34
Operation and maintenance of
IZM low voltage air circuit breakers
MOELLER
www.moeller.net/de/support
10/09 AWB1230-1605
Effective October 2009
Accessory devices
A variety of accessory devices are available for use with IZM circuit
breakers. Unless otherwise stated, they are all considered optional
devices in the sense that they are not provided as standard on
a manually operated circuit breaker. Available accessories are
identified here and discussed in general terms. For more detailed
information and/or installation instructions, refer to individual
instruction leaflets dedicated to the accessories.
IZM circuit breaker accessories are designed to fit all frame sizes.
The accessories fall into one of three categories:
•
Plug-in electrical
•
Internal electrical
•
Mechanical
Plug-in electrical accessories
There are four IZM plug-in electrical accessories. Three can be
viewed for identification by name and rating through viewing
windows located in the right front of the circuit breaker (
All four are plug-in type and can be factory installed or field installed.
The four plug-in accessories are:
•
Shunt trip (ST)
•
Spring release (SR)
•
Undervoltage release (UVR)
•
Auxiliary switch (AUX)
Shunt trip
—The shunt trip is an optional device on circuit
breakers (
). It opens the circuit breaker
instantaneously when its coil is energized by a voltage input
(
). A total of two shunt trips can be mounted on a IZM
circuit breaker.
Table 6. Shunt Trip Ratings
Control
Voltages
Operational Voltage
range 70–100%
inrush Power
Opening
Time (ms)
24 Vdc
17–26 Vdc
250W
35
48 Vdc
34–53 Vdc
250W
35
110–125 Vdc
77–138 Vdc
450W
35
220–250 Vdc
154–275 Vdc
450W
35
110–127 Vdc
77–140 Vdc
450W
35
208–240 Vdc
146–264 Vdc
450W
35
a
Required for less than 35 ms.
Figure 43. Through-the-Window Electrical Accessories
Accessory Viewing Windows
Figure 44. Shunt Trip with Cutoff Switch
Figure 45. Shunt Trip Switch Installed
Spring release
—The spring release is an optional device
(
). It remotely closes the circuit breaker when the
coil is energized by a voltage input (
). 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.
otee:
N
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.