STEP 4 −− LEAK TEST AND EVACUATION (Continued)
EVACUATION
3CONNECT GAUGE SET
NOTE
LOW HIGH
A.Connect low side of manifold gauge set with 1/4 SAE in−line tee to vapor line service valve
B.Connect high side of manifold gauge set to liquid line service valve
C.Connect available micron gauge connector on the 1/4 SAE in−line tee.
D.Connect the vacuum pump (with vacuum gauge) to the center port of the manifold gauge set. The center port line will be used later for both the HFC−410A and nitrogen containers.
NITROGEN
NOTE − Position canister to deliver liquid refrigerant.
HFC−410A
OUTDOOR
UNIT
A
B |
1/4 SAE TEE WITH SWIVEL COUPLER
500
C
MICRON
GAUGE
MANIFOLD
GAUGE SET
TO VAPOR
SERVICE VALVE
VACUUM PUMP
TO LIQUID LINE
SERVICE VALVE
D
4 EVACUATE THE SYSTEM
RECOMMEND
MINIMUM 3/8" HOSE
A.Open both manifold valves and start the vacuum pump.
B.Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).
NOTE | ure indicates a |
relatively large leak. If this occurs, repeat the leak testing procedure. | |
NOTE | absolute pressure means the total actual pressure above zero within a given volume or system. Absolute pressure in a |
vacuum is equal to atmospheric pressure minus vacuum pressure.
C.When the absolute pressure reaches 23,000 microns (29.01 inches of mercury),
perform the following: | WARNING ! | |
S Close manifold gauge valves. | ||
| ||
S Close valve on vacuum pump. | Possible equipment damage. | |
| ||
S Turn off vacuum pump. | Avoid deep vacuum operation. Do not use | |
S Disconnect manifold gauge center port hose from vacuum pump. | compressors to evacuate a system. | |
S Attach manifold center port hose to a nitrogen cylinder with pressure | Extremely low vacuum can cause internal | |
regulator set to 150 psig (1034 kPa) and purge the hose. | arcing and compressor failure. Damage | |
S Open manifold gauge valves to break the vacuum in the line set and indoor | caused by deep vacuum operation will | |
unit. | void warranty. | |
|
SClose manifold gauge valves.
D.Shut off the nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release the nitrogen from the line set and indoor unit.
E.Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until the absolute pressure does not rise above 500 microns (29.9 inches of mercury) within a 20−minute period after shutting off the vacuum pump and closing the manifold gauge valves.
F.When the absolute pressure requirement above has been met, disconnect the manifold hose from the vacuum pump and connect it to a cylinder of HFC−410A positioned to deliver liquid refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set and indoor unit.
G.Perform the following:
SClose manifold gauge valves.
SShut off HFC−410A cylinder.
SReinstall service valve cores by removing manifold hose from service valve. Quickly install cores with core tool while maintaining a positive system pressure.
SReplace stem caps and finger tighten them, then tighten an additional one−sixth (1/6) of a turn as illustrated.
| 1/6 TURN | |
11 | 12 | 1 |
10 |
| 2 |
9 |
| 3 |
84
7 6 5
FIGURE 11
Page 10
