
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24.5
Checking contact erosion
It is strongly recommended that the breaker's internal contacts be inspected on a regular basis. Load breaking and short-circuit trips cause
contact erosion. The WL circuit breaker is equipped with a contact erosion indicator for monitoring wear of the circuit breaker's internal
contacts.
- OPEN circuit breaker the circuit breaker and discharge the closing spring
- Move the circuit breaker into the withdrawn position in the cradle
- Manually charge the closing spring
- Close the circuit breaker
- Remove the arc chutes
View with the circuit breaker closed
(1)
Indicator pin
(2)
Indicator pin is visible in the big recess
(3)
Indicator pin is no longer visible
(4)
Arcing tip
(5)
Arc Chamber
If the indicator pin is no longer visible, the circuit breaker must be replaced.
For the visual inspection of fixed-mounted circuit breakers, use a mirror if required.
-
DANGER
Hazardous voltage.
Will cause death, serious personal injury, or equipment damage.
Turn off and lock out all power supplying this equipment before working on this device.
WARNING
High speed moving parts.
Will cause serious personal injury.
Do not place hands or objects within the arc chamber.
0071-1
(5)
(1)
(2)
(3)
(4)
Summary of Contents for UL 489
Page 36: ...5 21 Frame size II 3000 A Frame size III 1 Holes 14 mm 0720 1 0721_nu ...
Page 63: ...7 2 Horizontal connectors 0733_nu top view ...
Page 64: ...7 3 Rear vertical connectors 0734_nu top view rear view ...
Page 65: ...7 4 Front connectors 0736_nu front view top view ...
Page 66: ...7 5 Front connectors and pressure wire terminals 0737_nu top view front view ...
Page 67: ...7 6 7 2 Frame size II fixed mounted version 0494 3_nu ...
Page 68: ...7 7 Class C always 0494 5_nu top view rear view ...
Page 69: ...7 8 2500 0738_nu LH side view front view ...
Page 71: ...7 10 7 4 Frame size III fixed mounted version 0495 1_nu LH side view ...
Page 72: ...7 11 0495 2_nu top view top view ...
Page 73: ...7 12 0495 3_nu top view rear view ...
Page 75: ...7 14 7 5 Door cut outs fixed mounted circuit breaker Frame size I 0735_nu ...
Page 76: ...7 15 Frame size II III 0496_nu ...
Page 77: ...7 16 7 6 Frame size I draw out version 0745_nu ...
Page 78: ...7 17 0746_nu rear view top view ...
Page 79: ...7 18 0747_nu bottom view ...
Page 80: ...7 19 0748_nu ...
Page 81: ...7 20 0749_nu ...
Page 82: ...7 21 7 7 Frame size II draw out version 0490 1_ul ...
Page 86: ...7 25 7 8 Frame size III draw out version ...
Page 87: ...7 26 ...
Page 88: ...7 27 ...
Page 89: ...7 28 7 9 Door cut outs for draw out circuit breakers Frame size I 0750_nu ...
Page 91: ...7 30 7 11 External sensor for neutral conductor WLNCT2 ...
Page 92: ...7 31 WLNCT3 ...
Page 107: ...9 5 I tripping Ground fault tripping ...
Page 351: ......