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HPXA16 SERIES
HPXA16 Cooling Cycle (Showing Gauge Manifold Connections)
Figure 17
NOTE
− Use gauge ports on vapor line valve and liquid valve for evacuating refrigerant lines and indoor coil. Use vapor
gauge port to measure vapor pressure during charging.
OUTDOOR
COIL
EXPANSION/
CHECK VALVE
BIFLOW
FILTER /
DRIER
TO
HFC−410
A DRUM
LOW
PRESSURE
COMPRESSOR
REVERSING VALVE
VAPOR
LINE
VALVE
MUFFLER
NOTE − ARROWS INDICATE
DIRECTION OF REFRIGERANT FLOW
SERVICE
PORT
VAPOR
EXPANSION/CHECK VALVE
INDOOR UNIT
OUTDOOR UNIT
LIQUID
LINE
SERVICE
PORT
GAUGE MANIFOLD
DISTRIBUTOR
INDOOR
COIL
VAPOR
SERVICE
PORT
HUGH
PRESSURE
Table 3
Refrigerant Charge per Line Set Lengths
Liquid Line
Set Diameter
Ounces per 5 feet (grams per 1.52 meter)
adjust from 15 ft. (4.57m) line set*
3/8 in. (9.5mm)
3 ounces per 5 feet (85 grams per 1.52 meter)
*Add the amount shown if line length is greater than 15’ (4.57m), sub-
tract the amount shown if less than 15’.
IMPORTANT
Mineral oils are not compatible with HFC−410A. If
oil must be added, it must be a polyol ester oil.
The compressor is charged with sufficient polyol
ester oil for approved line set lengths.
Checking Charge
The outdoor unit should be charged during warm weather.
However, applications arise in which charging must occur
in the colder months.
The method of charging is deter-
mined by the outdoor ambient temperature
.
Measure the liquid line temperature and the outdoor ambi-
ent temperature as outlined below:
1. Connect the manifold gauge set to the service valves:
low pressure gauge to
vapor
valve service port
high pressure gauge to
liquid
valve service port
Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HFC−410A. See
figure 17.
2. Set the room thermostat to call for heat. This will
create the necessary load for properly charging the
system in the cooling cycle.
3. Record outdoor ambient temperature using a digital
thermometer.
4. When the heating demand has been satisfied, switch
the thermostat to cooling mode with a set point of 68
F
(20
C). When pressures have stabilized, use a digital
thermometer to record the liquid line temperature.
5. The outdoor temperature will determine which charg-
ing method to use. Proceed with whichever of the fol-
lowing charging procedure deemed appropriate for the
situation.
Charge Using the Weigh-in Method –
Outdoor Temperature < 65
F (18
C)
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, first, locate and repair any leaks and
then weigh in the refrigerant charge into the unit.
1. Recover the refrigerant from the unit.
2. Conduct leak check; evacuate as previously outlined.
3. Weigh in the unit nameplate charge. If weighing facili-
ties are not available or if charging the unit during
warm weather, use one of the following procedures.
Charge Using the Subcooling Method –
Outdoor Temperature < 65°F (18°C)
When the outdoor ambient temperature is below 65°F
(18°C), use the subcooling method to charge the unit. It
may be necessary to restrict the air flow through the out-
door coil to achieve pressures in the 325−375 psig
(2240−2585 kPa) range. These higher pressures are nec-
essary for checking the charge. Block equal sections of air
intake panels and move obstructions sideways until the liq-
uid pressure is in the 325−375 psig (2240−2585 kPa) range.
See figure 18.
Blocking Outdoor Coil
*Outdoor coil should be blocked one
side at a time with cardboard or plastic
sheet until proper testing pressures
are reached.
cardboard or plastic sheet
*Four−sided unit shown.
Figure 18