Installation Manual

Vacuum Procedure

Important: Use a quality Micron Gauge to measure and validate the proper system vacuum

level achieved. Do not rely on the scale of a“bourbon tube”type gauge set to validate the

depth and quality of the vacuum.

1. Remove the caps of the liquid valve, gas valve and service port.

2. Connect gauge manifold and micron gauge to the service ports provided at the liquid and

suction service valves.

3. Connect a vacuum pump to the manifold gauge.

4. Open the lower pressure side of the manifold valve assembly and start the vacuum pump.

The switch at the high pressure side of the manifold valve assembly should be kept closed,

or evacuation does not fail.

5. Operate vacuum pump until a vacuum of 500 microns or less is achieved. The evacuation

duration depends on the vacuum pump size and unit’s capacity, generally 20 minutes for

the 9,000 BtuH units, to 1 hour for a larger 36,000 BtuH unit.

6. Close the manifold valves and shut off the pump.

a. If vacuum holds below 700 microns for 15

minutes, the system can be considered dry

and leak free. Go to step 5.

b. If vacuum increases to 800 microns or greater,

this is an indication of moisture in system

or a leak exists. Identify leak and repair as

necessary, after which repeat steps 4 and 5.

If moisture is suspect, purge system use triple

evacuation method using dry nitrogen.

7. Confirm that manifold valves are closed and disconnect the vacuum pump.

8. Open the service valves to the fully ‘back-seat’ position to let the refrigerant flow to the

indoor unit and balance the pressure in system.

Note: Do not allow air to enter the connection pipe when removing the hose.

9. Replace service valve caps and tighten.

TESTING AND INSPECTION

Service port