Sinclair ASCU-12A, Service Manual

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U-MATCH AIR CONDITIONERS INSTALLATION
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Vacuum-pumping and leak detection
‹ Dismantle the bonnet of refrigerant valve and air valve.
‹
Align with the center of piping and adequately tighten nuts of connecting pipes by hand
‹ Tighten the nuts with a spanner.
‹ Remove the one way valve cap of air valve.
‹ Unscrew the spool of refrigerant valve for 1/4 turn with a socket head wrench, and at the
same time push up the spool of air valve with a screwdriver to let air give off.
‹ Air exhaust continues for 15 seconds until coolant gas appears, immediately shut off one way
valve and tighten the valve cap.
‹ Totally open the spool of refrigerant valve and air value (as shown in Figure 3-1-4)
Figure 3-1-4
‹ Tighten the valve caps and use soapy water or a leak detector to check any leakage on indoor
unit, outdoor unit and connection parts of pipes.
Caution
：
If conditions are allowed, a vacuum pump shall be used for drawing off air inside the system at a
valve. Method for creation of vacuum by using a vacuum pump is as follows:
‹ Take out the nut cover of the inlet for refrigerant.
‹ Connect the tube of the vacuum watch with the vacuum pump, having the low-pressure end
linking to the inlet for refrigerant. (As shown in Figure 3-1-5)