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(9) Outdoor unit installation (10) Air tightness test (11) Vacuum drying (12) Additional refrigerant charge
(1) Sleeve work (2) Indoor unit
installation (6) Duct work (indoor)
(3) Piping support
(5) Drain piping work (8) Control wiring work (4) Refrigerant piping work
Schematic Drawing of VRV Installation
· Flaring
· Bending
· Pipe expansion
(7) Insulation work
1. Work Flow by Process
– 1 –
<Process> <Key Points> <Page>
Pre-work
Determination of the work classification
Preparation of the installation drawing Work
(1) Sleeve work ...........................Consider the downward gradient of the drain p ipes.·························································· 2 (2) Indoor unit installation .............Confirm the model names to avoid any installation mistakes.··········································· 3 (3) Piping support ........................Use support s within the designated support intervals.························································ 5 (4) Refrigerant piping work .........Pay attention to the principles of dry, clean and tight.··························································9 (5) Drain piping work ..................Maintain a downward gradient of at least 1/100.·······························································22 (6) Duct work (indoor) ................Ensure that a sufficient airflow is maintained. ···································································26 (7) Insulation work ......................Ensure that there are no gaps at the joints between insulation materials.···························27 (8) Control wiring work ...............Use applicable two-core wires.··························································································30 (Do not use multi-core.) (9) Outdoor unit installation ........Make considerations to prevent short-circuiting and maintain a workspace for servicing. 32 (10) Air tightness test ……………Make a final confirmation that there is no pressure drop at 4 MPaG(580 PSI) for 24 hours.34 (11) Vacuum drying ……………….Use a vacuum pump that can vacuum –100.7 kPaG(-14.6 PSI) or lower……………….. 36 (12) Additional refrigerant charge ...Enter the additional refrigerant charge amount onto the outdoor unit and the log book.····39
The above order represents the general procedure. It may differ depending on the local conditions and actual circumstances.
*Please note that lengths without any units are all in millimeters (mm) throughout this document.
Legend
Caution: Points of caution at the job site
One point lesson: Expertise gained from onsite work
Case example: An actual example of onsite work
2. Work by Process and Key Points (1) Sleeve work
– 2 –
D L1 R1
L3
R2
L2
D L1 R1
L3
R2
L2
ê Note that the beam structure limits the allowable area for the placement of through-holes.
� Cover both ends of the sleeves with masking tape to prevent any concrete from entering
%UDQFK * DV�/ LQH P P
/ LTXLG�/ LQH�P P
' UDLQ�3LSH�P P
H/P or
C/O
+XPLGLW\
' HOKL 19 13 6 H/P / RZ
$KPHGDEDG 19 13 6/ 9 H/P / RZ
3XQH 19 9 6 C/O / RZ
0 XPEDL 19 19 6 C/O +LJK
%DQJDOXUX 19 9 6 C/O / RZ
&KHQQDL 19 13 6 C/O +LJK
+ \ GHUDEDG 19 13 6/ 9 C/O / RZ . RONDWWD 19 13 6 C/O +LJK
&KDQGLJDUK 19 13 6 H/P +LJK
' DLNLQ�6WDQGDUG
19 13 6 H/P +LJK
Work procedure
Meeting with the construction
company
Determination of the location and sleeve diameter
Installation Confirmation
~Working points~ ¿ Determination of the placement of the through-holes � Determine the placement so that the drain piping is at a downward gradient of at least 1/100. � Consider the thickness of the insulation material when determining the sleeve diameters for
refrigerant piping and drain piping.
At least 3 x [(R1 + R2)/2]
At least D/2
Location into which the sleeve cannot be inserted through the beam
At least D/4 and 150 mm
2. Work by Process and Key Points (2) Installation of indoor units
– 3 –
Drain side
Piping side
Drain side
Piping side
1) 2) 3) 4)
1) Transporting (1) Determine the transporting route. (2) Transport the indoor units to the installation location in the original packing. Do not remove the packing until it
is to be installed. (3) When receiving the products, be sure to check for any blemishes or dents.
� How to prevent the installation of the wrong indoor unit model or in the wrong location.
Before transporting the indoor unit, attach a sheet of paper to a visible spot on the packing that notes the installation location and the system number.
2) Determination of installation location
The following explains the procedure in the event an insert is not contained within the package.
(1) Confirm the space required for servicing and installation. (2) Confirm the piping direction and air discharge direction.
ê The space required for servicing and installation may differ depending on the model. Please confirm the details in the installation manual or the like.
(3) Mark the center of the indoor unit with chalk lines, using the base point lines drawn on the floor as a guide.
(4) Using the upper packing material, mark the suspension locations on the floor based on the
center of the unit. (5) Use a laser pointer or the like to transfer the suspension location from the floor to the ceiling slab, and use a drill
to open up a pilot hole.
ê If a pilot hole for the anchors leads to a steel beam, be sure to try another location for the hole.
1F reception room AC1-1
Installation space for FXFQ
Suspension location Laser pointer
Ceiling
Trans- porting
~Working points~ Installation procedures differ according to the indoor unit model. Be sure to conduct all work according to the accompanying installation manual.
At least 1,500 mm
At least 200 mm
At least 1,500 mm
At least 1,500 mm
At least 1,500 mm At least 200 mm
Work procedure
Center of the unit
Base point line
Unit suspension location
Upper packing material
Determination of installation location
Indoor unit installation
Installation of suspension bolts
2. Work by Process and Key Points (2) Installation of indoor units
– 4 –
(2)Installation of indoor units
– 5 –
3) Installation of suspension bolts (1) Determine the length of the suspension bolts according to the height of the installation. (2) Before installing, place the nuts (2; locally procured parts) and washers (2; accessories) on the suspension bolt
(double-nut on the lower side of the bolt).
(3) After installing, adjust the nut on the lower side to the installation height. (4) For the upper washer, use the attached washer plate to secure.
