System Evacuating-Charging Information
6. EVACUATING-CHARGING THE SYSTEMCAUTION: An AC system that is excessively low on refrigerant or has been open for any length of time must be evacuated and recharged. This is necessary to remove any air and/or moisture that may have entered the system. Trapped air will cause system malfunctions. Moisture will combine with R12 Freon to form harmful acids or it may collect and freeze in the expansion valve orifice blocking refrigerant flow.
FIGURE 17:
Discharging The System
WARNING: Wear protective goggles when servicing the system.
1. Connect pressure gauge and manifold assembly J-23575 (Fig. 17) to the compressor service valves.
2. Insert center service fitting hose or manifold assembly into service bay exhaust system.
3. Mid-position service valves on Alliance models.
4. Open both manifold valves slightly and allow refrigerant to discharge SLOWLY from system.
CAUTION: Do not discharge the system rapidly. The compressor oil will be forced out along with the refrigerant.
Evacuating Procedure with J-26695 Vacuum Pump
The J-26695 Vacuum Pump and motor is a self-contained unit with a carrying handle and stand. The unit must be kept upright at all times to prevent oil from spilling.
1. Connect pressure gauge and manifold assembly J-23575 to the compressor service valves and discharge the system.
2. Connect center service fitting hose to the inlet fitting on the vacuum pump.
3. Open both manifold hand valves completely.
4. Start the vacuum pump. Note the compound gauge reading.
5. Operate the pump a MINIMUM OF 30 MINUTES after reaching lowest vacuum indicated on the gauge.
6. Test the system for leaks. Close both manifold hand valves, turn off the vacuum pump, and note the compound gauge reading. The gauge needle should remain stationary at the point at which the pump was turned off.
^ If the gauge needle returns to zero rapidly, install a partial charge in the system and locate the leak with a leak detector. Repair the leak and evacuate the system again.
^ If the gauge needle remains stationary and vacuum is maintained for three to five minutes, resume evacuation for MINIMUM OF 30 MINUTES.
7. Close both manifold hand valves and turn off the vacuum pump.
8. Disconnect the center service fitting hose from the vacuum pump. System is now ready for charging.
FIGURE 18:
Evacuation Procedure with J-23500-01 Portable Air Conditioning Service Station
The J-23500-01 Portable Air Conditioning Service Station is equipped with a vacuum pump, meteringcharging cylinder, refrigerant supply, gauges, hoses and hand control valves (Fig. 18).
The control switch for the vacuum pump is mounted on the front of the charging station. It should be in the OFF position before inserting the plug into a power source.
NOTE: The system must be completely de-pressurized before evacuating. With the system under pressure, refrigerant may enter and damage the vacuum pump.
1. Close all hand valves on the station.
2. Connect the red charging hose to the compressor discharge service valve port.
3. Connect the blue charging hose to the compressor suction service valve port.
4. Discharge the system. On Alliance models only, mid-position the suction and discharge service valves.
5. Connect the vacuum pump hose to the vacuum pump inlet.
6. Open the low and high pressure hand control valves control on the charging station.
7. Start the vacuum pump and open the vacuum control valve. Note compound gauge reading.
8. Operate the pump MINIMUM OF 30 MINUTES after reaching lowest vacuum indicated on compound gauge.
9. Fill the charging cylinder, as described below, while the system is evacuating.
10. Close the vacuum control valve and stop the vacuum pump. Observe blue compound gauge to determine if leak exists. If leak does not exist, system is now ready for changing.
Filling the Charging Cylinder
1. Be certain the refrigerant drum is inverted and the valve is open.
2. Open the right hand valve at the base of the charging cylinder and fill with enough refrigerant to charge the system. Liquid refrigerant will be observed rising in the charging cylinder sight glass.
3. Crack open the valve at the top of the cylinder when pressure in the charging cylinder equals pressure in the supply tank. This relieves head pressure and allows refrigerant to continue filling the cylinder.
4. Observe the pressure gauge at the top of the cylinder and rotate the plastic shroud until the pressure heading column corresponds with the gauge pressure in line with the sight glass.
NOTE: For example, if the pressure gauge at the top of the cylinder reads 70 PSI, find the column with the pressure heading of "70" and rotate the shroud so the "70" column aligns with the sight glass.
