Vaccuoming
Preparations and Precautions
Air and foreign matter in the refrigerant circuit can
cause abnormal rises in pressure, which can damage
the air conditioner, reduce its efficiency, and cause
injury. Use a vacuum pump and manifold gauge to
evacuate the refrigerant circuit, removing any
non-condensable gas and moisture from the system.
Evacuation should be performed upon initial
installation and when unit is relocated.
BEFORE PERFORMING
Check to make sure the connective pipes
between the indoor and outdoor units
are connected properly .
Check to make sure all wiring is connected
Vaccuoming Instructions
Before using a manifold gauge and a vacuum
pump, read their operation manuals to make
sure you know how to use them properly.
Manifold Gauge
Compound gauge
-76cmHg
Low pressure valve
Charge hose
Low pressure valve
1. Connect the manifold gauge's charge hose
to the service port on the outdoor unit's low
pressure valve.
2. Connect the manifold gauge's charge hose
from the to the vacuum pump.
3. Open the Low Pressure side of the manifold
gauge. Keep the High Pressure side closed.
4. Turn on the vacuum pump to evacuate the system.
5. Run the vacuum for at least 15 minutes, or until
the Compound Meter reads -76cmHG (-1x105Pa).
6. Close the manifold gauge's Low Pressure valve
and turn o the vacuum pump.
7. Wait for 5 minutes, then check that there has
been no change in system pressure.
VACCUOMING
Pressure gauge
High pressure valve
Charge hose
Vacuum pump
NOTE: If there is no change in system pressure,
unscrew the cap from the packed valve (high
pressure valve). If there is a change in system
pressure, there may be a gas leak.
8. Insert hexagonal wrench into the packed valve
(high pressure valve) and open the valve by
turning the wrench 1/4 counterclockwise.
Listen for gas to exit the system, then close the
valve after 5 seconds.
Valve body
Valve stem
9. Watch the Pressure Gauge for one minute to make
sure that there is no change in pressure. It should
read slightly higher than the atmospheric pressure.
10.Remove the charge hose from the service port.
11. Using hexagonal wrench, fully open both the
high pressure and low pressure valves.
OPEN VALVE STEMS GENTLY
When opening valve stems, turn the hexagonal
wrench until it hits against the stopper. DO NOT
try to force the valve to open further.
12.Tighten valve caps by hand, then tighten it
using the proper tool.
13. If the outdoor unit uses all vacuum valves,
and the vacuum position is at the main valve,
the system is not connected with the indoor
unit. The valve must be tightened with a
screw nut. Check for gas leaks before
operation to prevent leakage.
Flare nut
Cap
3