Sanyo 12KS71 Installation Instructions - Page 22

Pump Down, Basic Functions of the Service Valves

Page 22 highlights

05-424 KS0971-1271 12/13/05 1:28 PM Page 22 s Basic Functions of the Service Valves The basic functions of the service valves are given in Table 8 below. Table 8 Action Shipping Narrow Tube Service Valve (2-Way) CLOSED Wide Tube Service Valve (3-Way) O-ring Valve cap Stem Operating and test running the air conditioner Fully OPEN Fully OPEN Measuring pressure * and gas charging Air purging with a vacuum pump CLOSED CAUTION When opening or clos- ing the service valve Open stem, use the accessory hex wrench. Be sure to fully seat the wrench before turning the valve. Close Hex wrench Fig. 60b * Hose with push-pin * 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) Service valve PUSH Fig. 60a s 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 service valve is fully open.) (3) Press the operation button and start cooling operation. (4) When the low pressure gauge reading falls to 14.2 to 7.1 psi (1 to 0.5 kg/cm2), 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. 22

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24

22
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 service
valve is fully open.)
(3)
Press the operation button and start cooling oper-
ation.
(4)
When the low pressure gauge reading falls to 14.2 to
7.1 psi (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.
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 ser-
vice valve uses a Schrader core valve
to access the refrigerant system.
Therefore, be sure to use a hose con-
nector 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 accessory
hex wrench. Be sure to
fully seat the wrench
before turning the valve.
05-424 KS0971-1271
12/13/05
1:28 PM
Page 22