18-AD42D1-1B-EN
5
Installer’s Guide
IMPORTANT:
Do not unseal refrigerant tubing until ready to fit refriger
-
ant lines.
There is only a holding charge of dry air in the indoor coil, therefore
no loss of operating refrigerant charge occurs when the sealing
plugs are removed.
NOTE:
TXV bulb MUST be protected (wrapped with wet rag) or
removed, while brazing the tubing. Overheating of the
sensing bulb will affect the functional characteristics and
performance of the comfort coil.
1. Remove both 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.
PAINTED AREAS OF THE UNIT MUST BE SHIELDED
DURING BRAZING.
4. Flow a small amount of nitrogen through the tubing while
brazing.
H. MAXIMUM AIRFLOW SETTING (CFM)
NOTE:
Water blow-off could occur in certain installation
positions if the airflow setting exceeds the maximum
values listed.
Maximum airflow settings (CFM)
Coil
Upflow Downflow
Horizontal
Left
Horizontal
Right
4TXCB004DS3HCC
1350
1100
1200
1350
4TXCD010DSCHCC
2250
1850
2000
2250
NOTE:
The TXV setting on this unit may run high superheat
(15-25°F) by design when measured at the outdoor unit.
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.
When replacing the TXV bulb, reinstall the bulb in the
proper orientation.
9. Wrap the TXV with insulation after the spring clip has been
installed.
J. 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.
K. 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 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)
3. Connect the secondary drain line to a separate drain line
(no trap is needed in this line).
Figure 13
Capillary tubes will come
out the top of bulb when
positioned correctly.
I. INSTALLING/BRAZING REFRIGERANT LINES
CAUTION
!
Do NOT open refrigerant valve at the outdoor unit until the
refrigerant lines and coil have been brazed, evacuated, and
leak checked. This would cause contamination of the refriger-
ant or possible discharge of refrigerant to the atmosphere.
1. The following steps are to be considered when installing
the refrigerant lines:
a. Determine the most practical way to run the lines.
b. Consider types of bends to be made and space
limitations.
c. Route the tubing making all required bends and
properly secure the tubing before making final
connections.
NOTE:
Refrigerant lines must be isolated from the structure and
the holes must be sealed weather tight after installation.
