Checking Arc Chutes - Siemens UL 1066 Operating Instructions Manual

23.3

Checking arc chutes

It is recommended that the arc chutes be inspected on a regular basis.The arc splitter plates erode as the result of load breaking. This
constitutes normal wear. The erosion of the arc splitter plates can manifest itself as wear of the plates, a layer of soot, or small spots of
collections of molten metal. In case of heavy wear (severe erosion, large deposits of molten metal, etc), the circuit breaker should be
replaced.
It is also necessary to replace the arc chutes when the circuit breaker's internal contacts are replaced. See
erosion (page 23-10) for evaluation of contact wear, and
contact replacement.
Hazardous voltage.
Will cause death, serious personal injury, or equipment damage.
Turn off and lock out all power supplying this device before working on this device.
High speed moving parts.
Can cause serious personal injury.
Discharge the closing spring before inspection and before carrying out any work on the circuit breaker.
- OPEN the circuit breaker and discharge the closing spring
- Move the circuit breaker into the withdrawn position in the cradle
Replacing the circuit breaker internal contact assemblies (page 23-11)
DANGER
WARNING
 (page 23-2)
 (page 23-3)
Checking contact
for internal
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