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CAUTION
!
Dry nitrogen should always be supplied through the tubing while it is
being brazed, because the temperature required is high enough to
cause oxidation of the copper unless an inert atmosphere is provided.
The flow of dry nitrogen should continue until the joint has cooled.
Always use a pressure regulator and safety valve to insure that only
low pressure dry nitrogen is introduced into the tubing. Only a small
flow is necessary to displace air and prevent oxidation.
NOTICE
Avoid handling aluminum coil components after handling the copper
line set or other tubing without first cleaning hands.
Connect lines as follows:
NOTICE
Route the refrigerant lines to the coil in a manner that will not obstruct
service access to the coil, air handling system, furnace flue or filter.
1. Suction and liquid line connections are made outside the cabinet.
Leave the tubing connection panel attached to the cabinet. Coil
access panel should be removed for brazing. The lines are
expanded to receive the field line set tubes for most outdoor unit
matches.
2. Remove grommets where tubes exit the cabinet to prevent burning
them during brazing. In some units, the vapor line grommet may be
shipped as a loose part with the unit. Refer to Figure 13.
3. Cut the end of the suction tube using a tube cutter. Place the tube
cutter as close as possible to the end of the tube to allow as much
depth as possible for the connection and brazing of the suction line.
To ensure suction line fits into connection, deburr the stub out
(including inner pressure protrusion from cutting).
4. If coil does not have a factory installed TXV or EEV, install the
required size piston or TXV kit. See coil metering devices section
for detailed instructions.
5. If the coil does have a factory installed TXV or EEV, remove the liq-
uid line copper c ap which is soft soldered onto the outside of the
3/8" stub protruding from front of the coil cabinet tubing panel as fol-
lows:
a.
Screw a sheet metal screw into the center of the cap.
b.
Apply a small amount of heat to the cap while pulling on the
screw using slip joint pliers.
IMPORTANT
FOR EEV EQUIPPED COILS ONLY
The EEV in this unit is shipped in the closed position to protect the
valve during transportation. Prior to brazing, the following steps must
be taken: 1. Connect the communication cable from the coil to the
communication port on the furnace or modular blower control board.
2. Connect and apply line power to the field wiring terminals of the fur-
nace or modular blower and ensure the board is powered for 60 sec-
onds. This will ensure the EEV control board cycles the valve to an
open position. This will allow nitrogen to flow through the system
during brazing.
NOTICE
If power cannot be applied to the EEV control board prior to brazing
refrigeration piping, a tool is available to manually operate the EEV.
An EEV manual operating tool can be purchased from Source 1 as
part number S1-02649686000. Six revolutions of the tool will open
the valve fully.
Johnson Controls Unitary Products
6. Insert liquid and suction lines into the coil connections at the coil
cabinet tubing panel.
7. Wrap a water soaked rag around the coil connection tubes inside
the cabinet to avoid transferring excess heat to the coil, TXV, EEV
and temperature sensor if EEV equipped.
8. Purge refrigerant lines with dry nitrogen.
NOTICE
All indoor coil connections are copper-to-copper and should be
brazed with a phosphorous-copper alloy material such as Silfos-5 or
equivalent. DO NOT use soft solder.
9. Braze the suction and liquid lines, and allow the joints to cool.
10. If TXV is used, route the TXV sensing bulb through suction line
opening. On EEV equipped coils, route the EEV control communi-
cating cable through the suction line opening.
11. Secure sensing bulb and equalizer line capillary tubes with nylon
cable ties to prevent leaks from tubes rubbing.
12. If piston is used, install Schrader core into suction header, and rein-
stall cap.
13. Re-attach the grommets to the lines carefully to prevent air leak-
age. In some units, the vapor line grommet may be shipped as a
loose part with the unit. Refer to Figure 13.
14. Refer to Outdoor unit Installation Manual, and accomplish evacua-
tion, leak check and charging instructions. Check all field brazed
joints and metering device connections.
15. Attach the coil access panel to the cabinet.
16. Ensure lines are sound isolated by using appropriate hangers or
strapping.
FIGURE 13: Vapor Line Grommet
SECTION VIII: COIL METERING DEVICES
A piston or a TXV (flex coil models) is to be installed in the field. There
is an installation manual that comes with the TXV kit. It is recommended
to install the piston or TXV kit prior to installation of coil and brazing of
line set. Until brazing is completed and cooled, the TXV sensing bulb
must not be installed.
The outdoor technical guide for outdoor units should be consulted for
required piston or TXV on the indoor coil. The piston and the Schrader
core are supplied with the outdoor unit. If a piston is used in lieu of a
TXV, the Schrader core must be installed in the suction line equalizer
connection port and capped with the supplied plastic cap. The Schrader
core must not be installed if the TXV is installed, as the TXV equalizer
line attaches to the equalizer connection port.
5292154-UIM-A-0317
7
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