6
English
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGER-
ANT PIPING
Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filler metal (BCuP-2: JIS Z
3264/B-Cu93P-710/795: ISO 3677) which does not require
flux.
(Flux has extremely harmful influence on refrigerant piping
systems. For instance, if the chlorine based flux is used, it
will cause pipe corrosion or, in particular, if the flux contains
fluorine, it will damage the refrigerant oil.)
• Before brazing local refrigerant piping, nitrogen gas shall be
blown through the piping to expel air from the piping.
If your brazing is done without nitrogen gas blowing, a large
amount of oxide film develops inside the piping, and could
cause system malfunction.
• When brazing the refrigerant piping, only begin brazing after
having carried out nitrogen substitution or while inserting
nitrogen into the refrigerant piping. Once this is done, con-
nect the indoor unit with a flared or a flanged connection.
• Nitrogen should be set to 0.02 MPa with a pressure-reducing
valve if brazing while inserting nitrogen into the piping.
Not recommendable 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
installation method mentioned below.
After the work is finished, make sure to check that
there is no gas leak.
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
7. DRAIN PIPING WORK
〈〈
Rig the drain pipe as shown below and take measures
against condensation. Improperly rigged piping could lead
to leaks and eventually wet furniture and belongings.
〉〉
〈〈
Insulate the drain hose inside the building.
〉〉
(1) Carry out the drain piping.
• Keep piping as short as possible and slope it downwards
so that air may not remain trapped inside the pipe.
• Keep pipe size equal to or greater than that of the con-
necting pipe (Vinyl pipe of 25 mm nominal diam. and
32 mm outer diam.).
• Use the attached drain hose and clamp.
Tighten the clamp firmly.
• Insulate the clamp metal with the sealing pad.
•
There is negative pressure inside the unit relative to atmo-
spheric pressure when the unit is running, so be sure to
provide drain trap on the drain outlet. (See the figure)
•
In order to prevent foreign matter from building up
inside the piping, you should avoid curves as much
as possible, and arrange so the trap can be cleaned.
NOTE
• If converging multiple drain pipes, install according to the pro-
cedure shown below. (Install a drain trap for each indoor unit.)
• A drain trap need not be installed.
• The diameter of the piping is the same as that of the con-
necting pipe (PS1B), and should be kept equal to or
greater than that of the connecting pipe.
(2) After piping work is finished, check drainage flows
smoothly.
• Add approximately 1 liter of water slowly from the air inlet
and check drainage flow.
• Open the water supply port, add approximately 1 liter of
water slowly into the drain pan and check drainage flow.
Pipe size
Further tightening
angle
Recommended arm length of
tool
φ
6.4 (1/4”)
60 to 90 degrees
Approx. 150mm
φ
9.5 (3/8”)
60 to 90 degrees
Approx. 200mm
φ
12.7 (1/2”)
30 to 60 degrees
Approx. 250mm
φ
15.9 (5/8”)
30 to 60 degrees
Approx. 300mm
Nitrogen
Refrigerant
piping
Part to be
brazed
Taping
Pressurereducing valve
Hands
valve
Nitrogen
FXMQ40-125M(A)VE
FXMQ200 · 250M(A)VE, MAV7
FXMQ40-125M(A)VE
FXMQ200 · 250M(A)VE, MAV7
50mm or
more
50mm or
more
Bottom of unit
Attached drain hose
Metal clamp
Drain hose
Tape
4mm or less
Drain hose
Large sealing pad
(accessory)
Metal clamp
(accessory)
100mm
or more
01_EN_3P258319-6F.fm Page 6 Tuesday, June 3, 2014 11:36 AM