ê Check the installation manual for the installation height when attaching optional accessories.
� The height of the indoor unit can easily be adjusted by loosening the double nut. Re-tighten the double nut after completing adjustment.
� The suspension bolt size (M10 or W3/8) is compatible with all models. � If the suspension bolt length is 1.5 m or longer, attach a steady brace
on the longitudinal side of the suspension pitch.
4) Indoor unit installation (1) Install the indoor unit level. (2) When installing manually, first hook the main unit's suspention bracket onto the suspension bolts on opposing
corners to suspend the indoor unit. And, if suspending the indoor unit with a device such as a lifter, remove the lower nut on the suspension bolt before doing so.
(3) After installing the indoor unit, be sure to protect it with a plastic bag or the like.
ê If you assume that the temperature and humidity in the ceiling space exceed 30°C and RH80%,
reinforce the insulation (thickness) of the indoor unit. (Use polyethylene foam or glass wool with a thickness of at least 10 mm.)
¿ How to protect the indoor unit <Left unprotected> <Protected>
¢ Why protect it? Dust and the like can get on the filter and heat exchanger, adversely affecting capacity.
ê After all work is complete, be sure to remove the protective plastic covering and the like from the indoor unit.
Washer plate (accessory)
Insert
[Secure the washer]
Upper nut
Washer (accessory)
Suspension bracket
Tighten (double-nut)
An example of steady brace installation
Steady brace bolt
At l
east
1,5
00
2. Work by Process and Key Points (3) Piping support (Refrigerant and drain)
– 6 –
300~
500
150015001500150015001500
300~ 500
Indoor unit
Refrigerant piping Ø19.1/Ø9.5
Supporting fixture
Horizontal pipe
Vertical pipe
1) 2)
1) Determination of location ¿ Interval for refrigerant piping support
<Horizontal pipes>
<Vertical pipes>
� Adjust based on the liquid piping size when the liquid and gas piping are suspended together.
ê Upon start and stop of the air conditioner, refrigerant pipes expand or contract due to
temperature differences. While it may depend on the particular operation state, the pipi ng can expand or contract 10 mm for every 10 meters. Therefore, be sure to adhere to the required support interval.
¿ Interval for drain piping support (in the case of polyvinyl-chloride pipes)
<Horizontal pipes>
<Vertical pipes>
Pipe outer diameter (mm) =19.1 22.2~44.1 Support interval (m) =1.0 =1.5
Pipe outer diameter (mm) =44.45 Support interval (m) =1.5
Pipe inner diameter (mm) =40 =50 Support interval (m) =1.0 =1.2
Pipe inner diameter (mm) =44 =56 Support interval (m) =1.5 At least one spot per floor
Determination of location
~The purpose of piping supports~ <Support of horizontal pipes> 1. Prevention of sagging due to their own weight 2. Prevention of spot overloading due to pipe expansion and contraction as a result of
temperature differences <Support of vertical pipes> 1. Prevention of swaying and buckling due to their own weight
Work procedure
Installation of suspension bolts and supporting fixtures
(3) Piping support
– 7 –
Suspension band with turnbuckle
Support of horizontal refrigerant piping
Suspension band with turnbuckle
Polyvinyl pipe
Suspension bolt supporting fixture (for shaped steel)
Suspension bolt supporting fixture (for flat decks)
Vertical piping support (example)
2) Installation of suspension bolts and supporting fixtures ¿ Horizontal piping support
� Minimize the length of the suspension bolts � Consider the downward gradient when determining the
length of the drain piping suspension bolts. � When supporting the refrigerant piping, place a hard pad
(e.g., polyvinyl-chloride pipe of width 150mm) between the supporting fixture and insulation material as shown in the photo to the right in order to prevent crushing of the insulation material
from the weight of the piping.
ê Never provide additional piping support from the piping.
¿ Vertical piping support
� Allow sufficient space for maintenance and insulation installation when determining the distance between the unit body surface and piping as well as the piping interval when many pipes are laid in parallel.
Legs for vertical band Vertical band
Battledore bolt T-shape leg with washer
Special supporting fixtures for vertical piping
Brazing areas
~Working points~ � Attach refrigerant piping support on top of the insulation material. � With regard to drain piping support, first secure the pipes directly with the supporting fixtures
and then place the insulation materials on top of this. · ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Anchor
Leg for v ertical band
Vertical band
(3) Piping support
– 8 –
300~ 500 300~ 500
300~ 500
300~ 500 300~ 500
300~ 500
A+ B+ C= 300~ 500
B
C
A
A+ B+ C= 300~ 500
B
C
A B
C
A
¿ Spot support (refrigerant piping)
¢ Support of refrigerant piping branch and bend
� As shown in the above illustration, it is easier to support the branch piping branches if a
different interval is used for each support.
¢ Support around the indoor unit
¢ Through-hole support
Support points
=300
=300
Support point
300~500
Support points
Support point
~Purposes~ 1. Prevention of overload on areas due to expansion 2. Prevention of overload on the connecting area to the unit due to expansion 3. Prevention of impact on waterproofing due to expansion
300~500
(3) Piping support
– 9 –
¿ Spot support (drain piping)
¢ Bend support
¢ Support around the indoor unit
� The horizontal section of the drain piping after the first upward section � The piping connection with the drain hose
accessory
¢ Through-hole support
Drain hose accessory
Support point
300~500 300~500
Support points
=300
=300
2. Work by Process and Key Points (4) Refrigerant piping work
– 10 –
~Working points~ � Adhere to the following three basic principles when conducting refrigerant piping work:
1) 2) 3)
1) Protection (covering) Protection (covering) during storage and work involving refrigerant piping is the most important type of work in order to prevent water/moisture, contaminants or dust from entering into the piping.
ê If water/moisture, contaminants or dust enter into the refrigerant piping, not only will it prevent
the air conditioner from operating normally but it will also cause a malfunction of the machine and significant inconvenience for the customer. Your utmost effort is required in preventing this from occurring.
