19
The busbar connections are made through the top openings
a) Clean and scrape the busbar connections.
b) Clean the insulation of the busbar sections with a soft, dry
cloth and check for any insulation damage.
c) Install the busbars unit by unit. Insert the screws, busbars
and other required components in the correct positions
and tighten them to the correct torques according to the
instructions given below.
Instructions for different types of main busbar connections
The main busbars overlap each other at their contact points.
This means that every other busbar is mounted on top of the
other, as shown in Figure 51. Busbar spacers are used in
the end units to keep the busbars in a completely horizontal
position.
Figure 51. Main busbar connections
4.5.6 Connecting the main busbars
General warnings and precautions
DANGER
A warning sign is placed on the top plate to
indicate the presence of high voltage under
the roof.
CAUTION
It is recommended to mount the busbars
starting from the top of the units.
NOTE
Tighten to the correct torque. The torques
are indicated in the “Tightening torques for
steel screws and nuts/bolts” table.
NOTE
It is important for the screws to be of the
correct length.
Busbar spacer
Busbar Busbar spacer
1
Odd
numbered
unit
2
Even
numbered
unit
3
Odd
numbered
unit
4
Even
numbered
unit
5
Odd
numbered
unit
4.5.5 Fixing the switchgear to the floor
(See Figures 35, 36 and 37).
Fixing to the metal frame
a) The switchgear must be fixed to the metal frame by welding
through the holes in the bottom of the unit (2 welding seams/
unit) or with two bolts/unit straight into the concrete floor.
b) Fix as shown in Figure 50.
Figure 50. Fixing the switchgear to the floor
Fixing to a concrete floor with anchoring bolts
a) Level the floor both longitudinally and transversely.
b) Drill the fl oor at the fi xing points, referring to the slab drilling dia-
grams. Use a hammer drill with a suitable bit to make the holes.
c) After installing the unit, insert the expansion anchoring bolts
into the holes.
d) Fix as shown in Figure 50.
Fixing to a floating floor
a) Drill the floor at the fixing points, referring to the slab drilling
diagrams. Use a drill with a suitable bit for the type of fixing
to be carried out to make the holes (smooth or threaded
through hole).
b) Fix as shown in Figure 50.
Summary of Contents for UniSec
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