9
ceiling joists by additional layers of vibration absorbing mesh.
In both cases, a
3
/
4
-in. drain connected to this secondary pan
should be run to an eave at a location that will be noticeable.
VERTICAL AND DOWNFLOW UNITS (50PCV, PCD) —
Vertical and counterflow units should be mounted level on a
vibration absorbing pad slightly larger than the unit base in
order to minimize vibration transmission from the unit to the
building structure. See Fig. 8. It is generally not necessary to
anchor the unit unless required by local code.
All major service access for the vertical and counterflow
models is from the front side of the unit. When installing the
unit in a confined space such as a closet, ensure that the service
panel screws are accesible, that the filter can be replaced with-
out damage and that water and electrical connections are ac-
cesible. For models with a unit-mounted disconnect switch,
make sure the switch can be easily seen and operated.
To reduce sound transmission, units should be installed us-
ing flexible electrical conduit and hose kits. Care should be tak-
en to ensure that no part of the unit cabinet is touching part of
the building structure. For ducted return applications, a flexible
duct connection should be used. Mount the unit on a vibration
absorption pad slightly larger than the entire base to minimize
vibration transmission. It is not necessary to mount the unit on
the floor.
Step 5 — Check Duct System —
All units are pro-
vided with a return air duct flange and supply air duct connec-
tions. Refer to unit dimensional drawings (Fig. 1-3) for
physical dimensions of the collar and flange.
A flexible connector is recommended for supply and return
air duct connections on metal duct systems. All metal ducting
should be insulated with a minimum of 1 in. duct insulation to
avoid heat loss or gain and prevent condensate from forming
during the cooling operation. Application of the unit to uninsu-
lated ductwork is not recommended as the unit’s performance
will be adversely affected.
If the unit will be installed in a new installation with new
ductwork, the installation should be designed using current
ASHRAE (American Society of Heating, Refrigerating, and
Air-Conditioning Engineers) procedures for duct sizing. If the
unit will be connected to an existing duct system, a check
should be made to assure that the duct system has the capacity
to handle the air required for the unit application. If the duct
system is too small, larger ductwork must be installed. Be cer-
tain to check for existing leaks and repair. The duct system and
all diffusers should be sized to handle the designed airflow qui-
etly. To maximize sound attenuation of the unit blower, the
supply and return air plenums should be insulated. There
should be no direct straight air path throught the air grille into
the heat pump. The return air inlet to the heat pump must have
at least one 90-degree turn away from the space return air
grille. If air noise or excessive airflow are a problem, the blow-
er speed can be changed to a lower speed to reduce airflow.
(Refer to motor speeds and settings in Tables 3 and 4.)
HORIZONTAL SUPPLY AIR CONFIGURATION CON-
VERSION — The supply air location on horizontal units can
be quickly field converted from end blow to straight through or
vice-versa. To convert the supply air direction, follow the steps
below:
1. If connected to power, shut off the unit and disconnect
switch or circuit breaker.
2. Unscrew and remove the blower access panel.
3. Disconnect the wires from the unit electrical box to the
blower motor. Note which speed taps are wired for units
with PSC or constant torque motors.
4. Unscrew and carefully remove the blower panel with the
blower and motor attached. Be careful not to damage the
refrigerant coils or any other internal unit components.
5. Remove the blower support brackets from the bottom of
the blower housing and relocate them to the top of the
blower housing.
6. Turn the blower panel 180 degrees so that the blower sup-
port brackets are now at the bottom of the blower.
7. Insert the blower panel with the blower and motor into
the desired location. Be careful not to damage the refrig-
erant coils or any other internal unit components. Screw
the panel into place.
8. Replace the wires between the blower motor and electri-
cal box. Make sure to connect wires to the proper speed
taps.
9. Replace the blower access panel.
10. Reconnect power to the unit.
Step 6 — Install Condensate Drain —
A drain
line must be connected to the heat pump and pitched away
from the unit a minimum of
1
/
8
-in. per foot to allow the con-
densate to flow away from the unit.
This connection must be in conformance with local plumb-
ing codes. A trap must be installed in the condensate line to en-
sure free condensate flow. (Heat pumps are not internally
trapped). A vertical air vent is sometimes required to avoid air
pockets. See Fig. 9.
CAUTION
If the unit is located in a crawl space, the bottom of the unit
must be at least 4-in. above grade to prevent flooding of the
electrical parts due to heavy rains.
VIBRATION
MOUNTING
PAD
Fig. 8 — Mounting Vertical Units
CAUTION
Do not connect discharge ducts directly to the blower out-
let. The factory filter rack should be left in place on a free
return system.
