Sharp DW-71-H Service Manual page 27

2.Others
1. Do not use any tools for HFC-134a (for refrigerator) other than common-use tools shown in the list above.
Otherwise adverse influence upon the refrigerator performance may occur.
3. Before brazing replace the air with nitrogen (so as to prevent clogging of capillary tube by oxide scale).
4. So as to improve accuracy of vacuum, provide the vacuum pump port on the gauge manifold and to install
additionally a valve here which prevents entry of incompressible gas (air). For the dehumidifier, install additionally
also the vacuum pump adapter (check valve) so as to prevent entry of oil of vacuum pump (into the refrigerating
cycle).
5. The following cycle is executed through the piping shown below so as to shorten the servicing time.
Primary evacuation (5 min)
charging (specified quantity).
(Vacuum of secondary evacuation must be at least 1 Torr or below.)
In case of primary charge charge the coolant from the low pressure side, and discharge from the high pressure
side. In case of secondary charge charge from the high pressure side.
Caution
1. When evacuating, be sure to use the check valve.
2. All the connections of tools for dehumidifier use 10 mm screws.
Socket
(for vacuum pump)
Cap(1/4)
Vacuum pupm
Gas charging (approx. 30 g)
Additional valve
Check valve
(vacuum pump)
Charging hose
Reducer 3/8, 1/4
To low pressure pipe
HFC-134a
Coolant cylinder
7 kg/cm port 10mm
2
with cap
Secondary evacuation (30 min)
Gauge manifold
Low High
pressuer
pressuer
Coupler
To high pressure pipe
Cap(3/8)
3-way reducer 3/8,3/8,10mm
Liquid side
Charging cylinder
Nitrogen blow pressure regulator
Nitrogen gas
27
For dehumidifier
HFC-134a
Cap(10mm)
Common to refrigerator
DW-71-H
Gas