Magnum
36
1812.900A
3.8 Accessory
devices
A variety of accessory devices are available for use with
Magnum 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.
Magnum circuit breaker accessories are designed to fit all
frame sizes. The accessories fall into one of three
categories:
•
Plug-in electrical
•
Internal electrical
•
Mechanical
3.8.1
Plug-in electrical accessories
There are four Magnum 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 (Figure 3-31). 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
Shunt Trip - The shunt trip is an optional device on circuit
breakers (Figure 3-32 and Figure 3-33). It opens the
circuit breaker instantaneously when its coil is energized
by a voltage input (Table 3-3). A total of two shunt trips
can be mounted on a Magnum circuit breaker.
Table 3-3: Shunt Trip Ratings
Control
Voltages
Operational
Voltage Range 70-
110%
Inrush Power
Consumption
1
Opening
Time (ms)
24 Vdc
17-26 Vdc
250 W
35
48 Vdc
34-53 Vdc
250 W
35
110-125 Vdc
77-138 Vdc
450 W
35
220-250 Vdc
154-275 Vdc
450 W
35
110-127 Vac
77-140 Vac
450 VA
35
208-240 Vac
146-264 Vac
450 VA
35
1
Required for less than 35 ms
Figure 3-31: Through-the-Window Electrical Accessories
1. Accessory Viewing Windows
Figure 3-32: Shunt Trip with Cutoff Switch
Figure 3-33: Shunt Trip Switch Installed
1
