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English
I
Pump Down
Pump down means collecting all refrigerant gas in the
system back into the outdoor unit without losing any of
the gas. Pump down is used when the unit is to be
moved or before servicing the refrigerant circuit.
Pump Down Procedure
Be sure to carry out pump down with the unit in
cooling mode.
(1) Connect the Lo side charging hose of the manifold
valve to the service port on the wide tube service
valve.
(2) Using a hex wrench, turn the narrow tube service
valve clockwise all the way to close the service
valve. (Be sure to confirm that the wide tube ser-
vice valve is fully open.)
(3) Press the operation button and start cooling
operation.
(4) When the low pressure gauge reading falls to 1 to
0.5 kg/cm
2
, fully close the wide tube valve stem.
Then quickly stop the unit.
(5) Disconnect all gauges and hoses, and replace the
valve caps as they were before.
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Basic Functions of the Service Valves
The basic functions of the service valves are given in Table 8 below.
Action
Narrow Tube Service
Valve (2-Way)
Wide Tube Service
Valve (3-Way)
CLOSED
Fully OPEN
Fully OPEN
Shipping
Operating and
test running
the air conditioner
Measuring pressure
and gas charging
Air purging with
a vacuum pump
CLOSED
Valve cap
Stem
O-ring
*
*
Table 8
*
The service port on the wide
tube service valve uses a
Schrader core valve to access
the refrigerant system. Therefore,
be sure to use a hose connector
which has a push-pin inside.
(Fig. 60a)
PUSH
Hose with push-pin
Service valve
Fig. 60a
Close
Hex
wrench
Open
Fig. 60b
CAUTION
When opening or clos-
ing the service valve
stem, use the hex
wrench. Be sure to fully
seat the wrench before
turning the valve.
06-154 MCAF186 - 246R5I ENG 3/15/06 11:04 AM Page 22
