Installation Manual -
A-VMH18D
V
,28T
V
,36Q
V,48PV-1
23
Fig. 9.3
Air Evacuation
9
Safety Precautions
Evacuation 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
High pressure valve
Charge hose
Charge hose
Vacuum pump
Pressure gauge
Low pressure valve
Fig. 9.1
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 off the vacuum pump.
7. Wait for 5 minutes, then check that there has
been no change in system pressure.
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.
Flare nut
Cap
Valve body
Valve stem
Fig. 9.2
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.
CAUTION
system.
•
Use a vacuum pump with a gauge reading
lower than -0.1MPa and an air discharge
capacity above 40L/min.
•
The outdoor unit does not need vacuuming.
DO NOT
open the outdoor unit’s gas and
liquid stop valves.
•
Ensure that the Compound Meter reads
-0.1MPa or below after 2 hours. If after three
hours of operation and the gauge reading is
still above -0.1MPa, check if there is a gas leak
or water inside the pipe. If there is no leakage,
perform another evacuation for 1 or 2 hours.
•
DO NOT
use refrigerant gas to
purge
the
