18-AD28D1-2
7
Installer’s Guide
K. BRAZING TO EVAPORATOR SECTION
IMPORTANT:
Do not unseal refrigerant tubing until ready to cut and fit
refrigerant 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 seals from the indoor coil. The braze caps
are soft soldered.
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. Braze and evacuate according to indoor and outdoor instal-
lation instructions.
5. Flow a small amount of nitrogen through the tubing while
brazing.
6. Use good brazing technique to make leakproof joints.
7. Minimize the use of sharp 90 degree bends.
8. Insulate the suction line and its fittings.
9. Do NOT allow un-insulated lines to come into contact with
each other.
▲
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.
I. INSTALLING REFRIGERANT LINES
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 limita-
tions.
NOTE:
Large diameter tubing sizes will be difficult to bend once
it has been shaped.
c. Determine the best starting point for routing the refrigerant
tubing --INSIDE OR OUTSIDE THE STRUCTURE.
d. Provide a pull through hole of sufficient size to allow both
liquid and gas lines to clear. The location of this hole (if prac-
tical) should be just above the wall plate which is resting on
the foundation.
e. Be sure the roll of tubing is of sufficient length.
f. Uncoil the tubing - do not kink or dent.
g. Route the tubing making all required bends and properly
secure the tubing before making final connections.
NOTE: These lines must be isolated from the structure and
the holes must be sealed weather tight after installation.
J. FIELD FABRICATED INTERCONNECTING LINES
1. The following procedure should be used for connecting
tubing to the coil or the Outdoor Unit.
2. More information concerning the installation of refriger-
ant lines is covered in the Installers Guide packaged with the
outdoor unit. Evacuation, leak testing and brazing procedures
are included in those instructions before starting the instal-
lation of refrigerant lines.
Maximum airflow setting, CFM
Coil
Horizontal
Left
Horizontal
Right
Downflow
4NXCA018AC3HCA
4NXCA024AC3HCA
900
900
800
4NXCB025AC3HCA
4NXCB031AC3HCA
1125
1125
1000
4NXCB032AC3HCA
4NXCB036AC3HCA
1200
1350
1200
4NXCD063BC3HCA
2250
2250
1750
H. MAXIMUM AIRFLOW SETTING, CFM
NOTE:
Water blow-off could occur in certain installation posi-
tions if the airflow setting exceeds the maximum values
listed.
