5-6. Taping the Tubes
(1)At this time, the 2 refrigerant tubes (and electrical wire if local codes permit) should be taped together with armoring tape. The drain hose may also be included and taped together as 1 bundle with the tubing.
(2)Wrap the armoring tape from the bottom of the outdoor unit to the top of the tubing where it enters the wall. As you wrap the tubing, overlap half of each previous tape turn. (Fig. 25)
(3)Clamp the tubing bundle to wall, using 1 clamp approx. every 47" (120 cm).
NOTE
Do not wind the armoring tape too tightly, since this will decrease the heat insulation effect. Also, be sure the con- densation drain hose splits away from the bundle and drips clear of the unit and the tubing.
5-7. Finishing the Installation
After finishing insulating and taping over the tubing, use sealing putty to seal off the hole in the wall to prevent rain and draft from entering. (Fig. 26)
6. Air Purging
Air and moisture remaining in the refrigerant system have undesirable effects as indicated below. Therefore, they must be purged completely.
pressure in the system rises
operating current rises
cooling (or heating) efficiency drops
moisture in the air may freeze and block capillary tubing
water may lead to corrosion of parts in the refrigerant system
Air Purging with a Vacuum Pump (for Test Run)
(1)Check that each tube (both narrow and wide tubes) between the indoor and outdoor units have been proper- ly connected and all wiring for the test run has been completed. Note that both narrow and wide tube service valves on the outdoor unit are kept closed at this stage.
(2)Using an adjustable wrench or box wrench, remove the valve caps from the service valve on both narrow and wide tubes.
(3)Connect a vacuum pump and a manifold valve (with pressure gauges) to the service port on the wide tube service valve. (Fig. 27)
| Clamp |
Insulated tubes | Drain hose |
Apply putty here
Fig. 25
Tubing
Fig. 26
Indoor unit
Outdoor unit
Manifold valve 
(Exclusively for R410A)
Pressure | Lo | Hi |
gauge |
|
|
CAUTION
CAUTION
The service port on the wide tube service valve uses a Schrader core valve to access the refrigerant system. The valve core is similar to those used in automobile tires. Therefore, be sure to use a vacuum hose connector which has a
Be sure to use a manifold valve for air purging. If it is not available, use a stop valve (field supply) for this purpose. The “Hi” knob of the manifold valve must always be kept closed.
Charging hose (Exclusively for R410A)
Vacuum pump adapter (Exclusively for R410A)
(with reverse flow prevention)
Vacuum pump
Fig. 27
23
