Eaton Magnum PXR - Primary Stationary Contact Design

20
User Manual MN013016EN
Effective July 2022
Magnum PXR and Power Defense SB low
voltage power circuit breakers user manual
EATON www.eaton.com
“Toe”
(arcing contact)
“Heel”
(main contact)
Figure 21. Narrow frame (8-finger) moving conductor assembly
“Toe”
(arcing contact)
“Heel” (main contact)
Figure 22. Standard frame (12-finger) moving conductor
assembly
Primary stationary contacts
The primary stationary contact is a combination of two items
(Figure 23). One is a conductive pad mounted on the line conductor
that 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
Breaker
Bottom
Breaker
Front
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x
x
x
x
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x
x
x
x
Line
conductor
Moving contact
fingers
Arc chute
Stationary
main contact
Current
flow
Current
flow
Integral
arc runner
Arcing
contact (toe)
Moving main
contact (heel)
Moving contact
springs
Figure 23. General partial cross-sectional view (shown in
closed position) (not specific to any family/frame)