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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 Instantaneous(I) Curves
Instantaneous Trip at High Fault Currents
Notes:
1. Fixed High Instantaneous Trip function is provided in the circuit breaker for Series IZM97 set to pickup at 90kA.
Instantaneous peak current level. The tolerance is 100% ±10% as the pickup points.
2. The peak current level setting for IZM99 is fixed at 176kA.
3. This protection is functional even when the Instantaneous is set to the OFF position.
4. The PXR will light the Instantaneous LED for a High Instantaneous trip.
5. The total Instantaneous clearing times shown are conservative and consider the maximum response times of the trip unit, the circuit breaker opening,
and the interruption of the current under factors that contribute to worst case conditions, like:
maximum rated voltages, single phase interruption, 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.
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Time in
Sec
onds
Instantaneous Asymmetrical Peak Current (kA)
90kA
176kA
