10
4 - InstaLLatIon
4.1 - Installation of the front fastening supports, the
rear suspension rail and the rectangular duct outlets
4.1.1 - General
The front fastening supports and the rear suspension rail
are designed for the installation of the 4GM unit.
This allows these units to be installed while building proceeds
so that air ducts and the false ceiling can be installed much
sooner than is usual. The operative section of the 4GM
need not be installed until just before the tenants arrive.
They can be ordered for delivery very late in the building
cycle - a very important financial consideration where major
installations are involved.
Ducts connect the supports to the diffusers. These are rec-
tangular over a length that should be as short as possible in
order to minimise pressure losses (pressure losses in rec-
tangular ducts are higher than pressure losses in circular
ducts). They must then be changed to circular ducts with a
00 mm diameter, using an adaptor piece. The circular ducts
are then connected to the diffusers.
The pressure drops through the ducts must be compatible
with the performance of the 4GM. The internal duct sur-
faces must be as smooth as possible. Avoid sharp bends.
Check that there are no leaks and that they have not become
fouled during installation.
Protect the ducts against the ingress of building debris
which could be sucked into the unit possibly damaging the
fan, electric heater and the thermostatic damper on the
diffuser.
As required by local sound emission codes install sound
absorbing and damping materials.
4.1.2 - Installation of the front fastening support and the
rear suspension rail
The front suspension supports are supplied as pre-assembled
sub-assemblies (5 off) and can be disconnected and re-
assembled as required (M8 screws).
Once their installation site has been selected, use a complete
assembly as a template to mark the positions of the fasten-
ing points.
The supports must be fixed in a very rigid way to the con-
crete slab, suitable for the weight carried. They are designed
for the installation of the 4GM units (the fixing devices to
the concrete slab are not supplied by Carrier).
IMPORTANT: When positioning the front fastening sup-
ports take care to avoid damaging or changing the joint
plates on either side of the supports (these joints ensure
leak-tightness of the system. After the front fastening
supports have been installed, fix the rear suspension rail
parallel to the front supports, following the centre point
distances below. The rail must be fixed in a very rigid way
to the concrete slab, suitable for the weight carried (the
fixing devices to the concrete slab are not supplied by
Carrier).
VERY IMPORTANT: For correct operation of the 42GM
unit the front fastening supports and the rear suspension
rail must be level.
938
25
32
85
85
180
240
40
404
300
225
315
Ø124
150
38
260
225
30
56
886
991
1081
oblong 13x20
820
88
19
315
ø 124
All dimensions are given in mm.
Oblong 13 x 20
