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B-4
Installation in switchboards
Safety clearances
and minimum distances
General rules
When installing a circuit breaker, minimum distances (safety clearances) must be
maintained between the device and panels, bars and other protection devices
installed nearby. These distances, which depend on the ultimate breaking capacity,
are defined by tests carried out in accordance with standard IEC 60947-2.
If installation conformity is not checked by type tests, it is also necessary to:
use insulated bars for circuit-breaker connections
b
block off the busbars using insulating screens.
b
Installation
recommendations
Compact NS630b to 3200 (fixed devices)
Insulated parts
Metal parts
Live parts
NS630b to 1600
A
0
120
180
B
0
10
60
NS1600b to 3200
A
50
170
230
B
0
10
60
Compact NS630b to 1600 (withdrawable devices)
Insulated parts
Metal parts
Live parts
A
0
0
30
B
10
10
60
C
0
0
30
F
Datum
DB128166
F
146.5
A
(*)
DB128167
A
(*)
B
B
(*)
An overhead clearance of 50 mm is required to
remove the arc chutes.
DB128168
F
40
180
A
DB128169
B
B
C
C