Table of Contents
Advertisement
28
U N I G E A R Z S 2 I N S TA L L AT I O N , O P E R AT I O N A N D M A I N TA I N A N C E I N S T R U C T I O N M A N U A L
Front clearance
Rear clearance
Lateral clearance
Ceiling height
In case of installation with arc pressure relief
ducts, it guarantees prevention of overpressure
and gases being deposited inside the installation
room in a rare event of internal arcing and with a
minimum (3000 mm) ceiling height.
The duct may exhaust to the outside laterally.
Care must be taken prevent access of people into
the gas exit area. The gas exhaust louvers must
prevent any water, dust, animals, or other foreign
bodies from entering.
5.8 Foundations
The following three basic methods of installing
switchgear in the switch room are identified:
Method A – installation on "C" profile base irons
As standard, it is recommended to install the
switchgear on "C" profile base irons set into the
concrete floor of the switchgear room. In this
case, the units are fastened using the
special bolt blocks (ABB delivers these on
request).
Method B – installation on the levelled
concrete floor
Installation directly on the levelled concrete floor
makes much higher demands on the floor
levelling, which must, in this case, fulfill the same
tolerances as the base irons during method A
installation.
Fastening is carried out by anchoring bolts in the
concrete floor.
Method C – installation on a raised false floor
In this case, fastening of the units is carried out
by welding outside panels to the steel floor frame
in the places where the frame is larger than the
base of the switchgear, i.e. on the outside lateral
walls of the unit row. This method of installation
is not recommended if seismic resistance is
required.
Generally, the following procedure for switchgear
anchoring can be recommended for any of the
installation methods mentioned:
1.
The switchgear panels are bolted together in
the front and rear part to make one unit;
2. Further structural data guidelines given
provide a rough calculation of the space
required and the plan for designing the room
for a switchgear project.
1500 mm min. (considering withdrawal of CB/VT Truck)
1500 mm min. (considering withdrawal of Line PT)
Less than 200 mm or more than 700 mm.
When the arc pressure relief ducts are not applied by the substation building
Designer, a general precedent is min. 3500 mm for 25kA level and min 4000mm for 31,5kA level.
The building designer may take more detailed drawings and advices from related ABB Office
during order correspondence.
If seismic resistance is not required, it is not
necessary to attach each switchgear panel to the
floor or frame, but it suffices to fix outside panels
in each row of switchgear only.
If seismic resistance is required, it is necessary to
attach each switchgear panel to the floor or
frame. To achieve seismic resistance the special
fixing system is used. This system preferably
uses a steel floor frame with "C" profile shape
but moreover with an addition special fixing
element – please contact ABB for details.
When the final building construction documents
are drawn up, the binding data supplied by ABB
for a particular case must always be taken into
account!
5.8.1 Method of installation A – installation of
the base irons
The general foundation drawing is given in
figures below according to the parameters
of the units.
•
The "C" shaped base irons can be supplied by
ABB together with the switchgear. Their
installation is usually carried out by personnel
on site and, if possible, should be performed
under supervision of an ABB specialist.
The base irons must be installed in the slab
before finishing the floor;
•
Rest the irons in the specified position on the
concrete floor as shown in the relevant
foundation drawing and mark out the places
for drilling the holes. Then drill the holes for
anchoring bolts, i.e. for plugs for fixing the
base irons in the floor. Then put the plugs in
the holes and attach the base irons to the
floor loosely with bolts, without final
tightening so that any required levelling is
possible.
•
Carefully level the base irons both
longitudinally and transversally over the entire
length and to the correct height by putting
strips of suitable thickness under them and
using a levelling instruments.
Tolerances for laying the floor frame are
Evenness tolerance: ± 1 mm over a measuring
length of 1 m Straightness tolerance: 1 mm per
1m, but not more than 3 mm over the entire
length of the frame.
Advertisement
Table of Contents
