Eaton IZM97 Instruction Manual page 29

Spring release—The spring release is an optional device
(Figure 4-4). It remotely closes the circuit breaker when the
coil is energized by a voltage input (Table 4.2). The closing
spring must be fully charged and the trip latch reset (not
held in the tripped position) for the SR to operate. If these
two conditions are not met, the close signal will be ignored
until it is removed and re-applied.
An optional latch check switch (LCS) can also be installed to
delay application of power to the spring release coil until the
circuit breaker is "ready to close. " The LCS will not permit
energization of the spring release until the breaker is fully
charged and the trip latch is reset. Two versions of the LCS
are available. One version is wired internally to the shunt
trip coil control circuit. On the other version, the LCS switch
contacts are brought out through the secondary contacts for
integration into external control schemes.
N ote: Placing the (externally accessible) LCS directly in
series with the ST coil is not recommended as this
will override the "anti-pump" feature of the electrical
charging/closing system.
Figure 4-4 Spring release with optional latch switch
Table 4.2 Spring release ratings
Control Operational voltage
voltages range 70-110%
24 Vdc 17-26 Vdc
48 Vdc 34-53 Vdc
110-125 Vdc 77-138 Vdc
220-250 Vdc 154-275 Vdc
110-127 Vac 77-140 Vac
208-240 Vac 146-264 Vac
 Required for less than 200 ms
New generation IZM97, 99 low voltage air circuit breaker instruction manual MN013010EN February 2020 www.eaton.com.cn
Inrush power Opening

consumption time (ms)
250 W 40
250 W 40
450 W 40
450 W 40
450 VA 40
450 VA 40
Undervoltage release—The undervoltage release is an
optional device on both manually and electrically operated
circuit breakers (Figure 4-5). It opens the circuit breaker
when its supply voltage falls to between 35–60% of rated
voltage. If the release is not energized to 85% of its supply
voltage, the circuit breaker cannot be closed electrically or
manually (Table 4-3).
Auxiliary switch—An auxiliary switch is an optional device
providing remote electrical indication if the circuit breaker is
open or closed (Figure 4-7). Up to three auxiliary switches
can be mounted in the circuit breaker. Each switch has two
normally open ("a") and two normally closed ("b") contacts
for a total of 12 available contacts (Table 4-4).
Figure 4-5 Undervoltage release
Figure 4-6 Shunt trip, spring release, and undervoltage
release installed
Section 4: Accessory devices
25