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IM 820
Page 17
Evacuating and Charging
Evacuating the tubing and the indoor unit
The outdoor unit is pre-charged with refrigerant R-22. The
indoor unit and the refrigerant connection tubing must be
evacuated as follows:
1.
Remove the 3 caps from the valves on the outdoor unit.
2. Connect the center of the charging gauge to the
vacuum pump.
3. Connect the charging gauge to the service port of the
3-way valve (
See Figure 9
).
4. Start the pump and evacuate to -760 mm Hg (-29.9" Hg).
5. Close the valve of the changing gauge and stop the
vacuum pump.
6. On the outdoor unit, open both valves using a 4 mm
Allen wrench (
See Figure 8
).
Figure 8. 3-way Suction Valve on Outdoor Unit
Figure 9 Evacuation Schematic
Additional charge
The refrigerant is pre-charged in the outdoor unit. If the tub-
ing length between the indoor and outdoor unit is no more
than 25 ft.
,
then an additional charge after evacuation is not
necessary. If the tubing length is more than 25 ft., use addi-
tional R-22 as indicated in
Table 7
.
Table 7: Additional R-22 ounces per foot of tubing
(when tubing length is more than 25 ft.) and maximum
tubing length.
Charge operation
This operation must be done by weighing the R-22 being
added thru the service port on the 3-way suction valve.
See Table 7 and Figure 10.
1.
Remove the service port cap.
2. Connect the low pressure side of the charging gauge to
the suction service port center of the cylinder tank and
close the high pressure side of the gauge. Purge the air
from the service hose
(See Figure 10)
.
3. Start the air conditioner unit.
4. Open the gas cylinder and low pressure charging valve.
5. When the required refrigerant quantity is pumped into
the unit, close the low pressure side and the gas cylinder
valve.
6. Disconnect the service hose from service port. Put back
the service port cap.
Figure 10. Charging Schematic
Hex Socket
for 4 mm
Allen wrench
Flare Nut
Refrigerant
Tubing
Service
Port
Outdoor Unit
3-way Valve
Indoor Unit
Liquid side
Outdoor Unit
Close
Discharge Valve
Suction Valve
Close
Gas side
Vacuum
Pump
High
Press.
Low
Press.
Model
Oz. Per ft.
Max. Length
20D
.16
49’
25D
.40
49’
30D
.53
115’
40D
.55
115’
50D
.55
115’
20DR
.16
49’
25DR
.50
49’
30DR
.53
115’
40DR
.55
115’
50DR
.55
115’
Indoor Unit
Outdoor Unit
Liquid side
Gas side
High
Press.
Low
Press.
Discharge Valve
Suction Valve