2
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can
be hazardous due to system pressure and electrical compo-
nents. Only trained and qualified service personnel should in-
stall, repair, or service air-conditioning equipment.
Untrained personnel can perform basic maintenance func-
tions of cleaning coils and filters and replacing filters. All other
operations should be performed by trained service personnel.
When working on air-conditioning equipment, observe precau-
tions in the literature, tags and labels attached to the unit, and
other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for unbrazing operations. Have
fire extinguisher available for all brazing operations.
INSTALLATION
Unit is shipped in the vertical configuration. To convert to
horizontal configuration, remove side duct opening covers. Us-
ing the same screws, install covers on vertical duct openings
with the insulation-side down. Seals around duct openings
must be tight.
Step 1 — Provide Unit Support
ROOF CURB — Assemble and install accessory roof curb in
accordance with instructions shipped with curb. See Fig. 1 and
2. Install insulation, cant strips, roofing felt, and counter flash-
ing as shown. Ductwork must be attached to curb. If electric or
control power is to be routed through the basepan, attach the
accessory thru-the-bottom service connections to the basepan
in accordance with the accessory installation instructions. Con-
nections must be installed before unit is set on roof curb.
Curb should be level. Unit leveling tolerances are shown in
Fig. 1. This is necessary for unit drain to function properly. Re-
fer to Accessory Roof Curb Installation Instructions for addi-
tional information as required.
SLAB MOUNT (Horizontal Units Only) — Provide a level
concrete slab that extends a minimum of 152 mm (6 in.) be-
yond unit cabinet. The slab should be 203 mm (8 in.) thick with
102 mm (4 in.) above grade. Install a gravel apron in front of
condenser coil air inlet to prevent grass and foliage from ob-
structing airflow.
NOTE: Horizontal units may be installed on a roof curb if
required.
Step 2 — Field Fabricate Ductwork —
On verti-
cal discharge units, secure all ducts to roof curb and building
structure. Do not connect ductwork to unit. For horizontal ap-
plications, field-supplied flanges should be attached to horizon-
tal discharge openings and all ductwork attached to the flanges.
Insulate and weatherproof all external ductwork, joints, and
roof openings with counter flashing and mastic in accordance
with applicable codes.
Ducts passing through an unconditioned space must be in-
sulated and covered with a vapor barrier.
If a plenum return is used on a vertical unit, the return
should be ducted through the roof deck to comply with applica-
ble fire codes.
A minimum clearance to combustibles is not required
around ductwork on vertical discharge units. On horizontal
discharge units with electric heat, a minimum clearance of
25 mm (1 in.) is required for the first 305 mm (12 in.) of duct-
work. Cabinet return-air static should not exceed –87 Pa
(–0.35 in. wg) with Durablade economizer, or –12 Pa
(–0.45 in. wg) without economizer.
Before performing service or maintenance operations on
unit, turn off main power switch to unit and install lockout
tag. Electrical shock could cause personal injury.
Ensure voltage listed on unit data plate agrees with electri-
cal supply provided for the unit.
IMPORTANT: The gasketing of the unit to the roof curb
is critical for watertightness. Install gasket supplied with
the roof curb as shown in Fig. 2. Improperly applied
gasket can also result in air leaks and poor unit
performance.
MAXIMUM ALLOWABLE DIFFERENCE (in.)
A-B
B-C
A-C
mm
in.
mm
in.
mm
in.
13
.5
25
1.0
25
1.0
Fig. 1 — Unit Leveling Tolerances
Содержание WEATHERMAKER 50TFQ008
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