Feeder Protection/Transformer Backup Protection JNC 268 - L

OVERVIEW

    Features

  • Suitable for 1A / 5A relay rating
  • Choice of 6 IDMT curve and definite time
  • History of 6 latest faults along with settings
  • Self supervision facility
  • Breaker status monitoring
  • In-built breaker trip circuit supervision
  • Disturbance records (DR) in IEEE COMTRADE
    format – Optional
  • Event Records (ER) – Optional
  • Programmable digital inputs and outputs
  • MODBUS open protocol over RS – 485 port
  • MODBUS protocol over RS – 232 port
  • Draw out facility with inbuilt CT shorting

Application:

The relay provides time graded phase, earth fault (2 stage) protection along with 5 shot auto recloser and SCADA capability.

FEEDER PROTECTION / TRANSFORMER BACKUP PROTECTION - (COREL – NII SERIES) JNC 268 - L

Principle of Operation:

JNC 268 N / JNC 268 A / JNC 268 L :

The relay measures the line current from each of the line CTs and if the current exceeds the set threshold, then relay extends a trip signal after an operating time. The relay's “operating time” is determined by selecting “definite time” or one of the six “inverse time” characteristics.

A sensitive earth fault or restricted earth fault (suitable for high impedence REF scheme) is provided in the relay.The input to sensitive earth fault protection can be connected in two ways. First one the residual current derived from three phase current transformers, and second is low output core balance current transformer can be connected. The input to restricted earth fault protection will be derived from neutral CT output with external stabilizing resistor.The relay has facility to monitor circuit breaker operation through 52a or 52b aux contacts of circuit breaker.

4 programmable digital inputs (PDI) and 4 programmable digital outputs are provided and can be used to synthesize logic along with some internal digital inputs i.e.(phase OC pickup, Earth fault pickup, Phase high set trip, Earth fault OC trip, Earth fault high set trip,etc). Together, this feature can be effectively used to reduce the number of aux. tripping relays in a protection scheme. The trip relay (B1-B2) can be operated either when any one / more of the protection scheme provided inside JNC 268 x initiates the relay or any/more of the PDI initiates the same relay.

Each PDO has independent timer. Each PDI has programmable mask facility.The relay in-built breaker trip circuit supervision and dedicated alarm contact to indicate trip circuit failure.

JNC 268 A :

Provides Multi shot auto re-closer facilitates automation of breaker operation. Auto re-closer can be programmed to provide a maximum of five shots. “Dead time” starts when a trip signal is provided due to the occurrence of a fault involving L-L or L-G or L-L-G or L-L-L or L-L-L-G. After an elapse of a time interval equal to “dead time”, closing command will be extended.

The “reclaim time” timer starts at the instant when the “dead time” timer expires. If after extending the “breaker close” signal an over current fault was detected before the “reclaim time” timer reached its terminal count, then the relay understands that the fault in the system is still persisting and the over current relay will issue a trip signal. The relay tries to close the breaker for a maximum of the programmed number of shots before it choses to lockout. The relay can be configured for independent trip sequence as IDMT or Def. time

JNC 268 L :

The relay monitors line current even after the trip condition to ensure breaker operation. Even if small current exist in the line the relay sends trip command to adjacent or backup breaker after definite operating time. The current threshold and definite time required to detect breaker failure are programmable.

 

SPECIFICATIONS

Ratings:

Current rating ( In )

:

1A / 5A ( Site selectable)

Aux. Supply

:

1) 20 to 60V DC
2) 80 to 260V AC / DC

 

 

 

Settings:

Operating characteristics
(Separate for Phase &
Earth fault )

:

1) 3.0s Normal Inverse
2) 1.3s Normal Inverse
3) 1.5s Very Inverse
4) 0.8s Extremely Inverse
5) 0.6s Extremely Inverse
6) 13.3s Long Inverse
7) Definite Time

Phase OC (IDMT)

:

20 to 200% in steps of 5%

Phase OC (Def time)

:

20 to 500% in steps of 5%

Earth fault (IDMT)

:

5 to 80% in steps of 1%

Earth fault (Def time)

:

5 to 100% in steps of 1%

SEF (Def time)

:

1 to 16% in steps of 0.5%

REF (Instantaneous)

:

2 to 80% in steps of 1%

TMS (Ph & E/F)

:

0.02 to 1.0 in steps of 0.01

Definite time (Separate
for Ph, E/F & SEF )

