11
English
7-8 Air tight test and vacuum drying
After doing the piping, perform the following inspections.
Be sure to use nitrogen gas. (See the figure (“Shutoff valve operation
procedure”) for the location of the service port.)
[Procedure]
Pressurize from the liquid pipes and gas pipes to 550PSI (and not above
550PSI). If there is not pressure drop over the next 24 hours, the equip-
ment has passed the test.
If the pressure drops, check for leakage positions. (Confirm that there is
no leakage, then release nitrogen.)
Use a vacuum pump that can create a vacuum down to at least
–
14.6PSI
.
[Procedure]
Operate the vacuum pump for
at least 2 hours
from
both the liquid
and gas pipes
and decrease the pressure to at least –14.6PSI.
Leave at below –14.6PSI for at least 1 hour and make sure that the vac-
uum gauge does not rise. (If it does rise, there is either still moisture in
the system or a leak.)
Cases where moisture might enter the piping
(i.e., if doing work dur-
ing the rainy season, if the actual work takes long enough that conden-
sation may form on the inside of the pipes, if rain might enter the pipes
during work, etc.)
After performing the vacuum drying for 2 hours, pressurize to 7.2PSI
(i.e., vacuum breakdown) with nitrogen gas, then depressurize down to
at least –14.6PSI a for an hour using the vacuum pump (vacuum dry-
ing). (If the pressure does not reach at least –14.6PSI even after
depressurizing for at least 2 hours, repeat the vacuum breakdown - vac-
uum drying process.) Leave as a vacuum for 1 hour after that, and make
sure the vacuum gauge does not rise.
(Refer to figure 28)
1.
Decompression valve
2.
Nitrogen
3.
Vacuum pump
4.
Valve (Open)
5.
Charge hose
6.
Shutoff valve service port
7.
Indoor unit
8.
Gas line shutoff valve (Close)
9.
Liquid line shutoff valve (Close)
10.
Indicates local procurement
11.
Outdoor unit
NOTE
The shutoff valve must always be turned to “closed”.
Otherwise the refrigerant in the outdoor unit will pour out.
• The names of parts needed to operate the shutoff valve are shown in
the figure below. The unit is shipped from the factory with the shutoff
valve turned to the “closed” position.
• Since the side boards may be deformed if only a torque wrench is
used when loosening or tightening flare nuts, always lock the shutoff
valve with a wrench and then use a torque wrench.
• In cases where the unit is run in heating mode when the outside tem-
perature is low or in other situations where the operating pressure
might drop, seal the gas-side flare nut on the shutoff valve with sili-
con sealant or the like to prevent it from freezing.
Shutoff valve operation procedure
Have a hex wrench ready (size: 0.2in. and 0.3in.).
Opening the valve
1.
Place the hex wrench on the valve bar and turn counter-clockwise.
2.
Stop when the valve bar no longer turns. It is now open.
Close the valve
1.
Place the hex wrench on the valve bar and turn clockwise.
2.
Stop when the valve bar no longer turns. It is now closed.
• A seal is attached to the point indicated by the arrow.
Take care not to damage it.
• Be sure to tighten the valve lid securely after operating the valves.
• Use a push-rod-provided charging hose for operation.
• Be sure to tighten the valve lid securely after operation.
Tightening torque ................. 8.5 ~ 10.3 ft·lbf
Air tight test
Vacuum drying
Shutoff valve operation procedure
Precautions when handling the shutoff valve
Servicing port
Valve bar
Valve lid
Interunit piping connection
Precautions for handling valve lid
Liquid-side tightening torque
Gas-side tightening torque
10.0 ~ 12.2 ft·lbf
16.6 ~ 20.3 ft·lbf
Precautions for handling servicing port
Silicon sealing pad
(Make sure that there is no gap)
Direction to open
Direction to open
<Gas pipe>
<Liquid pipe>
Valve lid
Shutoff valve
(lid attachment)
01_EN_3PN07193-6F.fm Page 11 Tuesday, September 1, 2009 4:13 PM
