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NUMERICAL OVER CURRENT AND EARTH FAULT RELAY

PNA SERIES IEEE Device Code - 50, 51, 50N, 51N

Features Three phase, low-set, non directional Over current relay with inverse definite minimum time (IDMT) or definite time characteristics Three phase, high-set, non directional Over current relay with instantaneous or definite time function F Low-set non directional Earth fault Relay with inverse definite minimum time (IDMT) or definite time characteristics F High-set non directional Earth Fault Relay with instantaneous time or definite time function F Modular Integrated Draw Out System for field adaptability and tropicalised design (MIDOS) F Password protection F 2 line 16 characters industrial grade LCD with backlit module for numerical display of setting values and measured values which is user friendly F Trips for default/previously selected curve if the fault occurs during settings of the relay F Membrane key pad for easy operation, dust proof front panel F Enabling /Disabling of High Set F LED indications for power, pick up, phase fault trip or Earth Fault trip for IDMT and High-set F RS-485 communication port with modbus protocol F Relay test facility with relay trip & without relay trip F Separate heavy duly output contacts provided for time delayed phase fault with high-set and time delayed Earth Fault with high-set F Choice of 7 Inverse Time Characteristics Curve, for Phase Fault & Earth Fault Separately Selectable like :F Very Inverse F Normal Inverse F Restricted Inverse F Extremely Inverse F 3 Seconds F 1.3 Seconds F Long Time Delay F Definite time curve for both Phase & Earth along with optional user defined curve. F Low AC burden F Reliable auxiliary supply of wide range input of 18-85V or 85-275 volts AC or DC F Non-Volatile memory for data retention and retrieval in the event of power failure F Unique combination of 50/51/50N/51N in a single gadget F Consistent repeat accuracy F High Drop off/Pick up ratio F Poly carbonate front cover with external reset switch F F

Application The numerical over current and earth fault relay of KP Series PNA TYPE is extensively used for selective short circuit and earth fault protection of radial feeders in solidly earthed, resistance earthed or impedance earthed power systems. It has wide applications in substations & industrial networks. The numerical over current and earth fault relay of PNA TYPE can also be used in most application where inverse time, definite time and instantaneous relays are required. The relay gives selective phase and earth fault protection in time graded systems for transformers, motor etc. If ensures reliable protective system and clears only the faulted section.

Description PNA Type make is a numeric non-directional, combined over-current and Earth Fault Relay or Independent Over Current or Earth Fault Relay. This is intended for protection application in medium-voltage networks. These networks may have isolated or resistance-impedance earthed or solidly earthed neutral points. Definite time over-current relays are both suited for isolated systems and for use as back-up to differential relays and distance relays. Inverse Time Relays (over Current Relays with various inverse time - current characteristics) are advantageous for inter connected systems and solidly grounded systems. Another tool for reducing the tripping time for faults near the source is to use the added instantaneous (High-Set) feature in the numeric relay. If the fault occurs during the setting of relay, the relay shall operate/trip for the previously selected/default settings. TM

PNA Type Numeric Relay receives the input current signals (phase current and neutral current) via four input current transformers. These signals are galvanically de-coupled, suitably filtered and fed to the micro-controller with in built A/D converter for amplitude calculation and further logical processing (i.e., samples, multiplexed).

The micro-controller continuously monitors the magnitude of the phase current and the neutral current. Whenever the phase current or earth current magnitude exceeds the preset values corresponding line/earth element will pick up and relay will trip after the specific time interval calculated by the selected IDMT curves. Whenever the fault level exceeds the selected high set range, the relay will trip for high set, ignoring the selected IDMT curves. The timer logic is processed and after comparison with set time schedules, tripping signals are issued accordingly. There are two output relays, each out put relay has two change over contacts either for alarm or tripping. The auxiliary supply for the numeric relay is provided by a switch mode power supply unit with input voltage either AC or DC with a wide operating voltage from 18-85 volts or 85-275 volts. And in case of AC, the Power supply is designed operate from 45 hertz to 65 hertz.

