Document number: SG104148TEN
Revision: B01
Issue date: 20.8.2012
Copyright© 2012 Sécheron SA - This document is not contractual and contains information corresponding to the level of technology at the date of release.
File: d-UR46-8S_maint_en.fm
D-33
UR46-81/82S
Maintenance
D.6
Detailed inspection
First perform a visual inspection, see §
D.5
.
D.6.1
Cleaning the contact area
a) Remove the spark arresters (2).
b) If the blowing device (7) is present, remove the electrode (5) without disconnecting its cable
and the electrode support (6). Clean them using a dry cloth. If the electrode (5) or the elec-
trode support (6) have burns, change them.
c) Using a dry cloth and a dust collector, clean the upper plate (3), the frame at the bottom (4) of
the cut-out chamber and the arc chute inlet (1).
d) Refit all components.
04623-S
D.6.2
Measuring the “W” contact wear dimension
Two different methods can be used. Use the method 1 when the lateral access to the main
contacts is possible.
The circuit-breaker must be closed.
Method 1
a) Remove a spark arrester (1).
b) Using a flexible graduated ruler (2), measure the W
1
distance between the base of the fixed
contact plate (3) and the horn (4) of the moving contact (5).
If W
1
≤
22
±
0.5
mm, replace the main contacts (see §
D.7
).
Note!
If the blowing device is present, read the ruler by looking between (6) the magnetic cheek (7) and
the main frame (8). If reading is not possible, remove both screws (9) and one magnetic cheek
(7).
04625-S
Note!
“W
1
” dimension for new contacts is 29±1mm.
1
5
6
4
4
3
7
2
5
10
15
20
25
30
35
40
45
50
55
60
65
70
5
10
15
20
25
30
35
40
45
50
55
60
65
70
1
3
9 8 7
6
2
4
A
5
W
1
3
22
4
B
5
W
1
Summary of Contents for UR46-81S
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