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INSTALLATION
Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National
Electrical Code) ANSI/NFPA 70 for special installa-
tion requirements.
2. Determine unit location (from project plans) or select
unit location.
3. Check for possible overhead obstructions which may
interfere with unit lifting or rigging.
Step 1 — Plan for Unit Location
Select a location for the unit and its support system (curb or
other) that provides for the minimum clearances required for
safety. This includes the clearance to combustible surfaces,
unit performance and service access below, around and
above unit as specified in unit drawings. See Fig. 5.
NOTE: Consider also the effect of adjacent units.
Be sure that the unit is installed such that snow will not
block the combustion air intake or flute outlet.
Unit may be installed directly on wood flooring or on Class
A, B, or C roof- - covering material when roof curb is used.
Do not install unit in an indoor location. Do not locate air
inlets near exhaust vents or other sources of contaminated
air. For proper unit operation, adequate combustion and
ventilation air must be provided in accordance with Section
5.3 (Air for Combustion and Ventilation) of the National
Fuel Gas Code, ANSI Z223.1 (American National Standards
Institute) and NFPA (National Fire Protection Association)
54 TIA- - - - 54- - - - 84- - - - 1. In Canada, installation must be in
accordance with the CAN1- - - - B149 installation codes for gas
burning appliances.
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto the
unit.
Locate mechanical draft system flue assembly at least 4 ft
(1.2 m) from any opening through which combustion
products could enter the building, and at least 4 ft (1.2 m)
from any adjacent building (or per local code). Locate the
flue assembly at least 10 ft (3.05 m) from an adjacent
unit's fresh air intake hood if within 3 ft (0.91 m) of same
elevation (or per local code). When unit is located
adjacent to public walkways, flue assembly must be at
least 7 ft (2.1 m) above grade.
Select a unit mounting system that provides adequate
height to allow installation of condensate trap per
requirements. Refer to Step 11 — Install External
Condensate Trap and Line for required trap dimensions.
Roof Mount —
Check
building
codes
requirements. Unit operating weight is shown in Table 1.
for
weight
distribution
Step 2 — Plan for Sequence of Unit Installation
The support method used for this unit will dictate different
sequences for the steps of unit installation. For example, on
curb- - mounted units, some accessories must be installed on
the unit before the unit is placed on the curb. Review the
following for recommended sequences for installation steps.
Curb- - mounted installation —
Install curb
Install field- - fabricated ductwork inside curb
Install thru- - base service connection fittings (affects
curb and unit)
Rig and place unit
Remove top skid
Install outside air hood
Install smoke detector tube
Install combustion air hood
Install flue hood
Install gas piping
Install condensate line trap and piping
Make electrical connections
Install other accessories
Pad- - mounted installation —
Prepare pad and unit supports
Rig and place unit
Remove duct covers and top skid
Install smoke detector return air sensor tube
Install field- - fabricated ductwork at unit duct openings
Install outside air hood
Install combustion air hood
Install flue hood
Install gas piping
Install condensate line trap and piping
Make electrical connections
Install other accessories
Frame- - mounted installation —
Frame- - mounted applications generally follow the
sequence for a curb installation. Adapt as required to
suit specific installation plan.
Step 3 — Inspect unit
Inspect unit for transportation damage. File any claim
with transportation agency.
Confirm before installation of unit that voltage, amperage
and circuit protection requirements listed on unit data
plate agree with power supply provided.
On units with hinged panel option, check to be sure all
latches are tight and in closed position.
Locate the carton containing the outside air hood parts; see
Fig. 7 and 13. Do not remove carton until unit has been
rigged and located in final position.
15
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