http:www.prokdvs.com e-mail:prokdvs@blr.vsnl.net.in


TM

NUMERICAL OVER CURRENT AND EARTH FAULT RELAY PNA SERIES

IEEE Device Code - 50, 51, 50N, 51N

Specifications F

Operating Time Accuracy a. Accuracy Range on IDMT Curve for phase or earth : ± 5% on plug setting range (s) b. Definite Time : ±3% c. Instantaneous Time : Less than 3 cycles

F

Electrical Environment a. High frequency (Damped sine Wave) b. Confirms to IEC 60255-22-1988

: (i) 2.5 K.V. Peak : (Common Mode)For a duration of 2 secs. (i) Between DC Circuit and earth with Relay Operated and non Operated Condition (ii)1.K.V. Peak (Transverse Mode) for a Duration of 2 seconds (iii) Across D. C. Terminals (iv) Across Current Terminals (L1 L2 L3 & E/F in series)

F

Rated AC Current Input Frequency Auxiliary Power Supply Auxiliary Voltage Variation Test

: : : :

F

% Pick up range % Drop off DC Burden

: : :

F

AC Burden

:

F F F

F F

1A/5A 50/60 Hz. 85-275 or 18-85 Volts AC/DC Confirms to IEC 60255-6-1988 Clause 3.2.7 The Auxiliary rated input in 110 Volts AC/DC is subjected to 80% and 110% voltage Variation 105% to 120% of setting value >90% of setting value <5 Watts During non operated condition < 6 Watts During operated condition @ rated current of any setting Confirms to IEC-60255-6-1988 Clause 8 <0.5VA for 5A Relay <0.25VA for 1 A Relay @ Unity power factor and at Rated current on any setting.

Inverse Definite Minimum Time Setting Range

Low - Set Setting Range

Lowest Current

Setting Range

I> Phase

0.5 to 2.0 x In

Ie> Earth

0.05 to 0.8 x In

In Steps of

Time

Setting Range

In Steps of

0.05

t>

0.025 - 1.6

0.005

0.05

te>

0.025 - 1.6

0.005

Instantaneous Time

Setting Time in Sec

In Steps of

High set range

High - Set Setting Range

High-set Current

Setting Range

In Steps of

I>> Phase

2.0 to 30.0 x In

1.0

t>> Phase

0.0 to 1.6

0.1

Ie>> Earth

0.5 to 16.0 x In

0.5

te>> Earth

0.0 to 1.6

0.1

Definite Time Setting Range

Definite Time Setting Range

Lowest Current

Setting Range

In Steps of

Definite Time Range in Seconds

In Steps of

I> Phase

0.5 to 2.0 x In

0.05

0 to 150 Seconds

0.1 Sec

Ie> Earth

0.05 to 0.8 x In

0.05

0 to 150 Seconds

0.1 Sec

http:www.prokdvs.com e-mail:prokdvs@blr.vsnl.net.in


TM

WIRING DIAGRAM FOR PNA 442

1 N/O 3C 5 N/C

I> Ie >

2 N/O I> 4C Ie > 6 N/C

7 N/O 8 N/O I >> 9C 10 C Ie >> 11 N/C 12 N/C 13 +VE

I >> Ie >>

15

16

17

18

19 21

+

14 -VE

20 L1 S1

-

S2

22

S2

24

L2

23

S1

25

S1

S2

26

27

EARTH S1 S2

28

L3

NOTE: FOR SHUNT RELEASE CONNECT C & N/O CONTACTS FOR UV RELEASE OR CONTACTOR COIL CONNECT C & N/C CONTACTS ARE SHOWING IN HEALTHY CONDITION

MECHANICAL DIMENSION OF PNA 442

NOTE: ALL DIMENSIONS ARE IN MM TOLERANCE:- ± 0.1MM

http:www.prokdvs.com e-mail:prokdvs@blr.vsnl.net.in


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