Carrier 40QSM009DS Service Manual page 71

3/4" (19) 990~1210 9270~11860
13.4.3 First-Time Installation
Air and moisture in the refrigerant system
cause the following problems:
● Increases in system pressure
● Increases in operating current
● Decreases in cooling and heating efficiency
● Blocks in capillary tubing caused by
moisture in the refrigerant circuit freezing
● Corrosion of parts in the refrigerant system
caused by water
The indoor units and the pipes between
indoor and outdoor units must be tested for
leakages and evacuated to remove gas and
moisture from the system.
Gas leak check with soap water:
Apply soap water or a liquid neutral
detergent on the connections with a soft brush
to check for leakage in the pipe connecting
points. If bubbles emerge, the pipes are
leaking.
1. Air Purging Using the Vacuum Pump
1) Completely tighten the flare nuts on the
indoor and outdoor units. Confirm that both
the2-way and 3-way valves are set to the
closed position.
2) Connect the charge hose with the push pin
of the Handle Lo to the 3-way valve gas
service port.
3) Connect the charge hose of the Handle Hi
to the vacuum pump.
4) Fully open the Handle Lo of the manifold
valve.
5) Turn on the vacuum pump to begin
evacuation.
6) Conduct a 30-minute evacuation. Check
whether the compound meter indicates
-0.1Mpa(14.5Psi). If the meter does not
indicate -0.1Mpa(14.5Psi) after 30 minutes
has elapsed, continue evacuation for 20
more minutes. If the pressure does not
reach -0.1Mpa(14.5Psi) after 50 minutes
has elapsed, check if there are any leaks.
Fully close the Handle Lo valve of the manifold
valve and turn off the vacuum pump. After 5
minutes, confirm that the gauge needle is not
moving.
7) Turn the flare nut on the 3-way valve45°
counterclockwise for 6-7 seconds. Once
gas begins to come out, tighten the flare nut.
Make sure the pressure display on the
pressure
atmospheric pressure. Then remove the
charge hose from the 3-way valve.
8) Fully open the 2-wayand 3-way valves and
securely tighten the cap on the 3-way valve.
2. Air Purging Using Refrigerant
Procedure:
1). Confirm that both the 2-way and 3-way
valves are set to the closed position.
2). Connect the charge set and a charging
cylinder to the service port on the 3-way valve.
3). Air purging:
Open the valves on the charging cylinder and
the charge set. Loosen the flare nut on the
2-way valve approximately 45° for 3 seconds
then closing it for 1 minute. Repeat 3 times.
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