Technical data
IZMX circuit-breakers, INX switch-disconnectors
Tripping characteristics
CA01305001Z-EN www.eaton.com
67
IZMX16(40)…P… Tripping characteristics for professional protection
Digitrip 1150/1150i - I
4
t Curves
Apply to Series NRX Type IZMX16 (NF) and IZMX40 (RF) Circuit Breakers.
Long Delay (I
4
t) & Short Delay Trip
This curve is for 50 Hz or 60 Hz applications.
Notes:
1. This curve is shown as a multiple of LONG PU Setting (I
r
). The actual Pickup
point occurs at 110 % of I
r
, with a ±10 % tolerance.
2. If Long Delay Memory is enabled, trip times may be shorter than indicated
on this chart.
3. In this time region ≤ 0.5 seconds the I
4
T LONGTIME function will flatten out
and be no faster than the Short TIME setting. This is to avoid a notch in graph.
4. The SHORT PU points have conventional 100 % ± 10 % tolerance.
5. SHORT TIME: FLAT only - setting 0.1 s through 0.5 s in .05 s increments. Tol-
erance is +0 / -80 ms of setting except
0.10 s setting is 0.05 to 0.13
0.15 s setting is 0.09 to 0.17
6. The end of the curve is determined by the interrupting rating of the circuit
breaker.
7. Curve applies from -20 °C to +55 °C ambient. Temperatures above +85 °C
cause automatic trip.
8. Minimum persistence refers to the time at which the breaker will not trip for
a given setting.
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
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
0.10 s
0.50 s
5
1
1230DIA-140
Adjustable LONG PU
0.5 to 1 x
I
n
=
I
r
Settings(
I
r
)
with 0.05 s increments
Adjustable SHORT
TIME 0.1 s to 0.5 s
with 0.05 steps
See note 5
See Note 3
Minimum persistence
See Note 8
Adjustable Long TIME
1-5 s
(+10 -40%) @ 6 x
I
r
with 0.5 s increments
See Note 6
Adjustable SHORT PU
2.0 x to 10 x I
r
with 0.5 s increments
IZMX16(40)...P...