Sharp DW-71-H Service Manual page 29

[Evacuation/gas charge procedure]
Evacuation
(1) Evacuation (5 minutes)
Coolant gas charging (specified amount)
The check valve is provided additionally to prevent back flow of vacuum pump oil. The power supply for the
vacuum pump must not be turned off until the cycle (1)
the specific degree of vacuum.
Follow the procedure shown below.
For R-12 i 1/4
with cap
To power source
Socket (for vacuum pump)
Preparation for coolant charging
(1) Preliminary charge the coolant into the charging cylinder.
Quantity of gas = Specified quantity + 30 g +
Note:
When charging the coolant into the charging cylinder, be sure to discharge the air from the cylinder and hose.
(2) Connect the tools as shown above, and close all the valves.
(3) Connect the start relay and protector of compressor so that the compressor is ready to start.
(4) Follow the procedure (1) to (8) shown in the figure.
Procedure
1 Valve closing
«
Valve opening
4
Purge the inside of
cylinder and hose.
«
5
Valve closing
(2) Coolant charging (approx. 30 g)
Switch ON
)
off on
Check valve for
vacuum pump
Charging hose (10mm)
Reducer ( 3/8,1/4 )
Vacuum pump
for R-12
(retention in piping)
6
Gas side Liquid side
Charging cylinder
for HFC-134a
(3) Evacuation (30 minutes)
(2) (3) shown above is completed so as to attain
Low High
Additional valve opening
pressuer pressuer
Gauge manifold
Valve opening
Valve closing
Liquid side
Gas side
Charging cylinder
for HFC-134a
Charge gas, adijusting valves
2 Valve opening
«
7 Valve closing
Coolant gas cylinder
29
Valve opening
High pressure pipe side
Dehumidifier
Refrigeration cycle
Low pressure pipe side
3-way reducer ( 3/8,3/8,10mm )
Valve closing
3 Valve opening
«
Valve closing
8
DW-71-H
(4)