5. When refrigerant reaches the desired level in the sight glass, close both the right hand valve at the base of the cylinder and the refrigerant drum valve. Be certain the top cylinder valve is fully closed.
NOTE: If bubbling occurs in the sight glass, tilt the charge station back momentarily.
6. Connect heating element cord to heating element receptacle of power pack and turn heater switch ON. Allow refrigerant to heat (building up pressure proportionately) for about ten minutes while vacuum pump is running.
Charging the System
Check and adjust the compressor oil level before charging.
Charging Procedure with Multi-Refrigerant Can Tool J-6272-02
The following charging procedure is based on the use of pressure gauge and Manifold Assembly J-23575, and Multi-Refrigerant Can Tool J-6272-02.
WARNING: Wear protective goggles when servicing the system.
1. Connect pressure gauge and Manifold Assembly J-23575 and evacuate the system. Keep both service valves in mid-position on Alliance models.
2. Close both manifold hand valves.
3. Disconnect service hose from vacuum pump and connect it to center of Multi-Refrigerant Can Tool J-6272-02. Close four petcock valves on tool dispenser.
4. Attach necessary number of refrigerant cans.
5. Open one petcock valve. Loosen center service hose at pressure gauge and manifold assembly allowing refrigerant to purge air from line. Tighten service hose connection and close petcock valve.
6. Open suction (compound) gauge hand valve and one petcock valve. Do not open discharge (high pressure) gauge hand valve.
WARNING: Use extreme caution when the engine is operating. Do not stand in direct line with the fan. Do not put hands near pulleys, belts or fan. Do not wear loose clothing.
7. Start the engine and place air conditioning controls in maximum cooling position. The compressor will operate and help pull refrigerant into the suction side of the system.
NOTE: The refrigerant cans may be placed upright in warmwater NO HOTTER THAN 125~F to speed up the charging process.
8. When first refrigerant can is empty, open another and continue charging system.
9. Continue charging until required amount of refrigerant is in the system. Frost line on refrigerant can will indicate how much refrigerant has entered system. This may be used as a guide when a system requires a fraction of a full can.
NOTE: If an accurate scale is available, weigh the refrigerant cans before and during the charging procedure to be sure the correct amount of refrigerant is being used.
10. When system is fully charged, close suction (compound) gauge hand valve and all petcock valves.
11. Operate system five to ten minutes to allow it to normalize and to determine if system cycles properly.
Charging Procedure with Portable Air Conditioner Service Station J-23500-01
WARNING: Wear protective goggles when servicing the system.
1. Fill the cylinder. Refer to Filling Charging Cylinder.
2. Discharge and evacuate system.
3. Close low pressure valve on charging station. Fully open left hand refrigerant control valve at base of cylinder and high pressure valve on charging station. Allow required charge of refrigerant to enter high side of system. Close refrigerant control valve and high pressure valve on charging station when system is charged.
CAUTION: Do not permit liquid level to drop below zero on cylinder sight glass.
4. Close manifold gauges after completion of charging, and check high and low pressures and system operation.
CAUTION: READ GAUGES WITH HIGH AND LOW PRESSURE VALVES ON CHARGING STATION CLOSED. THE LOW PRESSURE GAUGE COULD BE DAMAGED IF BOTH HIGH AND LOW PRESSURE VALVES OF MANIFOLD ARE OPENED. HIGH PRESSURE DEVELOPED IN DISCHARGE SIDE (HIGH SIDE) OF COMPRESSOR WOULD DAMAGE THE GAUGE.
5. Close all valves on charging station and close refrigerant drum valve when all operations are completed.
6. On Alliance models, after completing operational checks, back-seat the suction and discharge service valves to their normal operating position by turning them fully counterclockwise.
7. Disconnect the high and low pressure charging hoses from compressor with care. (A small amount of refrigerant remaining in the hoses will escape.) Place the charging hoses on hose back on the charging station to keep air and dirt out of them.
8. Open the valve at the top of the station charging cylinder to remove any remaining refrigerant.
NOTE: The charging cylinder is not designed to store refrigerant
9. Install caps on Alliance compressor service valves when service is completed.
FILING INSTRUCTIONS
File this I.S. Note in your M.R. 171 binder.