Installation
18
RT-SVX39B-EN
Downflow Units
Roof Curb
The roof curbs for these units consists of a “full perimeter”
enclosure to support the unit just inside of the unit base
rail.
Before installing any roof curb, verify;
1.
That it is the correct curb for the unit,
2. That it includes the necessary gaskets and hardware,
3. That the purposed installation location provides the
required clearance for proper operation.
4. Insure that the curb is level and square. The top surface
of the curb must be true to assure an adequate curb-to-
unit seal.
5. Verify that appropriate materials were used in the
construction of roof and ductwork. Combustible
materials should not be used in the construction of
ductwork or roof curb that is in close proximity to
heater elements or any hot surface. Any combustible
material on the inside of the unit base should be
removed and replaced with appropriate material.
Step-by-step curb assembly and installation instructions
ship with each accessory roof curb kit. Follow the
instructions carefully to assure proper fit-up when the unit
is set into place.
Note:
To assure proper condensate flow during
operation, as well as proper operation of the
condensate overflow switch (if equipped), the unit
and curb must be level. Condensate Overflow
Switch will not work if unit is not level or slightly
sloped toward switch.
If the unit is elevated, a field constructed catwalk around
the unit is strongly recommended to provide easy access
for unit maintenance and service.
Recommendations for installing the Supply Air and Return
Air ductwork joining the roof curb are included in the curb
instruction booklet. Curb ductwork must be fabricated and
installed by the installing contractor before the unit is set
into place.
Note:
For sound consideration, cut only the holes in the
roof deck for the ductwork penetrations. Do not cut
out the entire roof deck within the curb perimeter.
If a Curb Accessory Kit is not used:
a. The ductwork can be attached directly to the
factory-provided flanges around the unit’s supply
and return air openings. Be sure to use flexible duct
connections at the unit.
b. For “built-up” curbs supplied by others, gaskets
must be installed around the curb perimeter flange
and the supply and return air opening flanges.
Rigging
A Rigging illustration and Center-of-Gravity dimensional
data table is shown in
. Refer to the typical
unit operating weights table before proceeding.
1.
Remove all drill screws fastening wood protection to
metal base rail. Remove all screws securing wooden
protection to wooden top crate.
2. Remove Wooden Top Crate.
Figure 13.
Heat pump - 5 ton - downflow airflow
supply/return - through the base utilities
Note:
All dimensions are in inches/millimeters.
Figure 14.
Heat pumps - 6-10 ton - downflow airflow
supply/return - through the base utilities
Note:
All dimensions are in inches/millimeters.
THROUGH
THE BASE
ELECTRICAL
SUPPLY
RETURN
TBU CONDENSATE
3 5/8”
9
2 MM
14”
356 MM
9
1/4”
235 MM
15 1/2”
3
9
4 MM
4”
102 MM
24”
610 MM
16”
406 MM
4 3/16”
106 MM
23 1/2”
5
9
7 MM
2 13/16”
71 MM
6 1/2”
165 MM
3 11/16”
9
4 MM
4 7/8”
124 MM
5 1/16”
128 MM
9
15/16”
253 MM
WARNING
Combustible Materials!
Maintain proper clearance between the unit heat
exchanger, vent surfaces and combustible materials.
Refer to unit nameplate and installation instructions for
proper clearances. Improper clearances could result in a
fire hazard. Failure to maintain proper clearances could
result in death or serious injury or property damage.
