Sharp DW-71-H, Service Manual, Page: 33 / 40

33
DW-71-H
(18) Ascertain that the high pressure gauge indicates 1.0 kgf/cm
2
G or above, tight close the high pressure side service
pipe with the pinching jig, remove the gauge manifold, and braze the front end of pipe.
(If the pipe is tight closed when the high pressure gauge pressure is below 1.0 kgf/cm
2
G, air may be sucked in.)
(19) Start the refrigeration cycle compressor, feed the gas from the charging hose and gauge manifold into the cycle.
Close the low pressure valve at low pressure 1.0 kgf/cm2G, and stop the compressor.
(20) Tight close the low pressure side service pipe, remove the gauge manifold, and braze the front end of pipe.
Ascertain that the gauge pressure is higher than 1.0 kgf/cm
2 G.
(21) Run the compressor, and check cooling.
(Ascertain that the temperature of discharge pipe and condenser rises.)
«
on off
Check valve for
vacuum pump
Vacuum pump
for R-12
Valve opening
Valve closing
Valve closing Valve closing
Valve closing
Tight close the servise pipe,
and braze the front end.
Tight close the servise pipe,
and braze the front end.
Valve closing
1
2
3
4
5
Low
pressuer High
pressuer
Gauge manifold
Low pressure pipe side
High pressure pipe side
Start the refrigeration cycle.
Feed gas from the hose
into the cycle.
Dehumidifier
Refrigeration cycle
Liquid side Gas side
Charging cylinder
for HFC-134a
END
Cautions
(1) The operations described above are intended to ensure the degree of vacuum required for HFC-134a
and to prevent back flow of vacuum pump oil into the cycle.
(2) For these operations use only the special service equipments and jigs for HFC-134a and dehumidifier.
In no case attempt to use the conventional service equipments and jigs (excepting the vacuum pump) for
CFC-12.