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2010 CA08103002Z-EN
www.eaton.comIZM circuit-breakers, IN switch-disconnectors
IZM26 tripping characteristics
18/89
IZM26...A(V)(U)(P)
29 For each current > 1.2 × I
r
the tolerance is [±15 %] or [-15 %, +90 ms],
whichever is greater.
This characteristic curve flattens out for smaller time settings
(“TimeDial”: 0.1 to 0.4) at 14 × I
r
and, if the curves overlap, merges with the
characteristic curve for short-term delay I
sd
for larger time settings
(“TimeDial”: 0.5 to 1.0).
The delay of the short-circuit release and the “TimeDial” time setting are
applied independently of each other. The IEC-B (very inverse) character-
istic curve always remains active, even when the lines cross over.
30 With Digitrip 1150 trip unit without ARMS function the ground-fault
protection settings already begin at 0.1 × I
n
.
A Set values for overload protection I
r
B Maximum total opening delay
C Minimum total opening delay
D Set value for long delay t
r
E Set value non-delayed short-circuit protection I
i
F Set values for short-time delayed short-circuit protection with flat
characteristic curve
G The end of the characteristic curve is determined by the type of
application and the switching capacity of the selected switch.
H Setting values for short time delay with i2t characteristic.
I
Available set values for short-time delayed short-circuit protection I
sd
J Short-circuit release for very high currents
KP Set values for short-time delay at I²t characteristic
L Set values for ground fault protection
M Set values for ground-fault protection delay at flat characteristic curve
N Flat characteristic curve for the deceleration time Ground fault protection
O I
2
t characteristic for ground-fault protection delay time
P Set values for ground-fault protection delay with I
2
t characteristic
q Set values for maintenance mode (ARMS):
R5 = max. reduction,
R1 = min. reduction
R Characteristic curve turning point
S Long delay time with 14 x I
r