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New generation IZM97, 99 low voltage air circuit breaker instruction manual
MN013010EN February 2020 www.eaton.com.cn
Section 6: Protective characteristic curves
IZM97(99)...V(U)...PXR20/25 Maintenance Mode Curve
Arc-flash Reduction Maintenance Mode for IZM99 up to 4000A
Notes:
1. Nominal reduction values have a tolerance of ±20%.
2. The nominal ARMs trip time is 40ms with auxiliary power supply.
3. The Maintenance Mode feature must be ENABLED via setting Maintenance Mode switch to ON position
remote switch, or communications for these curves to apply.
Maintenance Mode is in use being shown by blue LED.
4. The PXR will light the Instantaneous LED for a Maintenance Mode Trip.
5. The end of the curve is determined by the interrupting rating of the circuit breaker.
6. Curves applies from -20 °C to +50°C ambient. Temperatures above +85 °C will cause over temperature trip.
7. This curve is for 50Hz ,60Hz applications.
8. These curves are comprehensive for series IZM97/99 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.
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2
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7
.01
.02
.03
.04
.05
.06
.07
.08
.09
.1
.2
.3
.4
.5
.6
.7
.8
.9
8
9
10
20
30
40
50
60
70
80
90
100
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10
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50
60
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90
100
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800
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1000
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3000
4000
5000
6000
7000
8000
9000
10000
Time in
Sec
onds
10
8
6
4
2.5
RMS Current (kA)