¿During storage (1) Make sure to protect (cover) both pipe ends. ê Do not use piping that has not been protected (covered).
(2) Do not lay refrigerant pipes directly onto a floor surface, but use a table or the like when placing them.
Dry Clean Tight
No water/moisture inside
Do not let water/moisture in
No dust/contaminants inside
Do not let dust/contaminants in No leakage of refrigerant
[The 3 basic principles of refrigerant piping]
Protection (covering)
Pipe processing
Work procedure
<Unprotected (uncovered) pipe ends> <Protected (covered) pipe ends>
Water/ moisture
sytamints Leak
Unit connection
2. Work by Process and Key Points (4) Refrigerant piping work
– 11 –
¿During work
(1) Be sure to protect (cover) the ends even when leaving the pipes for a short period of time . (2) Be sure to protect (cover) the ends when pushing a pipe through a through-hole.
<Unprotected (uncovered) pipe ends> <Protected (covered) pipe ends>
[How to protect (cover)]
The most reliable is the 'pinch method,' but taping can also be selected as an easy method depending on the site and time frame.
<Pinching>
A method by which the ends of the copper tube are closed off and the gaps are brazed.
<Taping>
A method by which the ends of the copper tube are covered with vinyl tape
Site Work period Protecting (covering) method
1 month or more Pinching Outdoor
Less than 1 month Pinching or taping
Indoor Not considered Pinching or taping
Pipe end
Wrap the copper tube with tape.
Cut flat
Fold down Wrap with tape again
Copper tube
Braze
Brazing filler metal
(4) Refrigerant piping work –Protection-
– 12 –
2) Pipe processing ¿Flaring…This is one method of connecting refrigerant piping of a diameter of 19.1 mm or smaller to an air
conditioner. <Tools>
<Work procedure> (1) Pipe cutting
� Use a pipe cutter with left rotation.
� Feed the blade of the pipe cutter bit by bit into the pipe with each rotation. ê Excessive feeding of the blade can disfigure the pipe so s pecial care is required.
(2) Processing of the cut surface
� Remove burrs from the tip of the cut surface with a file.
� Remove burrs from the inner portion of the pipe, using a reamer or scraper. � Use the file again in order to remove burrs from the tip. � Use the reamer or scraper again in order to remove burrs from the inner portion of the pipe.
ê When processing the cut surface, face it down to prevent any swarf from falling into the pipe. ê Make sure that the burrs are completely removed, as not removing the burrs sufficiently can
result in a refrigerant gas leak at the flare.
(3) Flaring
� Insert a flare nut into the pipe before flaring. � Ensure that the size of the flare is within the prescribed range.
� Note that an appropriate size for the flare is virtually the same as that
of the union.
ê The size of the flare will become larger in proportion to Dimension A to the right. Note that Dimension A differs according to the flaring tool manufacturer.
Pipe cutter
Reamer
Flaring tool
File
Facing down
Facing down
Burrs
Scraper
X Y
X≅Y
A
(4) Refrigerant piping work –Bending-
– 13 –
045
90
R
045
90
LR
Clamping lever
Handle
Handle
Pipe
YY
¿Bending…Some of the tools used to bend refrigerant pipes are electric-type, hydraulic-type, lever-type and ratchet-type benders . Following is a description of the work procedure with a lever-type bender:
<Tools>
<Work procedure> ¢ The bending dimensions depend on whether they are taken from
the left or right end.
(1) Measure the finished dimensions from the right or left end of the pipe.
(2) Insert the pipe into the bender.
� Align the end of the handle with the '0' mark on the clamping lever.
(3) Align the mark on the pipe with the 'R' or 'L' on the handle by adjusting the pipe.
(4) Move the handle to bend the pipe to the desired angle.
ê Bend the pipe slowly to prevent pleating or deformation of the inner curve of the pipe.
ê Do not bend beyond 90°. ê Make sure the minimum thickness (for pipe dia 6.4mm~12.7mm)
Is 0.8mm, and should be 1.0 mm for pipe dia 15.88mm.
¢ If the handle does not have the 'L' mark (1) Mark the finished dimension from the left end.
(2) Insert the copper tube into the bender � Align the end of the handle with the '0' mark on the clamping lever.
(3) Insert the same size of pipe into the bender slot so that the pipe becomes parallel to the clamping lever. Align the center line (middle) of that pipe with the mark on the pipe.
(4) Use the handle to bend the pipe to the desired angle.
X
Deformation due to pleating Deformation due to
damage Appropriate bend
Lever-type bender
End of the handle
Mark
X
0
From the right
From the left
Same size of pipe
End of the handle
Mark
Y
Clamping lever
0
(4) Refrigerant piping work –Pipe expansion -
– 14 –
¿Pipe expansion…Two pipes can be connected by expanding the end of the refrigerant pipe, inserting the other pipe in question inside and brazing the connection.
<Tools>
<Work procedure> (1) Remove the burrs on the cut surface with a reamer or scraper.
ê Note that excessive deburring can thin the walls of the pipe and cause vertical (lengthwise)
cracking when expanding.
(2) Slightly expand the tip of the head.
(3) Insert the other pipe fully into the tip portion of the head, close the lever and expand the pipe.
(4) This may leave vertical scratches on the inner surface of the pipe so rotate the pipe to remove them.
Expander
(4) Refrigerant piping work –Pipe expansion -
– 15 –
¿Brazing…Brazing refers to the use of a metal with a lower melting temperature than that of the base metal as well as the alloy of these metals as solder in order to joint the two base metals without melting them. To heat the solder, a combustion flame of flammable gas (e.g., acetylene, propane) and oxygen is used. The following is an explanation of the work procedure when using acetylene:
ê If certification is required in your country, be sure to have all work conducted by a certified
individual. ê Be sure to wear all the necessary protective gear (e.g., eye protectors, leather gloves), as fire is
being used. ê Always have handy fire prevention equipment such as a fire extinguisher. ê For solder, use a phosphor copper metal (silver composition: 0%). ê Don't use a cutting torch.
