VACUUM TESTING
Step 9
Leaking Test
1. Connect the charging hose of the manifold valve to charge the end of the low-pressure valve.
2. Add dry nitrogen to a pressure of 200 lbs. Tightly close both high- and low-pressure valves.
3. Leak-test flare fittings with soap bubbles. If no leak is detected, release nitrogen.
Step 10
System Vacuum and Charge
UNIT DAMAGE HAZARD
Never use the system compressor as a vacuum pump. It may result in equipment damage
or improper system operation.
Refrigerant pipes and indoor coil should be evacuated using the recommended deep vacuum
method of 500 microns. The alternate triple evacuation method may be used if the procedure
outlined below is followed.
NOTE:
Alway break a vacuum with dry nitrogen.
Using Vacuum Pump
1. Completely tighten flare nuts A, B, C, D,
connect manifold gage charge hose to a
charge port of the low side service valve.
2. Connect charge hose to vacuum pump.
3. Fully open the low side of manifold gage.
See figure at right.
4. Start vacuum pump.
CAUTION
Manifold Gauge
19
Outdoor Unit
Service Valve
500 microns
Low Side Valve
High Side Valve
Charge Hose
Vacuum Pump
Low Side Valve
Charge Hose
Refrigerant
Indoor Unit
Low Side
High Side
