Sanyo CMH1972 Technical & Service Manual page 85

(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 pres-
sure 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
Required time for evacuation when capacity
of 100 liter/h vacuum pump is used
20 min. or more
NOTE
The required time in the above table is calculated
based on the assumption that the ideal (or target) vac-
uum condition is around 10 mmHg abs.
(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 nar-
row tube service valve counter-clockwise by 90
degrees (1/4 turn) for 10 seconds, and then turn
the stem clockwise to close it again.
Be sure to completely insert
CAUTION
the hex wrench before
attempting to turn the valve.
(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.
If a CFC gas detector is used,
CAUTION
use a special detector for HFC
refrigerant (such as R410 and
R134a).
17