18-GD06D1-5
3
Installer’s Guide
f. It is always recommended that an auxiliary drain
pan be installed under a horizontal air handler (See
Condensate Drain Piping) to prevent possible dam-
age to ceilings.
g. Isolate the auxiliary drain pan from the unit or
from the structure.
h. Connect the auxiliary drain line to a separate drain
line (no trap is needed in this line) and terminate
according to local codes.
i. If a return duct is connected to the Air Handler, it
must be the same dimensions as the return open-
ing shown in the outline drawings.
C. DUCT CONNECTIONS
The supply and return air ducts should be connected to
the unit with flame retardant duct connectors.
Convertible duct flanges are provided to make a “flush fit”
for ¾” or 1-1/2” ductboard applications. Three are located
in the accessory kit shipped with the unit and one is in-
stalled on the discharge opening. If the duct flanges are
not needed, the installed flange must be removed. See the
Outline drawing for sizes of the discharge opening. After
ductwork is secured, seal the ductwork per local and na-
tional codes to prevent air loss/infiltration.
D. REFRIGERANT PIPING
IMPORTANT:
Refrigerant piping must be routed to maintain service access
to blower compartment and provide easy removal of filter ac-
cess panel and filter.
1. Refrigerant connections are made outside the cabinet.
NOTE:
TXV bulb
MUST
be protected (wrap a wet rag around
the suction line between the TXV bulb and the braze
joint) or removed, while brazing the tubing. Overheat-
ing of the sensing bulb will affect the functional char-
acteristics and performance of the air handler.
2. If changing the Thermostatic valve (TEV/TXV), be sure
to use a wrench and backup wrench to
tighten the
mechanical fittings 1/6 turn past finger tight
upon
installation.
3. Installation of refrigerant lines is covered in the instal-
lation instructions packaged with the outdoor unit.
Evacuation, leak testing and brazing procedures are
included in those instructions. Read those instructions
before starting installation of refrigerant lines.
NOTE:
TXV Equipped is Non-Bleed, and may require a start
kit on the outdoor unit.
NOTE:
Refrigerant line openings must be sealed along with
field wiring.
E. BRAZING TO EVAPORATOR SECTION
IMPORTANT:
Do noT unseal refrigerant tubing until ready to cut and fit
refrigerant lines.
1. Remove the sealing caps from indoor coil field connec-
tions.
2. Field supplied tubing should be cut squared-off, ensur-
ing the tube is still round and free of burrs at the con-
necting end. Clean the tubing to prevent contaminants
from entering the system.
3. Run refrigerant tubing into the stub sockets of indoor
unit coil.
Refrigerant line openings must be com-
pletely sealed.
4. Braze and evacuate according to indoor and outdoor in-
stallation instructions.
IMPORTANT:
Painted areas of unit must be shielded during brazing.
F. CONDENSATE DRAIN PIPING
NOTE:
Make certain that the unit has been installed in a level
position to ensure proper draining.
The indoor blower is downstream of the evaporator coil
which creates a negative pressure at the condensate
drain connections during operation. The condensate
drain connections in front of the indoor coil are 3/4"
NPT. The lower connection is the primary drain. See
Figure 3.
Two secondary drain connections are provided for the
different orientations (See Figure 3). The lower of the
two should be connected as a backup to prevent con-
densate overflow by a blocked primary drain. The weep
hole in center of drain coupling area should be sealed
with caulk or RTV.
For proper drainage of condensate, the following steps
should be followed:
1. The primary drain line must be trapped with a min-
imum of 2" water seal as shown in Figures 4 & 5
.
2.
Do not use preformed 3/4" PVC running traps.
The use of Field fabricated or manufactured traps
as shown in Figures 4 & 5 is acceptable. The man-
ufactured trap shown in Figure 4 allows for a float
switch option to be added. Refer to the manufac-
turers data and instructions for details.
3.
The trap must be located within 4 feet of the
air handler drain outlet connection.
4. It
is recommended that a clean-out tee or cross be
installed in the primary drain line for future main-
tenance (See Figures 4 & 5).
Figure 3
3/4" NPT
Primary
drain
connection
3/4" NPT
Secondary
drain
connection
Seal weep
hole
