Daikin FXHQ12MVJU Installation Manual Download

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Not recommended but in case of emergency

You must use a torque wrench, but if you are obliged to install
the unit without a torque wrench, you may follow the installa-
tion method mentioned below.
When you keep on tightening the flare nut with a spanner, there
is a point where the tightening torque suddenly increases. From
that position, further tighten the flare nut the angle shown below :

Table 3

After the work is finished, make sure to check that there
is no gas leak.

6-3 BRAZING REFRIGERANT PIPING

CAUTION

• CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT

PIPING

“Do not use flux when brazing refrigerant pipe. Therefore, use
the phosphor copper brazing filler metal (BCuP) which does not
require flux.”
(Flux has an extremely negative effect on refrigerant piping sys-
tems. For instance, if chlorine based flux is used, it will cause
pipe corrosion. If the flux contains fluorine, it will damage the
refrigerant oil.)

• Before brazing local refrigerant pipe, nitrogen gas shall be

blown through the pipe to expel air from the pipe.
If you brazing is done without nitrogen gas blowing, a large
amount of oxide film develops inside the pipe, and could
cause system malfunction.

• When brazing the refrigerant pipe, only begin brazing after

having carried out nitrogen substitution or while inserting
nitrogen into the refrigerant pipe. Once this is done, connect
the indoor unit with a flared or a flanged connection.

• Nitrogen should be set to 2.9 psi with a pressure-reducing

valve if brazing while inserting nitrogen into the pipe.

(Refer to Fig. 15)

DANGER

• Use of oxygen may cause an explosion resulting in serious

injury or death. Only use nitrogen gas.

CAUTION

• Be sure to insulate any field piping all the way to the piping

connection inside the unit. Any exposed piping may cause
condensate or a burn if touched.

6-4 PIPING INSULATION

• Make absolutely sure to execute thermal insulation works on

the pipe-connecting section after checking gas leakage by

thoroughly studying the following figure and using the insula-
tion pipe cover (6) and (7). (Fasten both ends with the clamps
(4).)

(Refer to Fig. 16)

• Wrap the small sealing pad (9) only around the insulation for

the joints on the gas piping side.

(Refer to Fig. 16)

(1) For piping facing back.

• Remove the rear metal plate for pipe.

(Refer to Fig. 17)

• The figure of the direction of back shows when both the piping

and drain pipe are set backward.
When setting the piping to face up or right, attach the rear metal
plate for refrigerant pipe and plug a hole for drain pipe. (See “4
PREPARATIONS BEFORE INSTALLATION” (3-3) on page 6)

(2) For piping facing up.

• When setting the piping to face up, the L-shaped branch pipe

kit sold separately is required.

• Removing the top penetration lid and use the L-shaped branch

pipe kit sold separately to set the pipe.

(Refer to Fig. 18, 19)

(3) For piping facing right.

• Cut out a slit hole on the decoration panel (right) and set the

pipe.

(Refer to Fig. 17)

Pipe size (in.) Further tightening angle Recommended arm length of tool (in.)

1/4