41
IZM32 / IN32 low voltage air circuit breaker
MN013017EN May 2022 www.eaton.com
Section 5: Protective characteristic curves
IZM32...V(P)...PXR20/25 Long Delay(L) Curves
L-Protection: I
0.5
t-Characteristic curve
.01
.02
.03
.04
.05
.06
.07
.08
.09
.1
.2
.3
.4
.5
.6
.7
.8
.9
1
2
3
4
5
6
7
8
9 10
20
30
40
50
60
70
80
90 10
0
1
2
3
4
5
6
7
8
9
10
20
30
40
50
60
70
80
90
100
200
300
400
500
600
700
800
900
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
.1
.2
.3
.4
.5
.6
.7
.8
.9
Time
in
Se
conds
Current in Multiples of Long Delay Pickup (I
r
)
24
4
15
2
7
0.5
10
6
0.1
0.3
0.4
1
4
0.5
Notes:
1. This curve shown as a multiple of the LONG PU setting (I
r
). The actual pickup point occurs at 110% of the I
r
, with ±5% tolerance.
2. SDPU = 1.5x to 10x of I
r
, have 100% ± 10% tolerance.
3. LD Time = 0.5s to 24s, have 100% +0 / -30% tolerance.
4. SD Slope = I²T. The short pickup points have ±10% tolerance. time setting from 0.1s to 0.5s, with steps of 0.1s, except 0.2s.
tolerance is 100% +0 / -30% except 0.1s, has tolerance 100% +0 / -40%.
5. I²
r
time value projected to I²T line will determine the other break point and shape of the curve.
6. If the short delay time is longer than long delay time, the short delay trip time will follow the long time setting.
7. If long delay thermal memory is enabled, trip times may be shorter than indicated in this chart.
9. This curve is for 50Hz, 60Hz applications.
10. These curves are comprehensive for series IZM circuit breakers including all frame sizes, ratings, and constructions.
The total clearing times shown include the response time for trip unit, the breaker opening and the interruption of the current.
