Installation manual
9
RZQ71~12 RZQ100~140B8W1B
Split System air conditioners
4PW23691-1A
If a torque wrench is not available, be aware that the tightening
torque may increase suddenly. Do not tighten nuts any further
than to the angle as listed.
■
When connecting the flare nut, apply refrigerating machine oil to
the flare (inside and outside) and first screw the nut 3 or 4 turns
by hand.
Coat here with ether or ester oil.
■
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.
A
Outdoor unit
B
Indoor unit
C
Gas piping
D
Liquid piping
E
Oiltrap
H
Install trap at each difference in height of 10 m.
■
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 oxidised
film on the inside of the pipes, adversely affecting valves and
compressors in the refrigerating system and preventing normal
operation. When brazing pipes however, do not use oxidation
preventers. Residue of such preventers may result in choking of
pipes or malfunction of components.
■
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).
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:
Procedure for leak test
Leak test must satisfy EN378-2.
1
Evacuate the pipes and check vacuum
(1)
. (No pressure increase
for 1 minute.)
2
Break the vacuum with a minimum of 2 bar of nitrogen. (Never
pressurize more than 4.0 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
.
6
If the vacuum gauge no longer rises, the stop valves can be
opened.
Piping size
Further tightening angle
Recommended arm
length of tool
Ø6.4
60°~90°
150 mm
Ø9.5
200 mm
Ø12.7
30°~60°
250 mm
Ø15.9
300 mm
Ø19.1
20°~35°
450 mm
1
Refrigerant piping
2
Part to be brazed
3
Taping
4
Hands valve
5
Pressure-reducing valve
6
Nitrogen
1
2
3
4
5
6
6
A
Pair system
B
Simultaneous operation system
1
Pressure gauge
2
Nitrogen
3
Refrigerant
4
Weighing machine
5
Vacuum pump
6
Stop valve
7
Main pipe
8
Branched pipes
9
Pipe branching kit (optional)
(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.
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.