<Tools> ¢ For brazing
� In order to ensure safety when lighting the flame, be sure to use an acetylene regulator with a
flashback arrester.
[Standards for selecting the outer diameter of the pipe to be brazed and nozzle diameter (French standards)]
Outer diameter Nozzle diameter (mm) Nozzle number
F6.4
F9.5 F12.7
F15.9
F19.1
1.2 #200
F22.2 1.3 #225
F25.4 1.4 #250
F31.8 1.5 #315 F38.1 1.6 #400
F44.5 1.7~1.8 #450~500
ê If the nozzle is too large, it makes preheating and heating difficult. If too small, brazing takes too long. Use a nozzle that suits the outer diameter of the pipe to be brazed.
¢ For nitrogen replacement
Welding torch
Oxygen regulator
Acetylene regulator (with flashback arrester)
Twin hose
Welding kit
Nitrogen cylinder Nitrogen gas regulator Pressure hose
Valve
Tapered nozzle
(4) Refrigerant piping work – Brazing-
– 16 –
N2 N2N2N2 N2
<Work procedure> Procedure 1. Confirmation of an appropriate gap between the pipe and joint
� An appropriate gap is when the pipe can be inserted into the joint and held upside down
without falling.
Procedure 2. Nitrogen replacement ¢ Purpose
A voluminous oxide film develops on the inner surface of the pipe during brazing. The film can clog, among other parts, the solenoid valve, capillary tube and compressor's oil pump inlet, hampering normal operation. In order to prevent this from occurring, it is necessary to replace the air within the pipe with nitrogen. This work is referred to as nitrogen replacement.
(1) Set up the required tools as shown below:
� It is even more effective to open up a small hole in the tape to release the nitrogen after
covering the end of the pipe with tape or the like. � Use of the tapered nozzle results in efficient replacement.
(2) Adjust the nitrogen gas pressure to 0.02(MPaG) or so.
ê If the nitrogen pressure is too high, it may cause the brazing filler metal (solder) not to reach completely around the pipe or pinholes to develop in it. Make sure that the pressure is not excessively high.
ê Use of nitrogen with a purity of at least 99.99% is recommended. Be sure to note that use of a lesser purity nitrogen may likely result in oxide film formation.
The effects of nitrogen replacement
Taping Tapered nozzle Valve
Nitrogen gas regulator
Nitrogen cylinder
Taping Pressure hose
No nitrogen replacement The inner surface of the pipe has blackened
due to the oxide film.
Nitrogen replacement The inner surface of the piping is clean.
(4) Refrigerant piping work – Brazing-
– 17 –
A and B Large temperature difference
Uniform temperature around the
circumference
600°C 780°C 780°C
780°C
400°C
600°C 780°C 780°C
Non-uniform temperature around the circumference
A and B Same temperature
B A
B
A
Procedure 3. Preheating <The five key points for preheating>
Point 1: Heat both base metals evenly. (The inner and outer pipes and the circumference)
Point 2: Heat until an appropriate temperature for applying the brazing filler metal (solder). 640~780°C (where the base metals change color from reddish black to red)
Point 3: Torch flame adjustment and flame intensity adjustment � Conduct brazing with a reducing flame.
(Roughly a 5 cm carburizing flame) � Change the flame intensity according
to the size of the base metal.
Point 4: Flame angle (heat control)
� Make the flame angle 80 to 85°.
80–85°
Flame core
Carburizing flame
Outer flame
Inner pipe
Outer pipe
Inner pipe
Outer pipe
Appr
opria
te
heat
ing
rang
e
Bro
ad h
eatin
g ra
nge
Roughly 5 cm
Too early to apply the brazing filler metal
(base metal temperature of 500 to 600°C)
Appropriate timing for application of solder material
(base metal temperature of 640 to 780°C)
Too late to apply the brazing filler metal
(base metal temperature of 800 to 1,000°C)
Roughly 5 cm
(4) Refrigerant piping work – Brazing-
– 18 –
Carburizing flame Carburizing flame
Point 5: Visual confirmation � Distance from the carburizing flame tip � Flame location � Flame direction
Procedure 4. Brazing filler metal application <Five key points when applying the brazing filler metal>
Point 1: Confirm the range of brazing filler metal application (spread range)
Roughly 5 mm
2~3mm
Distance from the carburizing flame tip Flame location
Flame direction
2~3 mm Flame loss
Overlap Not overlapping results in a gas leak
(4) Refrigerant piping work – Brazing-
– 19 –
Point 2: Confirm the volume of the brazing filler metal flow (differs according to the base metal heating range)
Point 3: Melt the brazing filler metal from the rod tip (melt it gradually, gently applying it upon the base metal)
Point 4: The angle of flame and brazing filler metal � Increase the flame angle slightly compared to preheating
� Make the angle between the brazing filler metal and flame roughly 90°.
During preheating
During brazing
Appropriate heating range
Excessively broad heating range
Excessively narrow heating range
Excessive flow of brazing filler metal
Lack of flow of brazing filler metal
Brazing filler metal
Brazing filler metal
Roughly 90°
80~85°
Hanging brazing filler metal
(4) Refrigerant piping work – Brazing-
– 20 –
Point 5:Confirm visually. (Final confirmation of the distance from the carburizing flame tip, location of flame on the pipe
� It is relatively easy to apply the brazing filler metal when the pipe is facing down or side ways. But, if the pipe is facing up, it is relatively difficult to spread it and can result in a refrigerant leak. Therefore, make efforts to enable brazing with the pipe facing down or sideways.
