20
Cap tightening torque:
170 – 215 lbs·in
(200 – 250 kgf·cm)
(Tighten by hand, then
use a wrench to turn
approximately
45°.)
Stopper
Spindle
Service port
Screw diameter: 1/2
UNF 20 threads
Valve core
Cap nut tightening torque:
60 – 95 lbs·in
(70 – 110 kgf·cm)
(Tighten by hand, then use a
wrench to turn approximately 30 .)
<Structure of service valve on wide tube side>
External diameter of service port
R410A: 5/16"
NOTE
Fig. 21
When using a hex wrench to open the spindle, an
extremely small amount of refrigerant may leak.
This does not indicate a problem.
Use a hex wrench of a type to which force can be
easily applied.
(4) With the “Lo” knob of the manifold valve open and high-pressure valve (“Hi”) closed completely, run the vacuum pump.
Run the pump until the pressure is –101 kPa (–76 cmHg). The operation time for the vacuum pump varies with tubing
length and the capacity of the pump. The following table shows the amount of time required for evacuation:
Table 5
(5) With the vacuum pump still running, close the “Lo” knob of the manifold valve. Then stop the vacuum pump. Fully
close the low-pressure valve and stop the vacuum pump. (Wait 1 – 2 minutes and check that the manifold gauge
pointer does not return. If it does return, find and repair the leak, then apply the vacuum again.)
(6) With a hex wrench, turn the valve stem on the narrow tube service valve counter-clockwise by 90 degrees (1/4 turn)
for 10 seconds, and then turn the stem clockwise to close it again.
(7) With a standard screwdriver, turn the wide tube service valve stem counterclockwise to fully open the valve.
(8) Turn the narrow tube service valve stem counter-clockwise to fully open the valve.
(9) Loosen the vacuum hose connected to the wide tube service port slightly to release the pressure. Then, remove
the hose.
(10) Leak test all joints at the tubing (both indoor and outdoors) with liquid soap. Bubbles indicate a leak. Be sure to wipe
off the soap with a clean cloth.
CAUTION Be sure to completely insert the hex
wrench before attempting to turn the
valve.
Required time for evacuation when capacity
of 100 liter/h vacuum pump is used
20 min. or more
The required time in Table 5 is calculated based on the
assumption that the ideal (or target) vacuum condition is
around 10 mmHg abs.
NOTE
CAUTION If a CFC gas detector is used, use a
special detector for HFC refrigerant
(such as R410A and R134a).
Perform the air purge for tubes A, B, C, and D. Use the same
procedures for all tubes.
(1) Check that each tube (both narrow and wide tubes)
between the indoor and outdoor units have been proper-
ly connected and all wiring for the test run has been
completed. Note that both narrow and wide tube service
valves on the outdoor unit are kept closed at this stage.
(2) Using an adjustable wrench or box wrench, remove the
valve caps from the service valve on both narrow and
wide tubes.
(3) Connect a vacuum pump and a manifold valve (with
pressure gauges) to the service port on the wide tube
service valve. (Fig. 20).
CAUTION Be sure to use a manifold valve 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.
CAUTION Before using the vacuum pump
adapter, read the vacuum pump
adapter manual, and use the
adapter correctly.