Sanyo CM1972 - Manual (Page 82)

20
■ Pump Down
● When relocating or disposing of the A/C, request this service from
the dealer where the unit was purchased, or from an appropriate
agent. Perform pump-down as described below.
What is pump-down?
● Pump-down refers to recovering the refrigerant gas from the refrig-
erant cycle at the outdoor unit. This work must be performed dur-
ing cooling operation. The refrigerant gas cannot be recovered
during heating operation.
● During winter, or if the temperature sensor prevents cooling opera-
tion, perform “forced cooling operation.”
Pump-down procedure
(1) Fully close the spindles at the valves on the narrow tube side of
tubes A, B, C and D. (Refer to Fig. 22.)
(2) Connect the manifold gauge to the charging port at the valve on
the wide tube side of tube D. Purge the air from the charging hose.
(Refer to Fig. 23.)
(3) Perform cooling operation or forced cooling
operation.
When the pressure at the low-pressure side is 0.15 – 0.2 MPa
(0.5 – 1 kg/cm 2 G), fully close the spindles at the valves on the
wide tube side of tubes A, B, C, and D, and immediately stop
operation. (Refer to Fig. 23.)
In the winter, the outdoor unit may stop after 5 - 10 minutes of
operation. This is in order to protect the indoor unit heat
exchanger from freezing and does not indicate a problem.
(4) Disconnect the manifold gauge and the inter-unit tubes, and
attach the caps and flare nuts. At this point, pump-down is com-
pleted. (If the caps and flare nuts are not reattached, there is the
danger of gas leakage.) (Refer to Fig. 24.)
If pump-down is not possible
If the A/C cannot be operated because of a malfunction or other
cause, use a refrigerant recovery device to recover the refrigerant.
In order to protect the earth’s environment, be sure to perform pump-down to recover refrigerant
gas without releasing it into the atmosphere.
Fig. 22
(11) Replace the flare nut on the wide tube service port and fasten the flare nut securely with an adjustable wrench or
box wrench. Next, mount the valve cap and tighten it with a torque wrench (the cap needs to be tightened with the
torque of 180 lbs·in (200 kgf·cm)). This process is very important to prevent gas from leaking from the system.
(12) Test run the air conditioner. (See page 25.)
(13) While the air conditioner is running, apply liquid soap to check for any gas leaks around the service valves or caps.
(14) If there is no leakage, stop the air conditioner.
(15) Wipe off the soap on the tubing.
This completes air purging with a vacuum pump and the air conditioner is ready for actual operation.
Fig. 23
C
D
B
A
Manifold gauge
Wide tube side
Cap
Cap
Cap
Cap
After disconnecting
the inter-unit tubes,
attach the flare nuts
with flare bonnets.
Fig. 24
D
C
B
A
Charging port
Narrow tube side
Close
Close
Close
Close
07-156 CM-CLM1972-3172 6/6/07 9:35 AM Page 20