� Do not turn off the nitrogen until the pipe is completely cooled down. If the nitrogen gas is stopped before the pipe has sufficiently been cooled down, it will result in the development of an oxide film on the inner surface of the pipe.
1~2 mm
Distance from the carburizing flame tip
Location of flame on the pipe
Flame direction (Move the flame up/down and
left/right at a right angle to the pipe)
Final confirmation
2~3 mm
Facing down Facing sideways Facing up
Relatively easy Relatively difficult
(4) Refrigerant piping work – Refrigerant branch pipe (REFNET joint) –
– 21 –
AA
¿ Refrigerant branch pipe (REFNET joint) <Installation standards>
1. Install the REFNET joint horizontally or perpendicularly.
2. Install the REFNET header horizontally.
Example of liquid-side header installation Example of gas -side header installation
� Create at least 500 mm of a straight pipe section before and after branches when connecting refrigerant branch pipe to the field pipe. <Reason> Bending the pipe too close to the branch can lead to complaints about abnormal noise.
¿ Example of refrigerant branch pipe installation <Installed at a 90° angle> <Installed horizontally>
¢ Installing the REFNET joint while it is leaning at an angle can cause refrigerant drift, resulting
in abnormal noise or preventing normal operation. Be sure to install it horizontally.
Horizontal
Perpendicular
At least 500
At least 500 At least 1,000
Ceiling
Supporting fixture (locally procured)
Horizontal Horizontal
Ceiling
Mount (locally procured)
A. Arrow view <Horizontal pipe> <Vertical pipe>
<Top view>
(4) Refrigerant piping work – Flare connection –
– 22 –
3) Unit connection ¿Flare connection
<Tools, etc.>
<Work procedure> (1) Apply refrigerant oil (ethereal oil, ester oil) to the inner
surface of the flare . (2) Turn the flare nut 3 or 4 times to the machine union side by hand. ê Be sure to use the flare nuts that come with the unit.
ê If the flare nut cannot be turned by hand, there may be a shaft misalignment of the flare and union. Please try again.
(3) Tighten to the prescribed torque value using the torque wrench
ê Tighten, using a technique that employs both the torque wrench and (spanner) monkey wrench.
ê Be careful, as tightening excessively can cause gas leakage due to flare nut cracking and the like.
� When tightening with a spanner (monkey wrench) because a torque wrench is unavailable: � When tightening a flare nut with a spanner, there comes a point where the tightening torque
increases rapidly. From that point, tighten only with an angle shown in the table below.
ê Note that tightening the flare nut with a spanner longer than the recommended tool length shown in the table below can result in excessive tightening.
� Marking the flare nut with a magic marker or the like after it has been tightened prevents the worker from forgetting to tighten the flare nut.
Tightening torque standards for flare nuts
Pipe outer diameter Tightening torque (N•cm)
F 6.4 1420~1720 F 9.5 3270~3990
F 12.7 4950~6030 F 15.9 6180~7540 F 19.1 9720~11860
Pipe outer diameter Tightening angle (rough standard)
Recommended length of tool being used
F 6.4 60°~90° Approx. 150 mm
F 9.5 60°~90° Approx. 200 mm F 12.7 30°~60° Approx. 250 mm F 15.9 30°~60° Approx. 300 mm
F 19.1 25°~35° Approx. 450 mm
Torque wrench
Refrigerant oil
Marking
Where the refrigerant oil is applied
Tool length
2. Work by Process and Key Points (5) Drain piping work
– 23 –
H
H
H
H
1) 2) 3)
ê Do not connect drain pipes to the building's sanitary sewer pipes or waste pipes as it may cause an odor problem.
¿ Reverse gradient of the drain piping In some cases it is difficult to ensure the required drain piping gradient within the ceiling spaces when other piping and equipment crowd the area. Most of such problems can be averted by prior consultation with the installers handling the other equipment.
1) Indoor unit side drain piping
ê The installation procedures for drain piping at the indoor unit side differ by the model, so always check the installation manual before installing.
ê Indoor units (FXMQ) in which the drain piping connection becomes a negative pressure require a drain trap (see below) for each unit. In addition, the drain trap requires a cleanout for cleaning.
Work procedure
Drain flow test
~Working points~ � Ensure a downward gradient of the drain piping of at least 1/100. � Keep the drain piping as short as possible in order to prevent air pockets.
Indoor unit FXMQ
Indoor unit FXMQ
H: At least 50 mm
Drain trap
Cleanout
Attach a cleanout to allow for cleaning
Example of drain trap installation
Indoor unit
Downward gradient of at least 1/100 (1 cm/1 m)
1/100 gradient
Collective drain piping
Indoor unit side drain
piping
Indoor unit installation
(5) Drain piping work
– 24 –
Drain-up height
Main drain piping
<Work procedure> (1) Connect the attached drain hose (flexible type) to the indoor unit 's drain outlet. ê Be sure to use the drain hose that comes with the unit.
The flexible type prevents any undue stress on the drain pan. ê Do not bend the drain hose in the middle so as to prevent any excessive force on it. Bending
can lead to a water leak.
(2) Tighten the indoor unit 's drain connection and drain hose with the attached hose band.
ê Do not attach the indoor unit's drain connection and drain hose (accessory) with adhesive. It complicates removal of the drain hose from the machine during maintenance and the like.
(3) Install the drain branch piping up to the main drain pipe.
� Refer to the illustration below for connection from the indoor unit to the main pipe.
¿ If the main drain pipe has already been installed and the required gradient for the drain branch piping cannot be achieved, maximize the drain-up height. (Confirm the drain-up height with the installation manual as it differs depending on the model.)
Indoor unit
Example of installation
Allows for adjustment of the angle
Drain pain Insulation material (band section)
Insulation material (piping section)
Attached drain hose
Hose band
Drain branch piping
Main drain pipe
(5) Drain piping work
– 25 –
2) Collective drain piping
� An example of a connection from the main drain pipe to a vertical pipe
It is ideal to use a Y joint. If it is not locally available, a T joint can also be used.
