6
Turn the electrical power on, and let the system run for
several minutes. It will take some time for the refrigerant
pressures to stabilize.
If you are using the “Matched Combination”, see the
outdoor unit "Specification Sheet". Compare the operating
pressures and outdoor unit amp draw to the numbers
listed. If pressures and amp draw are too low, add charge.
If pressures and amp draw are too high, remove charge.
If you are not using the “Matched Combination” which is
listed on the unit "Specification Sheet", check subcooling
(TEV coils) or superheat (cap tube or flowrator coils) as
detailed below.
FIINAL CHARGE ADJUSTMENT
(NON-MATCHING SYSTEM—COOLING OPERATION)
EXPANSION VALVE INDOORS:
At stabilized cooling conditions and with an outdoor tem-
perature of 60°F or higher, the system should have from
9°F to 13°F subcooling. For a proper subcooling reading,
measure the refrigerant pressure and temperature at the
outdoor unit liquid line service valve. If you have less than
9°F subcooling, add charge. If you have more than 13°F
subcooling, remove charge.
ORIFICE OR CAP TUBE INDOORS:
For a proper superheat reading, measure the refrigerant
pressure and temperature at the outdoor unit vapor line
service valve. The superheat should be within 3°F of that
shown on the chart below. If the superheat is more than 3
°F higher than shown on the chart, add charge. If the
superheat is more than 3 °F lower than shown on the chart,
remove charge.
4
50
60
70
80
90
100
110
120
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
SUPERH
E
AT
@ O
.D.
U
N
IT
OUTDOOR TEMPERATURE
DESIRED SUPERHEAT vs OUTDOOR TEMPERATURE
90° F
In
do
or
70° F Ind
oo
r
75° F Indo
or
80° F Indo
or
85° F Indo
or
THE RETAINER. TO AVOID LOSS OF REFRIGERANT,
DO NOT APPLY PRESSURE TO THE RETAINER.
The outdoor unit is factory charged with enough R-22 for
the matching indoor blower coil or matching A coil plus 25
feet of 3/8 inch liquid line. Add or subtract 0.60 oz. of R-22
per foot of 3/8" liquid line for any difference from 25 feet.
IMPORTANT: Use only refrigerant which is certified to
meet ARI Standard 700. Used refrigerant may cause
compressor damage, and will void the warranty. (Most
portable machines cannot clean used refrigerant well
enough to meet this ARI Standard.)
IMPORTANT: If adding additional refrigerant to a system,
add only refrigerant vapor (not liquid) through the suction
valve (low side) on the outdoor unit. Any other practice
may cause compressor damage.
FINAL CHARGE ADJUSTMENT
(MATCHING SYSTEM—COOLING OPERATION)
IMPORTANT: Never operate the compressor with the
suction valve closed to “test the compressor’s pumping
efficiency”. In some cases, this can result in serious
compressor damage and loss of warranty coverage.
If installing a non-matching system, the outdoor tempera-
ture must be 60°F or higher to perform the final charge
adjustment.
If the outdoor temperature is 60°F or higher, set the room
thermostat to COOL, fan switch to AUTO, and set the
temperature control well below room temperature.
If the outdoor temperature is below 60°F and you are
installing a matching system, set the room thermostat to
HEAT, fan switch to AUTO, and set the temperature
control well above room temperature. Measure the low
side pressure from the pressure tap provided. See Figure
4. Measure the high side pressure from the liquid line
service valve.
VAPOR LINE
SERVICE VALVE
LIQUID LINE
SERVICE VALVE
LOW SIDE
PRESSURE TAP
Figure 4
