Specifications

12
COMPACT
®
NS circuit breaker
COMPACT
®
NS circuit breaker: functions and characteristics
Trip units
Options for electronic trip unit STR53UP
Type residual current
Tripping threshold Ih adjustable (8 settings)
0.2 to 1 x In
accuracy ± 15%
Tripping time (ms) maximum overcurrent adjustable (4 settings +
time before tripping function "I
2
t=Cst")
60 140 230 350
total breaking time ≤ 140 ≤ 230 ≤ 350 ≤500
Ammeter (I)
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.
A number of circuit breakers are interconnected one after another by a pilot wire.
In the event of a 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, the
thermal stresses on the circuits are minimized and time discrimination is maintained
throughout the installation.
Opto-electronic outputs
The use of opto-transistors ensures total isolation between the internal circuits of the
trip unit and the circuits wired by the user.
Transmission of data to DIGIPACT
®
distribution monitoring and control modules.
Transmitted data:
■ Settings;
■ Phase and neutral currents (rms values);
■ Highest current of the three phases;
■ Overload condition alarm;
E33945
Communication (COM)
Possible combinations
■ I;
■ T;
■ I + T;
■ I + COM;
■ I + T + COM;
■ ZSI;
■ ZSI + I;
■ ZSI + T;
■ ZSI + I + T;
■ ZSI + I + COM;
■ ZSI + I + T + COM.
Zone-selective interlocking (Z)
"Ground-fault" protection (T) (see (6) and (7), page 11)
A
In I1 I2 I3