(4)With the “Lo” knob of the manifold valve open, run the vacuum pump. The operation time for the vacu- um pump varies with tubing length and the capacity of the pump. The following table shows the amount of time for evacuation:
Table 6
Required time for evacuation when
26.4 gal/h (100 liter/h) vacuum pump is used
If tubing length is | If tubing length is |
less than 33 ft. (10 m) | more than 33 ft. (10 m) |
|
|
10 min. or more | 15 min. or more |
|
|
NOTE
To prevent other refrigerants from being mistakenly charged to units which use R410A, the size of the charge port on the service valve is different from the one for other refrigerant types. For servicing such as recharging, the specified charging hose, manifold and vacuum pump adapter (with reverse flow prevention) for R410A must be used.
NOTE
(5) With the vacuum pump still running, close the “Lo” | The required time in Table 6 is calculated based on the |
knob of the manifold valve. Then stop the vacuum | assumption that the ideal (or target) vacuum condition |
pump. | is around 0.193 psi (10 mmHg abs.). |
(6) With the hex wrench, turn the valve stem on the |
| |
narrow tube service valve | 90° (1/4 turn) | |
90 degrees (1/4 turn) for 10 seconds, and then turn | Narrow tube | |
| ||
the stem clockwise to close it again. (Fig. 28) | Hex wrench | |
|
| |
CAUTION | Be sure to completely insert the hex | Wide tube |
|
| |
wrench before attempting to turn the valve.
(7) Leak test all joints at the tubing (both indoor and outdoors) with |
| |
soapy water. Bubbles indicate a leak. Tighten the joint more |
| |
when leaks, then check if there is no leak. Be sure to wipe off the | Valve cap | |
soap with a clean cloth. | Vacuum hose to manifold valve | |
Fig. 28 | ||
|
(8)With the hex wrench, turn the wide tube service valve stem
(9)Turn the narrow tube service valve stem
(10)Loosen the vacuum hose connected to the wide tube service port slightly to release the pressure. Then, remove the hose.
CAUTION
This may cause the refrigerant gas to leak. In order to avoid this, take off the hose quickly.
(11)Fasten the valve cap on the wide tube service port securely with an adjustable wrench or box wrench. Next, mount the valve cap on the service valve and tighten it to 170 lbs·in (200 kgf·cm) with a torque wrench. This process is very important to prevent gas from leaking from the system.
(12)Test run the air conditioner. (See next page.)
(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 condi- tioner is ready for actual operation.
24
