Installation
9229 0025 176 0A
45
2019-08-05
Earthing
Connecting to earth
Connect the vacuum circuit-breaker on the earthing terminal (70) to the high-voltage
protective earth as specified (DIN EN 50341).
Note
If the SION
®
vacuum circuit-breaker is installed into an earthed metal framework
and is connected permanently and electrically conductive, no separate earthing
is required.
Place serrated washers under the screw heads when fixing the vacuum circuit-
breaker in this case.
Fig. 67
Connecting the earthing conductor
Fig. 68
Connecting the earthing conductor
105 Nm
105 Nm
• Select the cross-section of the earthing conductor so
that a current of 30 A, with a maximum voltage drop
of 3 V can be conducted to the provided earthing
point (see IEC 62271-200).
• Remove hexagonal bolt M12 with washers from the
supplementary equipment, or if mounted, completely
unscrew from the earthing terminal.
• Observe the order of the fixing elements: Place the
washer, ring-main cable of earthing conductor and
contact washer (SN 70093) with the teeth facing the
operating mechanism box under the bolt head. Fix
M12 hexagonal bolt with the fixing elements to the
earthing terminal (70) with 105 Nm.
Fig. 69
Connect earthing conductor (example for
31.5 kA and distance between pole centres
150/160 mm)
105 Nm
