Numerical Over Flux Relay JNF 020

OVERVIEW

    Features

  • Programmable V/F ratio
  • History of 5 latest relay closing details

Application:

JNF 020 Over flux relay is used in power systems in order to protect transformers and generators against insulation failure and core damage due to over heating under prolonged over fluxing condition. It protects the equipment against abnormal V/F ratios due to system disturbance which can occur during starting, load sheding and shut down conditions.

Numerical Over Flux Relay JNF 020

Principle of Operation:

Over fluxing of a transformer occurs when its flux density exceeds rated density, it is caused when its V/F ratio is greater than that which the manufacture deems it safe. This of course is the case when it is connected directly to the generator i.e, without benefit of an intervening circuitbreaker and the generator’s excitation system is energized while accelerating to operating speed JNF 020 monitors voltage & frequency ratio, when it exceeds the set value it indicates fault and the output relay operates after a set alarm time delay.

 

SPECIFICATIONS

Ratings:

Rated Voltage

:

110V AC
63.5V AC

Frequency rating

:

50Hz

Aux. Supply

:

1) 20 to 60V DC
2) 75 to 150V AC / DC
3) 175 to 300V DC
    185 to 250V AC

 

 

 

Settings:

Alarm setting

:

1.01 – 1.30 V/Hz. In steps of 0.01

Alarm Time delay

:

00.5 – 50.0 secs. In steps of 0.1

I/T Pickup

:

1.02 – 1.50 V/Hz. In steps of 0.01

TMS

:

001 – 100 In steps of 1

Rated voltage

:

105 – 125 V. In steps of 1V

 

 

 

Mechanical Design :

Weight

:

5000 gms. (approx

Case Size

:

152X296 sq mm, depth 250mm

Installation

:

Flush mounting

Panel cutout

:

146 x 264 mm

     

Standard Compliance :

Accuracy Test

:

IEC 60255-3

Insulation Test

:

IEC 60255-5

     

Accuracy:

Voltage

:

±5%

Frequency

:

±0.02Hz

Phase Angle

:

±2%

Operating time

 

±5%

 

 

 

Contact Ratings:

Trip / Alarm

:

10A at 24V DC / 230V AC

     
 

Contact Durability :

Loaded contact

:

10,000 operations minimum

Unloaded contact

:

100,000 operations minimum

     

Over Load Rating:

Voltage input

:

2 times Rated continuous

     

Burden:

AC voltage input

:

Less than 0.1VA

Aux. Supply

:

Less than 4W (Non Operated)
Less than 10W (Operated)

     
 

Numerical Over Flux Relay JNF 020

 

DOWNLOADS

Numerical Over Flux Relay JNF 020

Catalogues:

DOWNLOAD

Operating Manual:

DOWNLOAD

 

Numerical Over Flux Relay JNF 020

 

ORDERING INFO.

Ordering Information:

Relay type

:

JNF 020

Voltage rating

:

110V AC

Aux. Supply

:

20 to 60V DC or

 

:

75 to 150V AC/ DC or

 

:

175 to 300V DC / 185 to 250V AC

 

 

 

 

Numerical Over Flux Relay JNF 020

 

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