Outdoor Unit Installation; Air Purge - Fujitsu ASU12R2 Installation Manual

OUTDOOR UNIT

OUTDOOR UNIT INSTALLATION

Set the unit on a strong stand, such as one made of concrete blocks
G
to minimize shock and vibration.
Do not set the unit directly on the ground because it will cause trou-
G
ble.
Connector cover removal
Remove the two mounting screws.
G
Installing the connector cover
(1) After inserting the three front hooks, then insert the rear hook.
(2) Tighten the two mounting screws.

AIR PURGE

Always use a vacuum pump to purge the air.
Refrigerant for purging the air is not charged in the
outdoor unit at the factory.
Close the high pressure side valve of the gauge manifold fully and do
not operate it during the following work.
1. Check if the piping connections are secure.
2. Check that the stems of 2-way valve and 3-way valve are closed
fully.
3. Connect the gauge manifold charge hose to the charging port
of the 3-way valve (side with the projection for pushing in the
valve core).
4. Open the low pressure side valve of the gauge manifold fully.
5. Operate the vacuum pump and start pump down.
6. Slowly loosen the flare nut of the 3-way valve and check if air
enters, then retighten the flare nut.
(When the flare nut is loosened the operating sound of the
vacuum pump changes and the reading of the compound
pressure gauge goes from minus to zero.)
7. Pump down the system for at least 15 minutes, then check if the
compound pressure gauge reads -0.1 MPa (-76 cmHg, -1 bar).
8. At the end of pump down, close the low pressure side gauge of
the gauge manifold fully and stop the vacuum pump.
9. Slowly loosen the valve stem of the 3-way valve. When the
compound pressure gauge reading reaches 0.1-0.2 MPa,
retighten the valve stem and disconnect the charge hose
from the 3-way valve charging port.
(If the stem of the 3-way valve is opened fully before the
charge hose is disconnected, it may be difficult to disconnect
the charge hose.)
WARNING
(1) Install the unit where it will not be tilted by more
than 5°.
(2) When installing the outdoor unit where it may ex-
posed to strong wind, fasten it securely.
Fig. 9
Always use the screws as shown above.
Do not select the top and bottom screws incorrectly.
CAUTION
(1) Refrigerant must not be discharged into atmos-
phere.
(2) After connecting the piping , check the joints for
gas leakage with gas leak detector.
10. Fully open the valve stems of the 2-way valve and 3-way valve
using a hexagon wrench. (After the valve stem begins to turn,
turn it with a torque of less than 2.17ft•lbs (30 kgf•cm) until it
stops turning.)
11. Firmly tighten the 2-way valve and 3-way valve blank cap and
the charging port cap.
Fig. 10
Compound pressure gauge
2-way valve
3-way valve
Flare nut
Charging port
Charging port cap
Table 6
Blank cap (2-way valve) 14.47 to 18.08 ft•lbs (200 to 250 kgf•cm)
Blank cap (3-way valve) 20.25 to 23.15 ft•lbs (280 to 320 kgf•cm)
Charging port cap 9.04 to 11.57 ft•lbs (125 to 160 kgf•cm)
Tapping screw
Rear hook
Connector cover
Gauge manifold
Pressure gauge
-0.1 MPa
(-76 cmHg
LO
HI
-1 bar)
High
Low pressure pressure
side valve
side valve
(closed)
Valve stem
Charge
hose
Blank cap
Charge hose
Vacuum pump
Tightening torque