ABB UniSec DY800, Инструкции по установке, обслуживанию и техническому обслуживанию

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UNISEC DY800 - E D. 4 - ACCORDING TO E- DISTRIBUZIONE SPECIFIC ATIONS
- INS TA LL ATI ON M A NUA L
8.7 Connections
Earthing
busbar junction
Connecting bar
28 Nm tightening
torque
GENERAL WARNINGS
Make sure that the fixed couplings of the
switchgear and the connections (cable terminals,
busbar connections) are clean and free from any
deformation caused by shocks received during
transport or storage.
Eliminate all traces of oxidation with a fine file or
emery cloth.
8.7.1 Power circuit
Main busbars for UniSec DY800 units coupled to
mixed cubicles. Make sure that the contact zone of
the busbars and bearing insulators is perfectly clean
and degreased. Assemble the busbars (C) as
indicated in the drawing, by placing them on the
contact area of the apparatus. Position the strip (A)
on the upper surface of the busbar (C). The holes in
the two components must match. Tighten all the
screws (B) by hand. Remember to use the relative
washers and to also include the strip (A), as shown
in the drawing. After this, tighten the screws with a
torque wrench. Apply max. 60 Nm tightening torque.
Repeat the operation for all three phases.
Main busbars for UniSec DY800/316 units coupled
to open-type cubicles
Make sure that the contact area of the busbars and
supporting insulators is perfectly clean and
degreased. Repeat the operations described in the
previous paragraph for the central phase (detail D).
Make sure that the strip (A) is also connected.
Only couple the busbars for the remaining phases,
since the strips are already connected (comply with
the previously described procedure).
Tightening torque
60 Nm max
8.7.2 Earthing busbars
The earthing busbar is routed longitudinally along
the lower part of the switchgear. There are copper
alloy bolts at its end for connecting to the earthing
network of the installation.
The screws and bolts must be tightened to the
prescribed tightening torque value (28 Nm) so as to
prevent vibrations during operation from working
them loose.
The earth conductor must be sized to withstand the
forecast maximum earth fault current. Generally
speaking, the section of the earth conductor must
not be less than that of the earthing busbar of the
switchgear. All cubicles are normally equipped with
an earthing busbar whose section guarantees > 200
A/mm
2 current density.
The earthing busbar junction must be made on a
level with the points in which the switchgear
cubicles join together. Remove any traces of
oxidation from the contact surface of the busbars
beforehand, using emery cloth.
Lock the earthing busbar junction in place with its
screws, flat and spring washers and with the nut
and its respective washer.
Fix the busbars as shown in the figure.
—
8. Installation
B
C A