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RT-SVX36G-EN
Installation
Trane Roof Curb and Ductwork
The roof curbs for 20 through 130 Ton units consists of two main components; a pedestal to support
the unit’s condenser section and a “full perimeter” enclosure to support the unit’s air handler
section.
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.
Step-by-step curb assembly and installation instructions ship with each Trane 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, the unit (and curb) must be as level as
possible. The maximum slope allowable for rooftop unit applications, excluding SSH_'s, is
4" end-to-end and 2" side-to-side. Units with steam coils (SSH_'s) must be set level!
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.
Pitch Pocket Location
The location of the main supply power entry for S_HL 20 through 89 Ton rooftop units is located
at the bottom right-hand corner of the control panel.
and
illustrate the location
for the electrical entrance through the base in order to enter the control panel. If the power supply
conduit penetrates the building’s roof beneath this opening, it is recommended that a pitch pocket
be installed before the unit is placed onto the roof curb. The center line dimensions shown in the
illustration below indicates the center line of the electrical access hole in the unit base when it is
positioned on the curb, ±3/8 inch. The actual diameter of the hole in the roof should be at least 1/
2 inch larger than the diameter of the conduit penetrating the roof. This will allow for the clearance
variable between the roof curb rail and the unit base rail illustrated in
.
The pitch pocket dimensions listed are recommended to enhance the application of roofing pitch
after the unit is set into place. The pitch pocket may need to be shifted as illustrated to prevent
interference with the curb pedestal.
