Daikin REQ71B8V3B, Installation Manual

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Installation manual
7
REQ71+10 REQ7 REQ71~12 REQ71B2W1B
Split System air conditioners
4PW23690-1C
Cautions for flare connection
■
Please refer to the table for the dimensions for processing flares
and for the tightening torques. (Too much tightening will end up
in splitting of the flare.)
■
When connecting the flare nut, coat the flare inner surface with
ether oil or ester oil and initially tighten 3 or 4 turns by hand
before tightening firmly.
■
After completing the installation, carry out a gas leak inspection
of the piping connections with nitrogen and such.
Cautions for necessity of a trap
Since there is fear of the oil held inside the riser piping flowing back into
the compressor when stopped and causing liquid compression
phenomenon, or cases of deterioration of oil return, it will be necessary
to provide a trap at an appropriate place in the riser gas piping.
■
Trap installation spacing. (See figure 3)
■
A trap is not necessary when the outdoor unit is installed in a
higher position than the indoor unit.
Cautions for brazing
■
Be sure to carry out a nitrogen blow when brazing.
Brazing without carrying out nitrogen replacement or releasing
nitrogen into the piping will create large quantities of oxidized
film on the inside of the pipes, adversely affecting valves and
compressors in the refrigerating system and preventing normal
operation.
■
When brazing while inserting nitrogen into the piping, nitrogen
must be set to 0.02 MPa with a pressure-reducing valve (=just
enough so that it can be felt on the skin).
(See figure 6)
E
VACUATING
■
Do not purge the air with refrigerants. Use a vacuum pump to
vacuum the installation. No additional refrigerant is provided for
air purging.
■
Pipes inside the units were checked for leaks by the
manufacturer. The refrigerant pipes fit on site are to be checked
for leaks by the installer.
■
Confirm that the valves are firmly closed before leak test or
vacuuming.
Set up for vacuuming and leak test:
(See figure 5)
Procedure for leak test
Leak test must satisfy EN378-2.
C
HARGING REFRIGERANT
Important information regarding the refrigerant used
This product contains fluorinated greenhouse gases covered by the
Kyoto Protocol. Do not vent gases into the atmosphere.
Refrigerant type: R410A
GWP
(1)
value: 1975
(1)
GWP = global warming potential
Please fill in with indelible ink,
■ ➀
the factory refrigerant charge of the product,
■ ➁
the additional refrigerant amount charged in the field and
■ ➀
+
➁
the total refrigerant charge
on the fluorinated greenhouse gases label supplied with the product.
Piping
size
Flare nut
tightening torque
A dimensions
for processing
flares (mm) Flare shape
Ø9,5 33~39 N•m 12,8~13,2
Ø15,9 63~75 N•m 19,3~19,7
Ø19,1 98~110 N•m 23,6~24,0
A Outdoor unit
B Indoor unit
C Gas piping
D Liquid piping
E Oiltrap
H Install trap at each difference in height of 15 m.
1 Refrigerant piping
2 Part to be brazed
3 Taping
4 Hands valve
5 Pressure-reducing valve
6 Nitrogen
R=0.4~0.8
45
° ±
2
90
°± 2
A
1 Pressure gauge
2 Nitrogen
3 Refrigerant
4 Weighing machine
5 Vacuum pump
6 Stop valve
1
Evacuate the pipes and check vacuum
(1)
. (No pressure increase for 1
minute.)
(1) Use a 2-stage vacuum pump with a non return valve which can evacuate to
–100.7 kPa (5 Torr, –755 mm Hg).
Evacuate the system from the liquid and gas pipes by using a vacuum pump for
more than 2 hours and bring the system to –100.7 kPa. After keeping the system
under that condition for more than one hour, check if the vacuum gauge rises or
not. If it rises, the system may either contain moisture inside or have leaks.
2 Break the vacuum with a minimum of 2 bar of nitrogen. (Never pressurize
more than 4.15 MPa.)
3 Conduct leak test by applying soap water, etc. to the connecting part of
the pipes.
4 Discharge nitrogen.
5
Evacuate and check vacuum again
(1)
.
6 If vacuum gauge does no longer rise, the stop valves can be opened.
NOTE Following should be executed if there is a possibility of
moisture remaining in the pipe (if piping work is carried out
during the raining season or over a long period of time,
rainwater may enter the pipe during work).
After evacuating the system for 2 hours, pressurize the
system to 0.05 MPa (vacuum break) with nitrogen gas and
evacuate the system again using the vacuum pump for
1 hour to –100.7 kPa (vacuum drying). If the system
cannot be evacuated to –100.7 kPa within 2 hours, repeat
the operation of vacuum break and vacuum drying. Then
after leaving the system in vacuum for 1 hour, confirm that
the vacuum gauge does not rise.
After air purging with a vacuum pump it may happen that
the refrigerant pressure does not rise, not even if the stop
valve is opened. Reason for this phenomenon is the closed
state of for instance the expansion valve in the outdoor unit
circuit, but this is not a problem for running the unit.