
24
2
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
block off the busbars using insulating screens.
BX800 to 1600 (fixed devices)
F
146.5
A
(*)
A
(*)
B
B
(*) An overhead clearance of 50 mm
is required to remove the arc chutes.
Insulated parts
Metal parts
Live parts
A
0
120
180
B
0
10
60
F Datum
Installation example
Direct connection by bare
cables, devices with terminal
shields.
Connection by cables with lugs,
devices with terminal shields.
Connection by insulated bars,
devices with terminal shields.
Rear connection or plug-in
base, devices with terminal
shields.
Minimum dimensions (mm)
A
BX800 to 1600
250
Painted sheetmetal
Operating characteristics and performance
2-2 Breaking performance