9
Refrigerant Charging
and Evacuation
Caution
• Freon Gas “R22” only.
• Always evacuate air from the tubing
before adding refrigerant.
• Add refrigerant through the
charging port of liquid line valve
after the completion of evacuation.
• The refrigerant provided by the
manufacturer meets all the
requirements of our units. When
using recycled or reprocessed
refrigerant, it is advisable to ensure
its quality is equivalent to that of a
new refrigerant. For this, it is
necessary to have a precise
analysis made by a specialized
laboratory. If this condition is not
respected, the manufacturer’s
warranty could be cancelled.
Liquid Charging
After the refrigerant pipework system
has been pressure tested and
evacuated, the refrigerant may be
charged as follows.
1. Weigh the refrigerant cylinder on
weighing scale.
2. Attach the charging line from the
center hose of manifold gauge to
R-22 cylinder.
3. Open valve on R-22 cylinder and
purge the charging line.
4. Invert the refrigerant cylinder, open
the liquid line service valve. Open
manifold valve so that only liquid
will enter the system. The sufficient
operating charge is recommended
in Table 3.
Gaseous Charging
This procedure is accomplished
with the unit operating. Electrical
connections must be complete.
Do not proceed until the system is
ready to operate.
Procedure
1. Open liquid valve that refrigerant
go through air handler unit and
open suction valve.
2. Turn on power to the unit. Allow the
system to run for five to ten
minutes to stabilize operating
conditions.
3. Measure airflow across the indoor
coil. Compare the measurements
with the fan performance data
in the Data/Submittal or Service
Facts. Once proper airflow is
established, observe the suction
and head pressure gauges on the
gauge manifold.
Suction Line Service Valve
Suction Line Gauge Port
Liquid Line Service Valve
Liquid Line
Gauge Port
Manifold
Gauges
Figure 3
Pressure reading should fall
approximately at the points shown
by the pressure curves in Service
Facts. Add or remove refrigerant
(gas only) as required to obtain
correct head and suction pressure.
Check suction line superheat and
condenser sub-cooling to ensure
the unit is operating properly.
4. Disconnect all power to the unit.
5. Remove the charging system from
the unit and close the opening in
the bottom of the control box with
the pivotal cover before attempting
to replace access panel.
6. Replace all panels.
Additional Charge
Refrigerant suitable for a tube length
of 12 to 25 feet is recommended in
Table 3. When the tube is longer than
25 feet, additional charging is
necessary. For the additional amount,
using the table 4 for recommended
amounts:
TTA-IOM-EN0110
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