Installation
54
9229 0025 176 0E
2021-11-15
Screw-in depths for screws or threaded rods from the contact surface in the
upper and lower connection
*
only with additional active cooling (fc)
**
SION generator circuit-breaker
Fig. 81
Screw-in depths
Mounting conductor bars
For vacuum circuit-breakers with conductor bars, we recommend using the stainless
steel screws or non-magnetisable stainless steel screws included with the supple-
mentary equipment.
Adjust the conductor bars in such a way that, before fastening, they lie flat easily and
fit the holes on the contact surfaces of the upper and lower terminal.
Depending on the rated current strength, use M12 or M16 screws and nuts –
strength class 8.8 – and the appropriate spring elements and washers for the con-
nection of the conductor bars.
When tightening the screws, hold the nuts against the tightening torque with a suit-
able screwdriver or socket spanner.
Tightening torques apply to greased threads only:
- M12: 40 ±4 Nm
- M16: 100 ±10 Nm
Securing with a spiral
spring pin
The conductor bars can be secured against twisting with a spiral spring pin accord-
ing to ISO 8748 or a dowel pin according to ISO 8752 — 4 × X*
)
mm — N — C.
Rated voltage
U
r
kV
7.2 – 17.5
24
Rated short-circuit breaking current
I
sc
kA
16 – 31.5
31.5** / 40
16 – 25
16 – 25
Rated normal current
I
r
A
800 –
1600
2000 –
2500
1250
2000 –
3150 /
4000 fc*
800 –
1250
2000 –
2500
Connection thread
M12
M16
M12
M16
M12
M16
Upper terminal (A)
mm
20 ±1
20 ±1
28 ±1
Lower terminal (B)
mm
20 ±1
28 ±1
38 ±1
28 ±1
44 ±1
Fig. 82
Screw-in depths in the upper and lower termi-
nals
Fig. 83
Mounting the conductor bars (flat). Example
for 1 250 A with drill hole for dowel pin
M12: 40 ±4 Nm
M16: 100 ±10 Nm
