Section I. OPERATING PROCEDURES

TM 5-4130-234-13&P

To charge a refrigeration system with refrigerant, the

service unit, is connected to the service unit 115 OUTPUT

service unit CHARGE fitting is loosely connected to the

connection, and leaks are isolated, using the leak detector.

refrigeration system receiver valve with a charge hose, and

d. Evacuation of a Refrigeration System: The

the charge hose is purged with refrigerant and tightened on

refrigeration system suction and receiver valves are

the receiver valve connection. The other fittings in the

opened and the system is purged with dry nitrogen to

fluid system of the service unit are capped and the valves

remove any contaminants. Vacuum hoses are attached to

in the fluid system are closed during this operation. After

the suction and receiver valves and to the EVAC fittings on

connecting the hose between the service unit CHARGE

the service unit. The system is then evacuated to 200

fitting and the refrigeration system receiver valve, the

microns, as monitored on the service unit vacuum gage,

heater surrounding the service unit reservoir is turned on,

for two hours. At the end of two hours evacuation, suction

heating the refrigerant and causing it to expand, increasing

and receiver valves are closed, retaining vacuum in the

the pressure within the reservoir. When the pressure in the

system: then the vacuum pump is shut off and hoses

reservoir has stabilized at approximately 65 psig, the hose

disconnected. It is now necessary to proceed directly to

is purged and tightened at the receiver valve. The

system oil and refrigerant charging operation.

CHARGE valve is opened; then closed. The quantity of

e. Charging Refrigeration System with Oil: The hose

refrigerant contained in the reservoir is noted.

The

assembly, furnished with the service unit, is loosely

receiver valve is opened and the service unit CHARGE

connected to the refrigeration system receiver valve. Air is

valve is controlled to allow the required amount of

purged from the graduated oil fill beaker, using oil used in

refrigerant to enter the refrigeration system, as noted on

the refrigeration system; then the line is tightened on the

the service unit reservoir sight scale. When the proper

receiver valve. The breaker is then filled with enough oil to

amount of refrigerant has entered the refrigeration system,

charge the refrigeration system and have enough oil left

the service unit CHARGE valve is closed; then the receiver

over to prevent air from entering the system. The receiver

valve is closed and the hose is disconnected. The

valve is then closed and the hose assembly disconnected.

refrigeration system is now ready for operation.

f. Charging a Refrigeration System with Refrigerant:

Section I. OPERATING PROCEDURES

2-2.

Preliminary Operating Procedures (See fig. 2-3 and table 2-1.)

2-4