� Maximize the size of the main dr ain pipe as much as possible. � Attach a cleanout (cap) at the top of the main drain pipe for water flow tests. � Minimize the number of indoor units per group as few as possible in order to prevent the
drain piping from becoming too long.
Connection to vertical pipe with a Y joint Connection to vertical pipe using a T joint
Cleanout
T joint Y joint
Example of drain piping installation
Main drain piping
Vertical drain piping
Vent piping
Drain branch piping
(5) Drain piping work
– 26 –
3) Drain flow test (1) Conduct a drain flow test before insulation work. (2) Use the cleanout on the main drain pipe for the water flow test.
� In the case of polyvinyl piping, use of colored adhesive prevents workers from forgetting to
replace the plug.
(Reference) Inner diameters of the main drain piping and vertical drain piping
� Calculate the drainage volume based on the number of indoor units connected to the main drain pipe. The inner diameter of the piping can be determined using the following method: � 6 liters per hour per 1 HP is a rough measure for drainage volume from the indoor units.
For example, in the event of 3 units with 2 HP and 2 units with 3 HP: 6 L/hr × 2 HP × 3 units + 6 L/hr × 3 HP × 2 units = 72 L/hr.
(1) The relationship between the inner diameter of the main drain pipe and allowable drainage volume when using
collective piping (in the case of an air vent)
Note: Calculated assuming that the water ratio within the piping is 10%. Round off the allowable flow rate to the nearest whole number. The pipe after collection should have an inner diameter of at least 34 mm.
(2) The relationship between the inner diameter of the vertical drain pipe and allowable drainage volume when using collective piping (in the case of an air vent)
Note: Round off the allowable flow rate to the nearest 10. Vertical pipes within collective piping should have an inner diameter of at least 34 mm.
Allowable flow rate [L/hr] PVC
Inner piping diameter
(Reference value: mm) Gradient=1/50 Gradient= 1/100 Comments
PVC25 19 39 27
PVC32 27 70 50
Not suitable for the main drain piping due to the limited allowable flow rate
PVC40 34 125 88
PVC50 44 247 175
PVC63 56 473 334
Suitable for the main drain piping
PVC Inner piping diameter
(Reference value: mm) Allowable flow rate [L/hr] Comments
PVC25 19 220
PVC32 27 410
Not suitable for vertical drain piping in the case of collective piping
PVC40 34 730
PVC50 44 1,440
PVC63 56 2,760
PVC75 66 5,710
PVC90 79 8,280
Can be used for vertical drain piping in the case of collective piping
– 27 –
~Noise and vibration considerations~ � Be sure to use canvas joints between the indoor unit and suction ducts as well as the indoor unit and
discharge ducts. This is because they are useful in preventing reverberations when the product 's vibrations and operating noise travel through the building and ducts.
� Select suction and discharge grilles in consideration of the airflow rate so as to prevent any air distribution
noise (wind roar).
2. Work by Process and Key Points (6) Duct work (indoor)
BE SURE: ê Be sure to insulate the discharge duct. ê Use canvas ducts with a metal framework on the inlet side. ê Consider the positioning of the suction and discharge grilles so as to prevent short-circuiting. ê Check the static pressure so the prescribed discharge air flow rate is being produced. ê Make it so the air filter is easy to remove when necessary.
Work procedure
Indoor unit installation
Indoor unit
Suspension bolt
Canvas duct Canvas duct
Air inlet/outlet installation Duct connection
– 28 –
2. Work by Process and Key Points (7) Insulation work
[Materials] For the insulation, use materials that can sufficiently withstand the temperature of the piping.
<Refrigerant piping>
� Heat-pump type…Heat resistant polyethylene foam (that can withstand temperatures over 120°C) � Cooling-only type…Polyethylene foam (that can withstand temperatures over 70°C)
<Drain piping> � Polyethylene foam (heat resistant temperature: –70 ~ 80°C)
ê If you assume that the temperature and humidity around the refrigerant pipe might exceed 30°C and RH80%, please use insulation with a thickness of 20 mm or more.
ê Polyethylene foam insulation material cannot be used in some areas (Hong Kong) due to the fire codes. Therefore, confirm this in advance.
ê Be sure to insulate connections (brazed, flared, etc.) after they have passed air tightness tests.
ê Be sure to i nsulate both the gas and liquid piping individually.
ê Be careful not to leave any gaps in the insulation joints. ê Be careful not to use damaged insulation material.
Work procedure
Refrigerant piping work
Insulation work (other than the connections)
Air tightness test
Insulation work (the
connections)
Drain piping work
Insulation work (other than the connections)
Drain flow test Insulation work
(the connections)
Gap in the insulation joint Damaged insulation material
Insulate both the gas and liquid piping together
Insulate the gas and liquid piping individually
Insulate only the gas piping
Liquid piping
Insulation material
Gas piping
Liquid piping
Insulation material
Gas piping
Insulation material
Gas piping
Liquid piping
Insulation material
~Working points~ Insulation work does not allow for checks/tests, so ensure that any maintenance and repair on the insulation joints and the like is done properly.
(7) Insulation work
– 29 –
Example of a polyvinyl tube being used
Suspension band with turnbuckle
Polyvinyl tube
¿ Indoor unit flares � Use the following guide to conduct insulation work properly up to the base of the refrigerant piping on the
indoor units.
(1) Wind the joint insulation material (accessory) around the flares on both the liquid and gas piping. � Always face the joint of the insulation material upward.
(2) Securely fasten both ends of the joint insulation material with the clamp material (accessory). (3) Wind sealer over the joint insulation material only for flares on the gas piping side. ê Be sure to always conduct the above work after the air tightness test.
¿ Supporting fixture insulation
� When supporting the horizontal piping, the weight of the piping tends to crush the insulation at the support spots and cause condensation. At support spots, either reinforce the insulation material using tape with insulating properties or provide support with a hard-type wide polyvinyl tube to spread the weight.
