Compact® NSF and NSJ 150 to 600 A Circuit Breakers

Section 4—Trip Units

Options for

Equipment Ground-fault Protection (T)—see (6) and (7), page 14

Electronic Trip

 

 

 

Type

Residual Current

Unit STR53UP

 

 

 

Tripping threshold

Ig

Adjustable (8 Settings) 0.2–1 x In

 

 

 

 

 

Accuracy

± 15%

 

 

 

 

 

 

 

Tripping time (ms)

Max. overcurrent time before tripping (Tg)

Adjustable (4 Settings + Constant I2t Function) 60, 140, 230, 350

 

Total Breaking Time

-140, -230, -350, -500

 

 

 

 

 

 

Ammeter (I)

06153068

 

 

 

 

 

 

A

In

I1

I2

I3

A digital display continuously indicates the current of the phase with the greatest load. By pressing a scroll button, it is also possible to display successively the readings of I1, I2, I3 and I neutral. LEDs indicate the phase for which the current is displayed.

Zone-selective

A number of circuit breakers are interconnected one after another by a pilot wire. In the event of a

Interlocking (ZSI)

short-time or earth fault:

 

If a given trip unit STR53UP detects the fault, it informs the upstream circuit breaker which applies

 

 

the set time delay

 

If the trip unit STR53UP does not detect the fault, the upstream circuit breaker trips after its shortest

 

 

time delay

 

In this way, the fault is cleared rapidly by the nearest circuit breaker. In addition, thermal stresses on

 

the circuits are minimized and time discrimination is maintained throughout the installation.

Opto-electronic

The use of opto-transistors ensures total isolation between the internal circuits of the trip unit and the

Outputs

circuits wired by the user.

Communication

Transmission of the following data to Digipact® distribution monitoring and control modules:

(COM)

Settings

 

 

Phase and neutral currents (rms values)

 

Highest current of the three phases

 

Overload condition alarm

Possible

I

Combinations

T

 

I + T

 

I + COM

 

I + T + COM

 

ZSI

 

ZSI + I

 

ZSI + T

ZSI + I + T

ZSI + I + COM

ZSI + I + T + COM

© 1995–2003 Schneider Electric All Rights Reserved

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Image 15
Schneider Electric Class 615 dimensions Options for, Electronic Trip