035-15713-003 REV. A (0500)
6
Unitary Products Group
ORIFICE SELECTION (ON SWEAT FIT COILS)
NOTE:
The proper orifice must be installed in the indoor coil
liquid line connection prior to the connection of the
refrigerant lines.
The orifice shipped with the outdoor unit is based on the
“most sold” combination, but it may be changed, depending
on the capacity and efficiency of the outdoor unit, elevation
differences, and/or long total line lengths. An additional ori-
fice(s) is shipped with most outdoor units for the most com-
monly required replacement combinations. Other sizes must
be ordered from Source 1 Parts if required.
See the appropriate Tabular Data Sheet for the correct orifice
size and charge adder.
If the orifice size matches, nothing fur-
ther is required and the refrigerant lines may be connected
per the outdoor unit instruction. However, if another orifice
should be used, see the coil instruction for details to change
the orifice in the coil.
REFRIGERANT VALVE OPERATION (ON SWEAT
FIT UNITS)
All models in this series have brass service valves. These
valves are not back seating. Opening or closing valve does
not close service port. Service ports have Schrader Valves for
gauge connections. Use back-up wrench on valve body when
removing cap to open or close the valve. To open, insert hex
wrench into stem and back out counter clockwise until stem
just touches retaining ring.
Some units may have factory installed 1-1/8" ball valves. To
open the valve, remove the brass valve stem cap, located on
the side of the valve, with an adjustable wrench. Next, turn
the valve stem 1/4 turn CCW (away from unit).
All caps must be replaced to prevent leaks.
Replace valve cap finger tight, then tighten an additional 1/6
of a turn with a wrench, using a back-up wrench on the valve
body.
OIL TRAPPING
When the outdoor unit is above the indoor coil oil trapping is
necessary. An oil trap should be provided for every 20 feet of
rise.
Check the system for correct charge after all components of
the system have been installed, connected and wired cor-
rectly.
Connect service gauges to low pressure port and discharge
service ports.
Allow unit to operate until system pressures and tempera-
tures have stabilized, making sure that the pressure and tem-
perature align with unit service data. If not, check system
charge and adjust if necessary.
Coil is under 30 to 35 psig (inert gas) pressure.
Each coil has an orifice installed in the fitting
between the liquid line connection and distributor.
The orifice is identified on a label next to the liquid
line connection.
All outdoor units are shipped with the service valves
in the closed position. After installation of the refrig-
erant and proper evacuation, make sure that all
valves are in the open position and that the caps are
securely tightened before turning ON the electrical
power to the outdoor unit.
If the valve stem is backed out beyond the retaining
ring, system pressure could force the stem out of the
valve body and possibly cause personal injury. In
the event that the retaining ring is missing do not
attempt to open the valve.
Do not under any circumstance connect refrigeration
gauges or refrigerant cylinders to the vapor line ser-
vice valve (large) gauge port. Personal injury could
result if the system is operating in the heating mode.
When checking pressures use the gauge port
located on the liquid service valve and the gauge
port located to the right of the vapor line service
valve, marked low pressure port.
FIGURE 4 :
OIL TRAP
