Eaton Magnum Power Defense SB, Руководство пользователя

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48
User Manual MN013016EN
Effective July 2022
Magnum PXR and Power Defense SB low
voltage power circuit breakers user manual
EATON www.eaton.com
Primary contact inspection
Table 16. Pre-inspection conditions
Device Position of poles Mechanism Device position in cassette
Fixed Open Closed Charged Discharged — — — —
Drawout Open Closed Charged Discharged Connected Test Disconnected Removed
Procedure
ote: N Using the mating line of the housing halves as a reference guide will
assist in this visual inspection .
1. With the arc chutes removed, look directly down into the arc
chamber ( Figure 77 ), and visually inspect each primary contact
structure for signs of wear and/or damage .
2. Use the contact wear indicator to inspect each contact . The
contact wear indicator is the relative position of the individual
contact fingers to a narrow, side-to-side ledge inside the arc
chamber . The ledge is actually part of the arc chamber . When
the circuit breaker is closed and the contacts are in good
condition, the narrow ledge is covered by the back end of each
of the contact fingers ( Figure 78 ) . If the back end of any of the
contacts are below the ledge, the contact assembly should be
replaced .
3. Once the inspection is complete, be sure to verify the arc chutes
are properly replaced as previously described in the Arc Chute
Inspection procedure .
m WARNING
ARC CHUTES MUST BE SECURED PROPERLY IN PLACE BEFORE A CIRCUIT
BREAKER IS INSTALLED IN A CIRCUIT BREAKER COMPARTMENT. FAILURE
TO DO THIS COULD RESULTS IN EQUIPMENT DAMAGE, BODILY INJURY, OR
EVEN DEATH.
Figure 77. Primary contacts with circuit breaker open
(not used for contact wear inspection)
Arcing contact
(toe)
Integral
arc
runner
Stationary
main contact
Moving
main contact
Side view
Figure 78. Contact inspection area with circuit breaker open