Outdoor Unit Installation; Electrical Wiring (Outdoor Unit); Air Purge - Friedrich MR18C3F Installation Manual

OUTDOOR UNIT

OUTDOOR UNIT INSTALLATION

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

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.)
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.)
Fig. 9
Tapping screw
Front hooks
Rear hooks
Connector cover
11. Firmly tighten the 2-way valve and 3-way valve blank cap and
the charging port cap.
Fig. 10
Gauge manifold
Compound pressure gauge
Pressure gauge
-0.1 MPa
2-way valve
3-way valve
(-76 cmHg
LO
HI
-1 bar)
Flare nut
Low pressure
side valve
Valve stem
Blank cap
Charge hose
Charging port
Charging port cap
Vacuum pump
Table 6
Tightening torque
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)
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.

ELECTRICAL WIRING (OUTDOOR UNIT)

1. Remove the screws, then remove the control box cover.
2. Fasten the Inter unit wire harness and power supply to the conduit holder using the lock nut.
3. Connect inter-unit wire harness and power supply to the terminal.
Refer to the wiring diagram
4. Use the screws to install the control box cover.
WARNING
Be sure to comply with local codes while run-
ning the wire from the indoor unit to the out-
door unit (size of wire and wiring method, etc. ).
Every wire must be connected firmly.
No wire should be allowed to touch refrigerant
tubing, the compressor or any moving part.
Loose wiring may cause the terminal to over-
heat or result in unit malfunction. A fire hazard
may also exist. Therefore, be sure all wiring is
tightly connected.
Connect wires to the matching numbers of
terminals.
Fig. 11
Indoor unit
Terminal
Grounding line
G G
Control line
3 3
High
pressure
2 2
side valve
(closed) 1 1
DISCONNECT
(Inter Unit)
SWITCH
Charge
Power line
(FIELD SUPPLY)
hose
Indoor unit
terminal block
1 2 3 4
Earth screw
G
NOTE:
• Connector trade size for this unit is 1/2" (12.7 mm). The connec-
tor can be bought at a hardware store. Refer to "How to connect
wiring to the terminals" for instructions on connecting depend-
ing on the wire type you are using.
• The fuse located in the outdoor unit provides power supply pro-
tection and may blow when power is applied if the system has
been incorrectly wired.
Lock nut
Outdoor unit
Terminal
G G
208/230V 208/230V
208/230V 208/230V
208/230V 208/230V
Outdoor unit
terminal block
1 2 3 4 5
Disconnect switch Earth screw
Power supply line
Cord Clamp
Conduit
connector
Power supply
Inter-unit
wire harness
G