Evacuation - York 18 Seer-CZH Series Installation Manual

2. Remove the cap and Schrader core from both the liquid and vapor
service valve service ports at the outdoor unit. Connect low pressure
nitrogen to the liquid line service port.
3. Braze the liquid line to the liquid valve at the outdoor unit. Be sure to
wrap the valve body with a wet rag. Allow the nitrogen to continue
flowing.
4. Relieve the holding charge from the indoor coil by depressing the
Schrader valve stem located in the end of the suction line. Cut the
spundown copper to allow installation of the suction line.
FIGURE 4: Heat Protection
The evaporator is pressurized.
5. If TXV has not been installed refer to Page 3 "TXV INSTALLA-
TIONS".
6. Braze the liquid line to the evaporator liquid connection. Nitrogen
should be flowing through the evaporator coil.
7. 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.
a. 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. For detailed instructions, refer
to the Installation Instructions accompanying the TXV kit.
b. Bulb should be installed on a horizontal run of the vapor line if
possible. The bulb should be installed on top of the line.
c. If bulb installation is made on a vertical run, the bulb should be
located at least 16 inches from any bend, and on the tubing 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.
d. Bulb should be insulated using thermal insulation provided to pro-
tect it from the effect of the surrounding ambient temperature.
Cover completely to insulate from air-stream.
In all cases, mount the TXV bulb after vapor line is brazed and has
had sufficient time to cool.
Johnson Controls Unitary Products
8. Protect the vapor valve with a wet rag and braze the vapor line con-
nection to the outdoor unit. The nitrogen flow should be exiting the
system from the vapor service port connection. After this connection
has cooled, remove the nitrogen source from the liquid fitting service
port.
9. Replace the Schrader core in the liquid and vapor valves.
10.Leak test all refrigerant piping connections.
NOTICE
Line set and indoor coil can be pressurized to 250 psig with dry
nitrogen and leak tested with a bubble type leak detector. Then
release the nitrogen charge.
NOTICE
Do not use the system refrigerant in the outdoor unit to purge or
leak test.
Never attempt to repair any brazed connections while the system is
under pressure. Personal injury could result.
SECTION IV: EVACUATION
1. 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 indica-
tion 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 evacu-
ation if the reading is above 500 microns.
2. While system is being evacuated proceed to SECTION V "ELEC-
TRICAL CONNECTIONS". System charging will be covered under
SECTION VI "SYSTEM CHARGE"
SECTION V: ELECTRICAL CONNECTIONS
GENERAL INFORMATION & GROUNDING
Check the electrical supply to be sure that it meets the values specified
on the unit nameplate and wiring label.
Power wiring, control (low voltage) wiring, disconnect switches, and
over current protection must be supplied by the installer. Wire size
should be sized per NEC requirements.
All field wiring must USE COPPER CONDUCTORS ONLY and be
in accordance with Local, National, Fire, Safety, & Electrical Codes.
This unit must be grounded with a separate ground wire in accor-
dance with the above codes.
The complete connection diagram and schematic wiring label is located
on the inside surface of the unit service access panel.
835965-UIM-A-0112
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