Evacuating System - Piper PA-32R-301 SARATOGA SP Maintenance Manual

COOLING (cont.)
K. Discharging System (cont.)
Applies to Kent Moore J23500 or similar charging station.
(Refer to Figure 8.)
(a) Close all valves on charging station.
(b) Connect red high pressure charging line to high pressure Schrader valve at the evaporator fitting.
(c) Open high pressure control valve on charging station one turn.
(d) Hold end of blue low pressure charging line in a shop rag and slowly open low pressure control
valve on charging station allowing refrigerant to exhaust from system into shop rag.
L. Evacuating System
Compound Gauge
Pull 26 to 28
inches Vacuum
Vacuum Pump
OUT
Anytime the system has been operated in a discharged condition, or the system has been open to
atmospheric pressure, the receiver-dehydrator must be replaced and the system evacuated to remove
any trapped air and moisture. Use a vacuum pump capable of pulling 29 inches of mercury or better.
As the pressure in the air conditioning system is lowered the boiling temperature of any water (mois-
ture) in the system is lowered. The water can then be pulled out of the system in the form of vapor,.
Chart 4 demonstrates the effectiveness of moisture removal under a given vacuum.
PIPER AIRCRAFT
PA-32R-301/301T
MAINTENANCE MANUAL
Pressure Gauge
OPEN
L
OPEN
Manifold
Gauge Set
Evacuation Hookup
— NOTE—
H
H
Manifold Assembly
Figure 7
1I8
Service Valve
Service Valve
L
Reissued: July 1, 1993
21-50-00
Page 21-25