Specifications
11
COMPACT
®
NS circuit breaker
Trip units for COMPACT
®
NSJ400 and NSJ600 circuit breakers
Electronic trip unit STR53UP
E21004
E36298
Protection
Other functions
Overload indications (%Ir)
■ LED goes on when the current exceeds 0.9 Ir;
■ LED flashes when the current exceeds the long-time threshold Ir.
Fault indications
LEDs indicate the type of fault that caused tripping:
■ Overload (LT protection) or abnormal component temperature (>Ir);
■ Short-circuit (ST or instantaneous protection) (>Isd);
■
Ground-fault (if earth-fault protection option is present) (>Ig);
■ Microprocessor malfunction (both (>Ir) and (>Isd) LEDs go on, plus the (>Ig) LED
if the ground-fault protection option is present).
LEDs are battery powered. Spare batteries are supplied in an adapter box. When a
fault occurs, the LED indicating the type of fault goes off after about 10 minutes to
conserve battery power. The information is, however,stored in memory and the LED
can be re-illuminated by pressing the battery/LED test pushbutton (9). The LED
automatically goes off and the memory is cleared when the circuit breaker is reset.
Test
■ Test connector in front (8) for connection to a mini test kit or calibration test kit
(see page 13) to check circuit breaker operation after fitting the trip unit or other
accessories;
■ Test button (9) for (%Ir), (>Ir), (>Im) and (>Ig) LEDs and battery.
Self-monitoring
The circuit breaker trips for:
■ Microprocessor faults;
■ Abnormal temperatures.
Trip units
COMPACT
®
NS circuit breaker: functions and characteristics
■ LT (long-time) overload protection, adjustable threshold, based on the actual rms
current, as defined by IEC 947-2, appendix F:
❑ Adjustable threshold (1) using six lo base settings (0.5 to 1), and fine adjustment Ir
with eight settings ranging from (0.8 to 1);
❑ Adjustable tripping time (2);
■ ST (short-time) short-circuit protection:
❑ Adjustable threshold Isd (3);
❑ Adjustable time delay (4), with or without constant I
2
t function;
■ I (instantaneous) short-circuit protection, adjustable threshold (5).
> Ih
> Im
> Ir
µ P
faulttest
STR 53 UP
Io
x In
-
test
+
3
1 2 4 5
(s) @ 6 Ir
.3 .3
.2
.1
0
.2
.1
0
on
I
2
t
off
.90 .93
.95
.98
1
.88
.85
.8
.8
.9
1
.7
.6
.5
1
.5
.6
.7
.8
1
.4
.3
.2
x Io
Ir
Isd
x Ir
Ii
x In
Ig
x In
tr
tsd
(s)
.4 .4
.3
.2
.1
.3
.2
.1
on
I
2
t
off
tg
(s)
%Ir >Ir >Isd >Ig
A
In I1 I2 I3
IsdIr li
tr
tsd
8
6
79
8
8
4
2
0,5
4 5
6
7
7
3
2
1.5
4 6
8
9
9
3
2
1.5
2
4
5
Ir Isd
3
I
I
t
0
1
7
6