4
18-AD25D1-4C-EN
Installer’s Guide
PAINTED AREAS OF THE UNIT MUST BE SHIELDED
DURING BRAZING.
4. Flow a small amount of nitrogen through the tubing
while brazing.
5. Use good brazing technique to make leakproof
joints.
6. Minimize the use of sharp 90 degree bends.
7. Insulate the suction line and its fittings.
8. Do NOT allow un-insulated lines to come into contact
with each other.
NOTE:
Torque specification for TXV equals 1/6 turn past finger
tight. Make sure to backwrench when tightening as
shown in Firgure 3.
F. LEAK CHECK
1. Using a manifold gauge, connect an external supply
of dry nitrogen to the gauge port on the liquid line.
2. Pressurize the connecting lines and indoor coil to
150 PSIG maximum.
3. Leak check brazed line connections using soap
bubbles. Repair leaks (if any) after relieving
pressure.
4. Evacuate and charge the system per the instructions
packaged with the outdoor unit.
G. CONDENSATE DRAIN PIPING
(SEE FIGURE 5)
NOTE:
When coils are installed above ceilings or in other
locations where damage from condensate overflow
may occur. A field fabricated auxiliary drain pan shall be
installed under the coil enclosure. Drain lines from this
pan must be installed, but should NOT be connected to
the primary drain.
Condensate drain connections are located in the drain pan
at the bottom of the coil/enclosure assembly. The female
threaded fitting protrudes outside of the enclosure for
external connection. A field fabricated trap is not required
for proper drainage due to the positive pressure of the
furnace; however, it is recommended to prevent efficiency
loss of conditioned air.
1. The drain hole in the drain pan must be cleared of all
insulation.
2. Insulate the primary drain line to prevent sweating
where dew point temperatures may be met.
(Optional depending on climate and application
needs).
FIELD FABRICATED TRAP
⑤
2" MIN.
2" MIN.
CAP OR PLUG
Trap must be within 4'
of furnace / air handler
condensate drain connection.
Close as possible
When replacing the bulb and hose clamp, the clamp
should be "snug" but not "tight" - spec is to torque the
hose clamp to 20+/-5in-lb.
H. SECONDARY CONDENSATE DRAIN
A secondary condensate drain connection, now called for
by many building codes, has been provided, on 4TXFH
coils. Reducing fittings and copper tubing can be used in
most cases.
IMPORTANT:
Plug all drain line connection(s) not used. Do NOT use
heat or torch near drain fittings.
I. DUCT CONNECTIONS
The supply and return air duct should be connected to
the unit with a flame retardant duct connectors. Duct
flange connections are provided at both supply and
discharge openings of the coil.
④
1. Remove both sealing rubber plugs from the indoor
coil.
2. Field supplied tubing should be cut square, round
and free of burrs at the connecting end. Clean the
tubing to prevent contaminants from entering the
system.
3. Run the refrigerant tubing into the stub tube sockets
of the indoor unit coil.
