5320779-UIM-A-0417
Johnson Controls Unitary Products
5
4.
Braze the liquid line to the evaporator liquid connection. Nitrogen
should be flowing through the evaporator coil.
5.
Slide the grommet away from the vapor connection at the indoor
coil. Braze the vapor line to the evaporator vapor connection. After
the connection has cooled, slide the grommet back into original
position.
6.
Protect the vapor valve with a wet rag and braze the vapor line
connection to the outdoor unit. The nitrogen flow should be exiting
the system from the vapor service port connection. After this con-
nection has cooled, remove the nitrogen source from the liquid fit-
ting service port.
7.
Replace the Schrader core in the liquid and vapor valves.
8.
Go to “SECTION IV” or “SECTION V” for orifice or TXV installation
depending on application.
9.
Leak test all refrigerant piping connections including the service
port flare caps to be sure they are leak tight. DO NOT OVER-
TIGHTEN (between 40 and 60 inch - lbs. maximum).
10. Evacuate the vapor line, evaporator, 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 both the liq-
uid and vapor valves by removing the plunger cap and with an
allen wrench back out counter-clockwise until valve stem just
touches the chamfered retaining wall. If the service valve is a ball
valve, use a Crescent 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.
Supplied with the outdoor unit is a Schrader Valve Core and Orifice for
highest sales volume indoor coil. The valve core must be installed in
equalizer fitting of the indoor coil.
SECTION IV: TXV INSTALLATION
The following are the basic steps for installation. For detailed instruc-
tions, refer to the Installation Instructions accompanying the TXV kit.
Install TXV kit as follows:
1.
Relieve the holding charge by pulling off the rubber cap plug on
the suction manifold line of the coil.
2.
After holding charge is completely discharged, loosen and remove
the schrader cap seal.
3.
Loosen and remove distributor cap seal.
4.
Install the thermal expansion valve to the orifice distributor assem-
bly with supplied fittings. Hand tighten and turn an additional 1/4
turn to seal. Do not overtighten fittings.
5.
Install the liquid line to the top of the thermal expansion valve with
fitting supplied with the liquid line. Hand modify the liquid line to
align with casing opening. Hand tighten the liquid line and an addi-
tional 1/4 turn to seal.
6.
Install the TXV equalizer line into the vapor line as follows:
a.
Hand tighten the 1/4” SAE nut to the schrader fitting and an
additional 1/3 turn to seal.
7.
Install the TXV bulb to the vapor line near the equalizer line, using
the bulb clamp(s) furnished with the TXV assembly. Ensure the
bulb is making maximum contact.
a.
Bulb should be installed on a horizontal run of the vapor line if
possible. The bulb should be installed on top of the line.
b.
If bulb installation is made on a vertical run, the bulb should
be located at least 16 inches from any bend, and on the tub-
ing sides opposite the plane of the bend. The bulb should be
positioned with the bulb tail at the top, so that the bulb acts as
a reservoir.
c.
Bulb should be insulated using thermal insulation provided to
protect it from the effect of the surrounding ambient tempera-
ture. Cover completely to insulate from air-stream.
SECTION V: EVACUATION
It will be necessary to evacuate the system to 500 microns or less. If a
leak is suspected, leak test with dry nitrogen to locate the leak. Repair
the leak and test again.
To verify that the system has no leaks, simply close the valve to the
vacuum pump suction to isolate the pump and hold the system under
vacuum. Watch the micron gauge for a few minutes. If the micron
gauge indicates a steady and continuous rise, it’s an indication of a
leak. If the gauge shows a rise, then levels off after a few minutes and
remains fairly constant, it’s an indication that the system is leak free but
still contains moisture and may require further evacuation if the reading
is above 500 microns.
CAUTION
Do not install any coil in a furnace which is to be operated during the
heating season without attaching the refrigerant lines to the coil. The
coil is under 30 to 35 psig inert gas pressure which must be released
to prevent excessive pressure build-up and possible coil damage.
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.
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IMPORTANT
Only 1TVM4** series valves are to be used on TCHD.
Only 1TVMB** series valves are to be used on TCHE.
CAUTION
In all cases, mount the TXV bulb after vapor line is brazed and has
had sufficient time to cool.
WARNING
Schrader valve core MUST NOT be installed with TXV installation.
Poor system performance or system failure could result.
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