:

Instantaneous to 25.0s in steps of 0.1s

Phase High set

:

100 to 3200% in steps of 100%

Earth fault High set

:

50 to 1000% in steps of 50%

High set operating time
( Ph & E/F )

:
:

Instantaneous to 500ms in
steps of 50ms

Breaker monitoring

:

1) 52a monitoring
2) 52b monitoring
3) None

RS232 communication

:

MODBUS Protocol 9-Pin D
at front end

RS485 communication

:

MODBUS Protocol Isolated
RS485 at rear end

No. of DR (optional)

:

Two

Duration of DR

:

0.86s (0.46s Pre-fault and 0.4s
Post-fault)

ER (optional)

:

120 events

 

 

 

JNC 268 A SETTINGS

Max. Shots (re-closing)

:

Maximum of 5

Dead time 1 to 5

:

0.5 to 250s in steps of 0.1s

Reclaim time

:

10 to 250s in steps of 1s

Cold load pickup (CLP)

:

2 to 16 times the OC (IDMT)

CLP Delay

:

0.05s to 1.0s in steps of 0.01s

     

JNC 268 A SETTINGS :

Max. Shots (re-closing)

:

Maximum of 5

Dead time 1 to 5

:

0.5 to 250s in steps of 0.1s

Reclaim time

:

10 to 250s in steps of 1s

Cold load pickup (CLP)

:

2 to 16 times the OC (IDMT)

CLP Delay

:

0.05s to 1.0s in steps of 0.01s

 

 

 

 

Mechanical Design :

Weight

:

2.5 Kgs.(Approx)

Case Size Fascia

:

144 sq. mm depth 232mm

Installation

:

Flush mounting

Panel cutout

:

138mm x 138mm

     

Accuracy:

Operating value

:

105% to 125%

Operating value
(Definite time)

:

100% to 115%

High set operating value

:

±5%

Drop-off / pick-up

:

Between 70% to 98%

Operating time

:

±5% or ±30ms whichever is higher
±7% or ±30ms whichever is
higher, for 0.8s EI, 1.5s VI &
13.3s LI characteristics.

 

 

 

     

Digital Input & Output

Potential Digital inputs

:

4 Nos ( 50 to 250V DC )

Non-Potential digital

:

4 NO contacts

outputs

:

(5A at 24V DC / 230V AC)

Digital output timer

:

Instantaneous to 25.0s in stepsof 0.1s

     

Contact Ratings:

Trip contact

:

1250VA at maximum 10A or

Make & carry

:

440V AC / 220V DC

Trip contact

:

2300VA at maximum 10A or

Break capacity

:

440V AC / 250V DC

Alarm contacts

:

10A at 24V DC / 230V AC

     

Contact Durability :

Electrical

:

100,000 operations min.

Mechanical

:

1000,000 operations min.

     

Insulation

1. 2 KV RMS, 50 Hz for 1 minute / 2.5 KV for 1 sec.
    Between all terminals and earth.
2. 1KV RMS, 50 Hz for 1 minute across open contacts.

 

Over Load Rating:

Current input

:

2 times rated continuous
20 times rated for 3s
40 times rated for 1s

     

Burden:

Current input

:

0.4VA per phase (Rated 5A)
0.05VA per Phase (Rated 1A)

Aux. Supply

:

Less than 8W (Non operated)
Less than 12W (Operated)

     
 

FEEDER PROTECTION / TRANSFORMER BACKUP PROTECTION - (COREL – NII SERIES) JNC 268 - L

 

DOWNLOADS

FEEDER PROTECTION / TRANSFORMER BACKUP PROTECTION
(COREL – NII SERIES) JNC 268 - L

Catalogues:

DOWNLOAD

Operating Manual:

DOWNLOAD

 

FEEDER PROTECTION / TRANSFORMER BACKUP PROTECTION - (COREL – NII SERIES) JNC 268 - L

 

ORDERING INFO.

Ordering Information:

Relay type

:

JNC 268 X
N – No ARR and LBB
A – With ARR
L – With LBB

Aux. Supply

:

20 to 60V DC or
80 to 260V AC / DC

In-built protection
element

:

Sensitive earth fault or
Restricted earth fault

 

 

 

 

FEEDER PROTECTION / TRANSFORMER BACKUP PROTECTION - (COREL – NII SERIES) JNC 268 - L

 

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