5390862-UIM-A-0318
6
Johnson Controls Unitary Products
10. Evacuate the vapor line, indoor coil, and liquid line to 500 microns
or less.
11. Replace cap on service ports. Do not remove the flare caps from
the service ports except when necessary for servicing the system.
12. Release the refrigerant charge into the system. Open the liquid
valve by removing the plunger cap and turning the valve stem out
counter-clockwise until valve stem just touches the chamfered
retaining wall. Repeat this procedure for the vapor line valve. If the
service valve is a ball valve, use an adjustable end wrench to turn
valve stem one-quarter turn counterclockwise to open. Do not
overturn or the valve stem may break or become damaged. See
“PRECAUTIONS DURING BRAZING SERVICE VALVE”.
13. Replace plunger cap finger tight, then tighten an additional 1/12
turn (1/2 hex flat). Cap must be replaced to prevent leaks.
See “System Charge” section for checking and recording system
charge.
SECTION IV: COIL METERING DEVICES
A TXV is to be installed in the field. There is an installation manual that
comes with the TXV kit. It is recommended to install the 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 TXV on the indoor coil. Check that there is no Schrader valve
core installed in equalizer line fitting on the indoor coil suction header.
TXV will not function properly if a Schrader valve core is installed.
THERMOSTATIC EXPANSION VALVE (TXV)
INSTALLATION
The following are basic steps for installation. For detailed instructions,
refer to the Installation Instructions accompanying the TXV kit. Install
TXV kit as follows:
1. Relieve the holding charge by depressing Schrader core on the
suction manifold stub out.
2. After holding charge is completely discharged, loosen and remove
the Schrader core.
3. Place a backup wrench on distributor, loosen and remove brass
distributor nut. Retain brass nut for use on liquid line. Keep Teflon
washer in place and discard distributor seal disk.
4. Install the thermal expansion valve to the distributor assembly with
supplied fittings. Ensure Teflon washer is seated in distributor.
Hand tighten and turn an additional 1/4 turn to seal. Do not over-
tighten fittings. See Figure 6.
5. Slide the nut removed in step 3 over the supplied liquid line. Place
supplied Teflon washer from TXV kit in place on TXV, and install liq-
uid line to the top of the thermal expansion valve. Adjust assembly
so liquid line aligns with hole in access panel. Hand tighten the liq-
uid line, and apply an additional 1/4 turn to seal.
6. Install the TXV equalizer line onto the vapor line by hand tightening
the 1/4” SAE coupling nut to the equalizer fitting, and apply an addi-
tional 1/3 turn to seal. See Figure 7.
NOTICE
Line set and indoor coil can be pressurized to 250 psig with dry nitro-
gen and leak tested with a bubble type leak detector. Then release
the nitrogen charge.
Do not use the system refrigerant in the outdoor unit to purge or leak
test.
CAUTION
Do not connect manifold gauges unless trouble is suspected. Approx-
imately 3/4 ounce of refrigerant will be lost each time a standard man-
ifold gauge is connected.
WARNING
Never attempt to repair any brazed connections while the system is
under pressure. Personal injury could result.
CAUTION
COIL UNDER PRESSURE.
Verify that pressure has been released by depressing Schrader valve
core.
The coil requires a metering device to be added.
See outdoor unit documentation for correct TXV to be used.
NOTICE
To prevent moisture and contaminates from entering the system, the
coil should not be open to atmosphere for extended periods of time. If
the coil cannot be brazed into the refrigeration system during a rou-
tine installation period, the ends should be temporarily closed or
plugged. For a short term delay, use masking tape over the ends of
the copper tubing to close the tube from the air. For a longer term
delay, use plugs or caps. There is no need to purge the coil if this pro-
cedure is followed.
!
!
!
CAUTION
Outdoor unit model numbers ending with an “H” have a factory
installed hard start kit which is required when a TXV is installed. Out-
door unit model numbers with no “H” ending do not require a hard
start kit unless local regulations dictate it.
IMPORTANT
Refer to the Technical Guide for the unit to determine the proper TXV
kit to be used on this product.
CAUTION
Do not over-torque. Do not use slip joint pliers. This will distort the
aluminum distributor and the brass fitting (potentially causing leaks).
FIGURE 6:
TXV Installation
WARNING
Schrader valve core MUST NOT be installed with TXV installation.
Poor system performance or system failure could result.
!
!
T
X
V
/
D
I
STR
IB
UTOR
COUP
LING
LI
QU
I
D
LIN
E
/
T
X
V
COUP
LING
TE
FL
O
N W
ASHER
T
X
V
TE
FL
O
N W
ASHER
D
I
STR
IB
UTOR
A
0281-002
!