1VA cosų 0.8
SUPPLY                          48Vdc (+25% -10%)
SUPPLY BURDEN            3.2 Watts @ 60Vdc
PERCENTAGE  NPS         The NPS voltage measurement is expressed as
                                      a percentage of the nominal input voltage.
NPS ALARM RANGE         Settable from 1.0 to 8.5% in steps of 0.5%.
                                       Accuracy ±0.2% NPS.
TIME DELAY *                  From 0-150 seconds in multiples of 10 seconds.
                                       Accuracy ±0.2 seconds (crystal controlled).
OUTPUT CONTACTS         Two sets of changeover contacts.
CONTACT RATING               
Power:                              3W max
Current:                            0.25A max
Voltage:                           175V dc max
Carry current:                   1A max
OUTPUT INDICATION        Self resetting LED indicator - illuminated during
                                        an alarm condition.
TRANSDUCER OUTPUT *   0-12.5mA dc corresponding to 0-5% NPS.
                                        Accuracy ±0.2% NPS.
                                        Output  is open-circuit and short-circuit proof.
DISPLAY                           A three digit LCD panel meter displaying %NPS
                                        with one decimal place.  Accuracy ±0.2% NPS.
SELF TEST                        2% NPS (±0.2% NPS) producing corresponding
                                        outputs to the transducer output and DPM.
                                        (Does not affect NPS Alarm Output.)
HARMONIC DISTORTION    Negligible effect with 5% total harmonic
                                         distortion of the input supply.
ELECTRICAL 
INTERFERENCE                 NGTS 2.13 Class Z.
Note:                                The transducer output protection circuitry is
                                        connected to earth via a  2.2nF 6KV capacitor.
INSULATION                      2KV rms between all input circuits, output
                                        circuits and earth.
ENVIRONMENT                 NGTS 1 Class B.
ENCLOSURE                    The relay is housed in a yellow size 3 modular case.
Dimensions:                      W: 77mm  H: 177mm  D: 244mm.
Weight:                             1.9kg.

* Other TIME DELAY ranges and TRANSDUCER OUTPUT scalings can be supplied to order.

Convex Design Limited

email:sales@convexdesign.co.uk

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