� Be careful not to wind any adhesive tape used for a temporary hol d too tightly.
¿ Reinforcement of the insulation material cuts � Insulation material shrinks with time, so it is recommended that the insulation material cuts be
reinforced with tape with insulation material after applying a special adhesive (Synthetic Rubber Based).
Flare insulation work guide Piping insulation
material (machine side)
Supporting fixture
Insulating reinforcement tape (5t × 50w)
Insulation material
(only gas piping side)
Tighten the section that overlaps with the piping
insulation material
Sealer (accessory)
Wind from the base of the machine to the upper portion of the flare nut connection Joint insulation material (accessory)
Flare nut connection Face the joint
upward
Piping insulation material
(locally procured)
Attach to the base
Clamp material (accessory)
(7) Insulation work
– 30 –
¿ When inserting the insulation material into a gap
� In consideration of possible shrinking of the insulation material in the future, insert insulation material that is 200 mm longer than the gap into the gap. The work that follows is the same as the above -mentioned (3).
¿ Reinforcement of insulation material at bends
� Try to minimize the number of cuts in the insulation material (one cut is ideal). � Consider where to cut the insulation material so that its reinforcement after bending can be
conducted at a straight pipe portion.
L + Approx. 200 mm of insulation material
Special adhesive
Reinforcement tape with insulation material
L
L+100
L
(7) Insulation work
– 31 –
2. Work by Process and Key Points (8) Control wiring work
ê If shielded wires are not properly grounded on one end, it can lead to communication problems. Therefore, when using a shielded wire, be sure to ground one end.
ê 1. Use wires of a thickness between 0.75 mm2 and 1.25 mm2.
<When using wires of other sizes> ¿ Thin type
When wiring over an extended distance, transmission may become unstable due to the drop in voltage. Moreover, it predisposes the wiring to noise effects. ¿ Thick type
When using daisy-chain wiring, 2 wires cannot be inserted into the indoor terminal block.
ê 2. Never use multi-core wiring (more than 2 cores).
In the case of a thick type 2 wires cannot be inserted into the terminal block
~Working points~ � Prepare a system diagram and check your work to prevent miswiring.
(8) Control wiring work
– 32 –
Indoor
Indoor
Normal condition (when sending)
Interference condition (when sending)
RC
RC 4-core cable (stray capacitance between cables )
<When using multi-core cables (more than 2 cores)> ¿ Signal interference occurs, resulting in transmission errors.
¿ The same thing that happens when using multi-core cables will occur when many single-core wires are inserted into the conduit.
ê 3. Never bind communication wires over an extended distance. <If communication wires are bound> ¿ The insulation distance between wires shortens, predisposing the wires to interference.
ê 4. Never wire with bound control wiring
<If control wires are bound> ¿ Strong and weak currents may mix together, so it is recommended not to use multi-core wires.
(It affects the wire withstanding voltage among other things.)
ê 5. Keep the control wiring and power wiring separate
<If the power wire and signal wire are laid parallel> ¿ Due to the influence of the electrostatic and electromagnetic coupling, a disturbing wave that interferes
with the signal wiring is induced, leading to malfunctions. ¿ When laying the signal wiring parallel to the power wiring, it is recommended to separate them with a
distance shown in the table below:
ê 6. Use the same type of wires for power wiring within the same system.
Power supply capacity for power wiring
Separation distance between power wiring and control wiring for
Daikin air conditioners
Separation distance between power wiring for other equipment and
control wiring for Daikin air conditioners
Less than 10A At least 300 mm
50A At least 500 mm
100A At least 1,000 mm
220V or more
More than 100A
At least 300 mm
At least 1,500 mm
Indoor unit
Indoor unit
RC
RC
[Poor example] [Good example]
Remote control PCB
Start/Stop (6-core wire)
Remote control PCB
Start/Stop
[When using multi-core cables: Example of the VRV series ]
– 33 –
2. Work by Process and Key Points (9) Outdoor unit installation
¿ Precautions when preparing foundations for outdoor units
· Support the unit with a foundation that is at least 66 mm wide
· When attaching the rubber cushion, attach it to the whole bearing face of the foundation
· The height of the foundation should be at least 150 mm from the floor
· Secure the unit to the foundation using the foundation bolts, nuts and washers (Use four sets of M12-type foundation bolts, nuts and washers)
· The optimum length of the foundation bolts from the surface of the foundation is 20 mm
· Make considerations for the drain outlet
· Pay attention to the floor strength and waterproofing when installing outdoor units on the roof.
Work procedure
Outdoor unit installation
Model A mm B mmRXYQ5P 635 497RXYQ8P
RXYQ10PRXYQ12P,14PRXYQ16P,18P
930 792
1240 1102Foundation drawing for outdoor unit
20
Foundation preparation
A
B
722~727 805
100
– 34 –
¿ Securing space for servicing/maintenance It is important to make considerations for space for servicing/maintenance.
ê Note that replacement of the compressor may become difficult depending on the piping route.
¿ Prevention of short-circuiting Short-circuiting can occur if the outdoor unit is not installed in a location with good ventilation.
ê Note that it may be necessary to install discharge ducts in cases as shown in the illustrations below:
<When installing under eaves> � N = M when L = 1 m.
� K = M when L < 1 m.
Note that Dimension K refers to the dimensions
necessary when installing a single unit.
Refer to 'Standards for installing
upward-discharging outdoor units' when
installing on each floor.
<If there are horizontal obstacles above> � No special measures are
required if L = 3 m.
� If L < 3 m, a discharge duct wi th
duct resistance of less than 8
mmH2O is necessary.
Dimension K for single unit
installation requires being
slightly larger.
For anything 8 HP or above, use of small concrete blocks at the four bottom corners of the outdoor unit as a foundation is not possible. However, this is possible with the 5 HP models.
