Technical data
IZMX circuit-breakers, INX switch-disconnectors
Tripping characteristics
CA01305001Z-EN www.eaton.com
63
Tripping characteristics
IZMX16(40)…P… Tripping characteristics for professional protection
Digitrip 1150/1150i - L, S and S with I
2
t Curves
Apply to Series NRX Type IZMX16 (NF) and IZMX40 (RF) circuit-breakers.
Long Delay (I
2
t) & Short Delay Trip (FLAT & I
2
t)
This curve is for 50 Hz or 60 Hz applications.
Notes:
1. This curve shown as a multiple of the LONG PU Setting (I
r
). The actual pickup
point (indicated by rapid flashing of Unit Status LED on the product) occurs at
110 % of the Ir, current, with a ±10 % tolerance.
The SHORT TIME function and the LONGTIME function act independently and
the entire set of LONGTIME curves continue to be active even after the curves
intersect.
2. If Long Delay Memory is enabled, trip times may be shorter than indicated
on this chart.
3. With zone interlocking on Short Delay utilized and no restraining signal, the
minimum SHORT TIME band (0.10 s) applies regardless of the SHORT TIME set-
ting.
4. The SHORT PU points have 100 % ± 10 % tolerance.
5. SHORT SLOPE: FLAT
Tolerance is +0 / -90 ms for all settings except
0.10 s setting is 0.05 to 0.13
0.15 s setting is 0.09 to 0.17
6. SHORT SLOPE: I
2
t
I
2
t slope flattens out at 8 x I
r
for top of band with FLAT time minimum value pre-
vailing for bottom of band.
The tolerance is
+0 / -40 % for settings 0.1 to 0.25
+0 / -30 % for settings 0.3 to 0.50
7. The end of the curve is determined by the interrupting rating of the circuit
breaker.
8. Curve applies from -20 °C to +55 °C ambient. Temperatures above +85 °C of
the Trip Unit cause automatic trip.
Notes The total Instantaneous clearing times shown are conservative and consider the maximum response times of the trip unit, the circuit breaker open-
ing, and the interruption of the current under factors that contribute to worst case conditions, like: maximum rated voltages, single phase interrup-
tion, and minimum power factor. Faster clearing times are possible depending on the specific system conditions, the type of circuit breaker applied,
and if any arc reduction settings are employed.
500
10
20
24
10
4
2
0.50 s
0.6
0.8
9000
8000
800
900
400
4000
2000
600
3000
1000
700
5000
6000
7000
8
9
5
4
30
7
6
100
200
80
90
50
40
300
70
60
1
2
3
0.01
0.5
0.7
0.9
1
0.02
0.08
0.09
0.05
0.04
0.03
0.07
0.06
0.2
0.8
0.9
0.5
0.4
0.3
0.7
0.6
543
6
7
8
9
10
20
30
40 50 60
70
2
1 min
I/I
r
t [s]
2 h
1 h
10000
0.1
1230DIA-133
Adjustable LONG TIME
2-24 s
(+0 -30%) @ 6 x
I
r
with 0.5 s increments
See Note 7
Adjustable LONG PU
0.5 to 1.0 x
I
n
=
I
r
with 0.05 s increments
See Note 1
Minimum
persistence
Adjustable
SHORT TIME
0.1 s to 0.5 s
with 0.05 steps
See Note 5
Adjustable
SHORT PU
2.0 x to 10 x I
r
with 0.5 s increments
8
9
5
4
7
6
2
3
10
t [s]
543
6
7
8
9
10
2
20
30
40 50 60
80
100
I/I
r
1
0.02
0.08
0.09
0.05
0.04
0.03
0.07
0.06
0.2
0.8
0.9
0.5
0.4
0.3
0.7
0.6
0.1
0.10 s
0.20 s
0.50 s
0.01
1230DIA-134
Max clearing time
Break point @ 8 x
I
r
to FLAT
Minimum persistence
for 0.10 s setting
2
Adjustable I
t
response
SHORT
TIME
0.1 to 0.5 s
with 0.05 s increments
See Note 6
IZMX16(40)...P...