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1. Rotate fan to check for frozen bearings or binding.
2. Inspect all factory- and field-installed wiring for loose
connections.
3. After evacuation is complete, open the liquid line and
vapor
line
service
valves
(counterclockwise)
to
release refrigerant charge (contained in outdoor unit)
into the system.
4. Replace stem caps and secure finger tight, then
tighten an additional (1/6) one-sixth of a turn.
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit
nameplate. If not, do not start the equipment until the
power company has been consulted and the voltage
condition has been corrected.
6. Set the thermostat
for a cooling demand. Turn on
power to indoor blower unit and close the outdoor unit
disconnect to start the unit.
7. Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.
The unit is factory charged with the amount of HCFC-22
refrigerant indicated on the unit rating plate. This charge is
based on a matching indoor coil and outdoor coil with a 15
foot (4.6 m) line set. For varying lengths of line set, refer to
table 4 for refrigerant charge adjustment.
Table 4. Refrigerant Charge per Line Set Lengths
LiquidLine
Oz. per 5 ft. (g per 1.5m) adjust from
Set Diameter
15 ft. (4.6m) line set*
3/8 in. (9.5mm)
3 ounce per 5 ft. (85g per 1.5m)
NOTE - *If line length is greater than 15 ft. (4.6 m), add this amount, If
line length is less than 15 ft. (4.6 m), subtract this amount.
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
determined by the unit's refrigerant metering device and
the outdoor
ambient
temperature.
Measure the liquid line temperature
and the outdoor
ambient temperature as outlined below:
1, Close
manifold
gauge
set valves.
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
2, Connect
the center manifold
hose to an upright
cylinder of HCFC-22.
3, Set the room thermostat
to call for heat. This will
create the necessary load for properly charging the
system in the cooling cycle,
4, Use a digital thermometer
to record the outdoor
ambient temperature,
5, 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.
6, The
outdoor
temperature
will
determine
which
charging method to use, Proceed with the appropriate
charging procedure,
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
facilities 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
outdoor coil to achieve pressures
in the 200-250 psig
(1379-1724
kPa) range. These
higher pressures
are
necessary for checking the charge. Block equal sections d
air intake panels and move obstructions sideways until the
liquid pressure is in the 200-250 psig (1379-1724
kPa)
range. See figure 21.
Model
oF
(°C)*
*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 21. Blocking Outdoor Coil
1. With the manifold gauge hose still on the liquid service
port and the unit's pressure stabilized, use a digital
thermometer to record the liquid line temperature.
2. At the same time, record the liquid line pressure reading.
3. Use a temperature/pressure
chart for HCFC-22 to
determine the saturation temperature for the liquid line
pressure reading.
4. Subtract the liquid line temperature from the saturation
temperature
(according
to the chart) to determine
subcooling.
5. Compare the subcooling value results with those in
table 5. If subcooling is greater than shown, recover
some refrigerant. If subcooling is less than shown, add
some refrigerant.
Table 5. HP13 Subcooling
Values
o
Saturation Temperature °F (°C)
o
Liquid Line Temperature °F (°C)
o
Subcooling Value °F (°C)
-018
-024
-030
-036
-042
-048
6
11
8
6
6
4
(3.3)
(6)
(4.4)
(3.3)
(3.3)
(2.2)
NOTE - For best results, use the same electronic thermometer to
check both outdoor-ambient
and liquid-line temperatures.
*F: +/-1 .O°; C: +/-0.5 °
-060
9
(5)
Page 13
HP13
SERIES
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