Air Purging - Kelvinator KSE88HRB Installation Manual

Air purging

Air purging
Air and moisture remaining in the refrigerant system have
undesirable effects as indicated below.
• Pressure in the system rises.
• Operating current rises.
• Cooling (or heating if applicable) efficiency drops.
• Moisture in the refrigerant circuit may freeze and block
capillary tubing.
• Water may lead to corrosion of parts in the refrigeration
system.
Therefore, the indoor unit and tubing between the indoor
and outdoor unit must be leak tested and evacuated to
remove any noncondensables and moisture from the system.
Air purging with vacuum pump
A Preparation
• Check that each tube (both liquid and gas side tubes)
between the indoor and outdoor units have been
properly connected and all wiring for the test run has
been completed. Remove the service valve caps from
both the gas and the liquid side on the outdoor unit.
Note that both the liquid and the gas side service valves
on the outdoor unit are kept closed at this stage.
• Pipe length and refrigerant amount:
Connecting Air purging Additional amount of
pipe length method refrigerant to be charged
Use vacuum
Less than 5m
—
pump
(2.6-5.3kW) Models:
Use vacuum (Pipe length-5) x 20g/m
More than 5m
pump (6.2-8.8kW) Models:
(Pipe length-5) x 40g/m
B Leak test
• Connect the manifold set (with pressure gauges) and dry
nitrogen gas cylinder to this service port with
charge hoses.
caution
Be sure to use a manifold set for air purging. If it is not
available, use a stop valve for this purpose. The "Hi" knob
of the manifold valve must always be kept closed.
• Pressurise the system to no more than 1MPa (approx.
145psi) with dry nitrogen gas and close the cylinder
valve when the gauge reading reaches 1MPa
(approx.145psi). Next, test for leaks with liquid soap.
caution
To avoid nitrogen entering the refrigerant system in a
liquid state, the top of the cylinder must be higher than its
bottom then you pressurise the system.
Usually, the cylinder is used in a vertical standing position.
• Do a leak test of all joints of the tubing (both indoor
and outdoor) and both gas and liquid side service
valves.
16 air purging Kelvinator Air Conditioning
• Bubbles indicate a leak. Be sure to wipe off the soap
with a clean cloth. After the system is found to be free
of leaks, relieve the nitrogen pressure by loosening the
charge hose connector at the nitrogen cylinder. When
the system pressure is reduced to normal, disconnect the
hose from the cylinder.
Lo Hi
Charge hose
Gas leak check
1 Apply soapy water or a neutral liquid detergent on the
indoor or outdoor unit connections using a soft brush to
check for leakage of the connecting points of the piping.
2 If bubbles come out, the pipes are leaking.
Note: A Lo stop valve
B Hi stop valve
C and D: connections to the indoor unit.
C Evacuation
• Connect the charge hose end described in the
preceding steps to the vacuum pump to evacuate
the tubing and indoor unit.
Confirm the "LO" control knob of the manifold set
is open. Then run the vacuum pump. The operation
time for evacuation varies with tubing length and
capacity of the pump. The following table is a guide
for evacuation times.
Air Purge Time required
Pipe Length (L)
Method (min)
<5m
Use vacuum pump 25
5~10m
Use vacuum pump 30
• When the desired vacuum is reached, close the "LO"
knob of the manifold set and stop the vacuum pump.
D Finishing the job
• With a service valve wrench, turn the valve stem of liquid
side valve counter-clockwise to fully open the valve.
• Turn the valve stem of gas side valve counter-clockwise
to fully open the valve.
• Loosen the charge hose connected to the gas side
service port slightly to release the pressure, then remove
the hose.
• Replace the valve cap on the gas side service port and
fasten the cap securely.
• This process is very important to prevent leakage from
the system.
• Replace the valve caps at both gas and liquid side
service valves and fasten them tightly.
• This completes air purging with a vacuum pump.
The air conditioner is now ready to test run.
Indoor unit
Outdoor unit
Manifold set
Pressure
gauge
Lo Hi
Open
Close
Vacuum pump
Kelvinator Air Conditioning air purging 17