508133G01 / 31-5000715
Page 3 of 25
Issue 2140
Exhaust vents from dryers, water heaters and furnaces
should be directed away from the outdoor unit.
Prolonged exposure to exhaust gases and the chemicals
contained within them may cause condensation to form
on the steel cabinet and other metal components of the
outdoor unit. This will diminish unit performance and
longevity.
IMPORTANT
When outdoor unit is connected to factory-approved indoor
unit, outdoor unit contains system refrigerant charge for
operation with matching indoor unit when connected by 15
ft. of field-supplied tubing. For proper unit operation, check
refrigerant charge using charging information located on
control box cover.
Indoor Coil TXV Selection
The outdoor section must be matched to a factory approved
indoor section. It is mandatory that the installer ensure that
the correct TXV is installed in the indoor section. Reference
Refrigerant Piping - Typical Existing Fixed Orifice Removal
Procedure. If necessary, remove the existing piston and
replace it with the correct TXV. See Refrigerant Piping -
Typical Existing Expansion Valve Removal Procedure
for details of changing the piston or TXV. The NS18HMA
models are only rated with TXV on the indoor coil.
Outdoor Section
Zoning ordinances may govern the minimum distance the
condensing unit can be installed from the property line.
Discharge Air
Mounting Slab
Ground Level
Building
Structure
Mounting slab must slope slightly away from
building, not to exceed 1/4” per foot.
Figure 1. Slab Mounting
Install on a Solid, Level Mounting Pad
The outdoor section is to be installed on a solid foundation.
This foundation should extend a minimum of 2” (inches)
beyond the sides of the outdoor section. To reduce the
possibility of noise transmission, the foundation slab
should NOT be in contact with or be an integral part of the
building foundation. See Figure 1.
If conditions or local codes require the unit be attached to
pad or mounting frame, tie down bolts should be used and
secured to unit base pan.
Elevate Unit
Accumulation of water and ice in base pan may cause
equipment damage.
CAUTION
Elevate unit per local climate and code requirements to
provide clearance above estimated snowfall level and
ensure adequate drainage of unit. Use snow stand in areas
where prolonged freezing temperatures are encountered.
If conditions or local codes require the unit be attached to
pad or mounting frame, tie down bolts should be used and
fastened through knockouts provided in unit base pan.
Clearance Requirements
When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. For proper airflow,
quiet operation and maximum efficiency. Position so water,
snow, or ice from roof or eaves cannot fall directly on unit.
Refer to Table 1 for installation clearances.
Location
Minimum Clearance
Service box
30”
Top of unit*
48”
Between units
24”
Against wall
6”
* Maximum soffit overhang is 36”.
NOTE
: At least one side should be unobstructed by a wall or
other barrier.
Table 1. Clearances
30” around
Control
Box
24”
6”*
Figure 2.
Note: See Table 1 for specific minimum clearance guidelines.
