8
18-AD28D1-2
Installer’s Guide
L. 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 pack-
aged with the outdoor unit.
M. CONDENSATE DRAIN PIPING
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 required in this line.
See Figure 18.
1. The drain hole in the drain pan must be cleared of all
insulation.
2. Insulate the drain line to prevent sweating and dripping.
It is always recommended that an auxiliary drain pan be in-
stalled under a horizontally installed evaporator coil or 90%
gas furnace. Connect the auxiliary drain line to a separate
drain line (no trap is needed in this line).
Field fabricated trap
2" MIN.
2" MIN.
CAP OR PLUG
Trap must be within 4'
of furnace / air handler
condensate drain connection.
Close as possible
Figure 18
Figure 19
Figure 20
N. CLEANING THE COIL
The two piece door (3-piece on 24.5" wide models) allows
removal of the outer casing doors without interference from
refrigerant or condensate lines. Once the outer doors are
removed the split inner coil panels can be easily removed.
The inside and outside of the coil can be easily cleaned with
a brush and vacuum with the panels removed. See Figure 19.
The foil covered insulation on 4NXC coils should be wiped
down and residual dirt and dust should be vacuumed up to
maintain good air quality. See Figure 20.
