GE Gerapid 2607 User Manual page 40

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1
3
Fig. 42 Inspection of the arc chute
6.1.4 Inspection of the contact system
Pay attention to the warnings, Section 1!
A) Remove the arc chute
•
[Fig. 41]. Loosen the clamping sc rews (3) and (4), using
SW5 hexagon wrench and take off the arch chute (1)
from the adapter (2).
B) Remove the arc chute adapter
•
[Fig. 43]. To dismantle the arc chute adapter, loosen
and pull out the four upright screws (1) using SW5 tool.
Pay attention that no screws or washers fall inside the
breaker!
•
[Fig. 43]. Draw aside and lift off both parings of
adapter (2). Then pull out two protective walls (3).
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1
2
Fig. 43 Adapter and protective w alls
40
Fig. 44 Checking the contact system
2
C) Check the protective walls
•
D) Check the arc runners
•
E) Check the arcing contact
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1
G) Install the adapter
•
H) Install the arc chute
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Design and specifications are subject to change without notice
[Fig. 44]. The material burn out on the protective walls
(5) shall not exceed 1 mm [0.04 in] at any place.
[Fig. 44]. The arc runners should not be burned more
than 30 % of its total cross section. Pay particular at-
tention to the area around arc runner bend (3) and at
contact point with arcing contact (2).
[Fig. 44]. Wear of the arcing contact (1) must not ex-
ceed 2 mm [0.08 in] of its depth. Replace the arcing
contact in that case. If contact erosion exceeds 4 mm
[0.16 in], major contact sy stem f ailure is possible.
F) Check the main contacts
[Fig. 44]. T he main contacts (4) shall not show any par-
ticular signs of material erosion, since the arc is ig-
nited between the arcing contacts. It means, that for
rated and overload currents there should be no ero-
sion of main contacts.
Erosion of main contacts can take place only in case
of excessively worn, highly burned arcing contact or
during very high short circuit currents. In that case
wear must not exceed 1. 5 mm [0.06 in].
[Fig. 43]. Install the two protective walls (3). Use new
ones if necessary. Install two parings of adapter (2)
and tighten screws (1) use 10 Nm [88 in-lbs].
[Fig. 41]. Put arc c hute (1) into adapter (2).
[Fig. 41]. Tighten front and backside connections of
the arc runners (3), including lock washer; use 10 Nm
[88 in-lbs].
[Fig. 41]. Tighten front and backside of the arc chute
connections (4), including flat washers; use 5 Nm
[44 in-lbs]. Put on isolation caps (6).
S47183e rev.03 2009-09-02