21
Instructional Leaflet
IB2C12063H03
Effective March 2012
Instructions for Installation, Operation and
Maintenance of Magnum SB Insulated Case
Low Voltage Power Circuit Breakers
EATON CORPORATION
www.eaton.com
“Toe”
(Arcing
Contact)
“Heel”
(Main
Contact)
Figure 23. Narrow Frame (8-finger) Moving Conductor Assembly
Figure 24. SBSE Moving Contact Assembly
Primary Stationary Contacts
The primary stationary contact is a combination of two items
(
Figure 26
) . One is a conductive pad mounted on the line
conductor which functions as the stationary main contact . The
other is an arc runner, also connected to the line conductor . The
integral arc runner serves a dual purpose:
• Fixed arcing contact
• Part of the arc chute
“Heel” (Main
Contact)
“Toe” (Arcing
Contact)
Figure 25. Standard Frame (12-finger) Moving Conductor Assembly
Figure 26. Partial Cross-Sectional View (Shown in Closed Position)