Step 5 - Field Fabricate Ductwork; Step 6 - Rig And Place Unit - Carrier WeatherMaster 50HC14 Installation Instructions Manual

A
B
MAXIMUM ALLOWABLE DIFFERENCE IN. (MM)
A-B
0.5" (13) 1.0" (25)
Fig. 5 — Unit Leveling Tolerances
Install insulation, cant strips, roofing felt, and counter flash-
ing as shown. Ductwork must be attached to curb and not to
the unit.
IMPORTANT: If the unit's electric and control wiring is to
be routed through the basepan and the unit is equipped with
the factory-installed Thru-the-Base service option see the
following sections:
• Factory-Option Thru-Base Connections on page 19
If using the field-installed Thru-the-Base accessory follow
the instructions provided with the accessory kit.
NOTE: If electrical connection is not going to occur at this
time, tape or otherwise cover the fittings so that moisture does
not get into the building or conduit in the interim.
SLAB MOUNT (HORIZONTAL UNITS ONLY) — Pro-
vide a level concrete slab that extends a minimum of 6 in. (150
mm) beyond unit cabinet. Install a gravel apron in front of con-
denser coil air inlet to prevent grass and foliage from obstruct-
ing airflow.
NOTE: Horizontal units may be installed on a roof curb if
required.
ALTERNATE UNIT SUPPORT (IN LIEU OF CURB OR
SLAB MOUNT) — A non-combustible sleeper rail can be
used in the unit curb support area. If sleeper rails cannot be
used, support the long sides of the unit with a minimum of 3
equally spaced 4-in. x 4-in. (102 mm x 102 mm) pads on each
side.
Step 5 — Field Fabricate Ductwork
NOTE: Cabinet return-air static pressure (a negative condition)
shall not exceed 0.35 in. wg (87 Pa) with economizer or 0.45
in. wg (112 Pa) without economizer.
For vertical ducted applications, secure all ducts to roof curb
and building structure. Do not connect ductwork to unit.
Fabricate supply ductwork so that the cross sectional di-
mensions are equal to or greater than the unit supply duct open-
ing dimensions for the first 18 in. (458 mm) of duct length
from the unit basepan.
B-C A-C
1.0" (25)
Insulate and weatherproof all external ductwork, joints, and
roof openings with counter flashing and mastic in accordance
with applicable codes.
Ducts passing through unconditioned spaces must be insu-
lated 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.
C
FOR UNITS WITH ACCESSORY OR OPTIONAL ELEC-
TRIC HEATERS — All installations require a minimum
clearance to combustible surfaces of 1-in. (25 mm) from duct
for first 12-in. (305 mm) away from unit.
Outlet grilles must not lie directly below unit discharge.
NOTE: A 90-degree elbow must be provided in the ductwork
to comply with UL (Underwriters Laboratories) code for use
with electric heat.
PERSONAL INJURY HAZARD
Failure to follow this warning could cause personal injury.
For vertical supply and return units, tools or parts could
drop into ductwork and cause an injury. Install a 90-degree
turn in the return ductwork between the unit and the condi-
tioned space. If a 90-degree elbow cannot be installed, then
a grille of sufficient strength and density should be installed
to prevent objects from falling into the conditioned space.
Due to electric heater, supply duct will require 90-degree
elbow.
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in damage to roof-
ing materials.
Membrane roofs can be cut by sharp sheet metal edges. Be
careful when placing any sheet metal parts on such roof.
Step 6 — Rig and Place Unit —
ready to be rigged and no longer will be lifted by a fork truck,
the wood protector under the basepan must be removed. Re-
move 4 screws from each base rail. Wood protector will drop to
the ground. See instructions on the unit base rails.
Keep unit upright and do not drop. Spreader bars are re-
quired. Rollers may be used to move unit across a roof. Level
by using unit frame as a reference. See Table 1 and Fig. 6 for
additional information.
Lifting holes are provided in base rails as shown in Fig. 6.
Refer to rigging instructions on unit.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment dam-
age.
All panels must be in place when rigging. Unit is not
designed for handling by fork truck when panels or pack-
aging are removed.
Before setting the unit onto the curb, recheck gasketing on
curb.
9
WARNING
CAUTION
When the unit is
CAUTION