Carrier 50NQ - Manual (Page 4)

RATING CONTROL BOX BLOWER
PLATE ACCESS DOOR ACCESS
DOOR
Fig. 4—Rating Plate Location
Step 1—Moving and Setting Unit in Piace
A CAUTION
Use spreader bars and crate top when rigging the unit
to be lifted. Model 50NQ must be rigged for lifting as
shown in Fig. 5. Use extreme caution to prevent dam­
age when moving the unit. Unit must remain in an
upright position during all rigging and moving opera­
tions. The unit must be level for proper condensate
drainage; therefore, the ground-level pad or accessory
roof-mounting curb must be level before setting the
unit in place. When a field-fabricated support is used,
ensure that the support is level and properly supports
the unit.
ROOFTOP INSTALLATION
A CAUTION
When installing the unit on a rooftop, be sure that the
roof will support the additional weight. Refer to Figs. 2
and 3 for total weight and corner weight information.
For downflow applications, an accessory roof-mounting
curb may be installed on, and flashed into the roof before
unit installation. The instructions for installing the acces­
sory curb are packaged with the curb.
For end-discharge applications place the unit on a level base
that provides proper support. Refer to Fig. 7 for location of
additional supports/sleepers. On flat roofs, be sure that the
unit is located at least 4 ins. above the highest expected
water level on the roof to prevent flooding.
GROUND-LEVEL INSTALLATION
Place the unit on a solid, level, concrete pad that extends
approximately 2 ins. beyond the casing on all four sides of
the unit. Do not secure the unit to the pad except when
required by local codes. Ensure pad does not obstruct coil
drainage holes in bottom of unit. (Holes drain water during
cooling and defrost cycles.) In areas where prolonged sub­
freezing temperatures or snowfall occur, increase clearance
to 12-18 ins. by constructing an angle-iron frame to support
Fig. 5—Suggested Rigging
the unit. The frame should be designed so as not to block
the drainage holes. See Fig. 8 and Table 1 for recommended
frame construction. Extend a 24-in. gravel apron around
pad for condensate and defrost water drainage.
CLEARANCES
The required minimum operating and service clearances are
shown in Figs. 2 and 3. Adequate condenser air must be
provided.
A CAUTION
Do not restrict condenser airflow. An air restriction at
either the outdoor-air inlet (the entire surface of the out­
door coil) or the fan discharge can be detrimental to
compressor life.
The condenser fan discharges through the top of the unit.
Ensure that the fan discharge does not recirculate to the
condenser coil. Do not locate the unit in either a corner or
under a complete overhead obstruction. The minimum clear­
ance under a partial overhang (such as a normal house roof
overhang) is 48 ins. above unit top. The maximum horizon­
tal extension of a partial overhang must not exceed 48 ins.
Do not locate the unit where water, ice, or snow from an
overhang or roof will damage or flood the unit by falling on
the top. Do not locate the unit where grass, shrubs, or other
plants will interfere with the airflow either into or out of the
unit. Do not install the unit on carpeting, tile, or other com­
bustible material other than wood flooring. Heat pump may
be installed on wood flooring or on Class A, B, or C roof cov­
ering materieds.
Step 2—Condensate Disposal
NOTE: Ensure that condensate-water disposal methods
comply with I oce J codes, restrictions, and practices.
Model 50NQ disposes of condensate water through a 3/4-in.
NPT drain fitting. See Figs. 2 and 3 for location.
Install a 3-in. trap at the dredn fitting to ensure proper
drainage. See Fig. 6. Meike sure that the outlet of the trap is
at least 1 in. lower than the unit drain pan connection to
prevent the pan from overflowing. Prime the trap with
water.
If the installation requires draining the condensate water
away from the unit, connect a drain tube using a minimum
of 7/8-in. OD copper tubing, 3/4-in. gedvemized pipe, or
3/4-in. plastic pipe. Do not undersize the tube. Pitch the