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18/98 IZM circuit-breakers, IN switch-disconnectors
Selectivity: incoming circuit-breaker, outgoing circuit-breaker
2010 CA08103002Z-EN
www.eaton.comSelectivity: incomingcircuit-breaker,outgoingcircuit-breaker
I
n
: Rated operational current
I
u
: Rated uninterrupted current
I
cu
: Rated short-circuit breaking capacity
I
i
: Set value non-delayed short-circuit release
Selectivity 415 V AC
between circuit-breakers enables the
separate isolation of faulty system
sections.
Selectivity exists between incoming
circuit-breaker 1 and outgoing circuit-
breaker 2 if, only outgoing breaker 2 trips
at position 2 during a short-circuit.
System sections 3 and 4 remain
operational.
Selection:
Provided that the short-circuit current does not exceed
those values specified (I
cc rms
).
These details represent the limits of selectivity.
Both circuit-breakers will switch off with higher
short-circuit currents.
On IZM circuit-breakers with V, U, P releases, the delay
time t
sd
must be at least 100 ms longer than the delay
time of the next downstream levels (2, 3, 4).
Incoming circuit-breaker IZM...40-V
IZM...40-U
IZM40...-P
I
n
[A]
4000
4000
4000
4000
4000
4000
I
cu
[kA]
85
100
85
100
85
100
I
i
[A]
48000
48000
48000
48000
48000
48000
Outgoing circuit-breaker (2)
I
u
[A]
I
cu2(415V)
[kA]
N
H
N
H
N
H
Prospective short-circuit current (I
cc rms
in kA)
NZMB(C)(N)(H)1-A(M)…
20
25 - 100
T
T
T
T
T
T
25
25 - 100
T
T
T
T
T
T
32
25 - 100
T
T
T
T
T
T
40
25 - 100
T
T
T
T
T
T
50
25 - 100
T
T
T
T
T
T
63
25 - 100
T
T
T
T
T
T
80
25 - 100
T
T
T
T
T
T
100
25 - 100
T
T
T
T
T
T
125
25 - 100
T
T
T
T
T
T
160
25 - 100
T
T
T
T
T
T
NZMB(C)(N)(H)2-A(M)(V)…
20
25 - 150
T
T
T
T
T
T
25
25 - 150
T
T
T
T
T
T
32
25 - 150
T
T
T
T
T
T
40
25 - 150
T
T
T
T
T
T
50
25 - 150
T
T
T
T
T
T
63
25 - 150
T
T
T
T
T
T
80
25 - 150
T
T
T
T
T
T
90
25 - 150
T
T
T
T
T
T
100
25 - 150
T
T
T
T
T
T
125
25 - 150
T
T
T
T
T
T
140
25 - 150
T
T
T
T
T
T
160
25 - 150
T
T
T
T
T
T
200
25 - 150
T
T
T
T
T
T
220
25 - 150
T
T
T
T
T
T
250
25 - 150
T
T
T
T
T
T
300
25 - 150
T
T
T
T
T
T
NZMC(N)(H)3-A(M)(V)…
220
36 - 150
T
T
T
T
T
T
250
36 - 150
T
T
T
T
T
T
320
36 - 150
T
T
T
T
T
T
350
36 - 150
T
T
T
T
T
T
400
36 - 150
T
T
T
T
T
T
450
36 - 150
T
T
T
T
T
T
500
36 - 150
T
T
T
T
T
T
630
36 - 150
T
T
T
T
T
T
NZMN(H)4-A(M)(V)…
550
50 - 100
T
T
T
T
T
T
630
50 - 100
T
T
T
T
T
T
800
50 - 100
T
T
T
T
T
T
875
50 - 100
T
T
T
T
T
T
1000
50 - 100
T
T
T
T
T
T
1250
50 - 100
T
T
T
T
T
T
1400
50 - 100
T
T
T
T
T
T
1600
50 - 100
T
T
T
T
T
T
Notes
B = Basic switching capacity, N = Normal switching capacity, H = High switching capacity, T = Total selectivity
2
1
3 4
IZM40...