Middle of the machine
Required for any machine of at least 8 HP
Middle of the machine
Required for any machine of at least 8 HP
Foundation
Not enough space for servicing/maintenance! (Impossible to remove the compressor.)
For short-circuiting
prevention
Discharge duct
Installing under eaves Measures for obstacles above
– 35 –
At le
ast 1
.5m
At le
ast 1
m
At le
ast 1
mAt least 1.5m
At least 1
m
At least 1.5m
At least 1.5m
¿ Considerations when installing inverter air conditioners Be sure to secure enough space for servicing/maintenance according to the instructions in the installation manual. ê Inverter air conditioners may induce noise from other electronic equipment. When selecting a location
for installation, maintain sufficient di stances from radios, PCs, stereos and the like in consideration of the installation of the air conditioner and power wiring.
Radios, PCs, stereos, etc.
Indoor unit
Indoor unit RC Cooling/ heating
changeover RC
Branching switch, overcurrent circuit breaker
Branching switch, overcurrent circuit breaker
– 36 –
4.0
3.5
2.0
1.5
1.0
0.5
0
4.0
3.5
2.0
1.5
1.0
0.5
0
2. Work by Process and Key Points (10) Air tightness tests
1) Evacuation of refrigerant piping <Work procedure>
• Connect the gauge manifold to the service ports on the liquid and gas piping. Operate the vacuum pump for about 30 minutes, though it may differ depending the respective piping length.
2) Nitrogen pressurization <Work procedure>
(1) Pressurize the liquid and gas piping for each refrigerant circuit according to the following steps: (Be sure to use nitrogen gas.) � Step 1: Pressurize at 0.3 MPaG(43.51 PSI) for approx. 3 minutes
� Step 2: Pressurize at 1.5 MPaG(217.55 PSI) for approx. 5 minutes
� Step 3: Pressurize at 4.0 MPaG(580 PSI) for roughly 24 hours
ê Even pressurized at 4.0 MPaG(580 PSI), a short time does not
allow for detection of smaller leaks. Be sure to pressurize for 24 hours in Step 3.
ê Never pressurize at a pressure above 4.0 MPaG(580 PSI) .
~Working points~ � Be sure to evacuate the piping before the air tightness test. � Be sure to always use nitrogen gas for the air tightness test. � The air tightness test pressure is the design pressure for air conditioners.
Work procedure
Completion of refrigerant piping
work
Nitrogen pressurization
Check for drop in pressure
Pass
Leak check
Evacuation
Example of the air tightness test
Allows for detection of large leaks
Allows for detection of smaller leaks
[Time chart] Step3
If no pressure drop, PASS
Step1
3 minutes 5 minutes Time
24 hours
Pressure
MPaG
Step2
(10) Air tightness tests
– 37 –
3) Check for pressure drop ¿ If there is no pressure drop, it has passed the test.
Any differences in ambient temperature between during pressurization and during check for pressure drops will necessitate correction because pressure changes by roughly 0.01 MPaG per 1°C. Correction value: (Temperature during pressurization – Temperature during check) x 0.01 MPaG (Example)
Pressure used for pressurization Ambient temperature Pressurization 4.00MPaG 25°C
24 hours later 3.95MPaG 20°C
In this case, the correction would be 0.05 MPaG so you can determine there has been no pressure drop (indicating a PASS).
4) Leak check
� If a drop in pressure has been detected, search for the leak site by applying soapy water to the surface of the piping connections (flares, brazed spots) and charge the hose connections.
� It is rare to conduct an air tightness test on everything from the outdoor unit to indoor unit at the same time. If a pressure drop has been detected, it takes a lot of time to check where the leak is. An efficient method to check is on a block-by-block basis in accordance with the work schedule.
� After conducting the air tightness test, leaving the pressure between 0.2 and 0.3 MPaG in the piping allows for the prevention of contamination in the piping.
� The work can be conducted efficiently if the pressurization assembly
is prepared beforehand.
(1)
(3)
(2)
Shaft
<Air tightness tests by the block> (1) For each floor, check from the indoor unit to the
vertical pipe within each shaft. (2) Check the above (1) and the vertical piping within
each shaft. (3) Check all piping from the indoor unit to the vertical
piping to the outdoor unit.
(10) Air tightness tests
– 38 –
2. Work by Process and Key Points (11) Vacuum drying
~What is vacuum drying?~ Using a vacuum pump, the moisture (liquid) in the piping is changed to vapor (gas) and expelled out of the piping in order to dry the inside of the piping. At 1 atmospheric pressure (101.3 kPa or 760 mmHg), the boiling point (evaporation temperature) for water is 100°C. However, the closer the pressure within the piping comes to reaching a vacuum state as a result of using the vacuum pump, the lower the boiling point becomes. Once the boiling point falls below the outdoor temperature, the water will evaporate.
<Example> If the outdoor air temperature is 7.2°C, vacuum drying cannot be conducted unless the pressure is lowered below −100.3 kPaG (−752mmHg). Therefore, when conducting vacuum drying, 'selection and maintenance of the vacuum pump ' is important.
¿ Selection of the vacuum pump
Note the following two points when selecting a vacuum pump.
1. Select one that allows for pressure to be brought below –100.7 kPaG (−755 mmHG).
2. Select one that allows for relatively high discharge volume. (One with at least 40 L/min. is recommended.) � Before conducting the vacuum drying work, be sure to check with a vacuum gauge that the
pressure reaches a level below −100.7 kPaG(-14.605 PSI) .
ê Use s pecial tools for R410A (e.g., gauge manifold, charge hose). Reasons: Refrigerant oils differ between R410A and R22. Using different tools will result in
refrigerant oils being mixed between the two, which will result in the development of impurities and the clogging of the refrigerant circuit.
Water boiling point Absolute pressure Gauge pressure
kPa mmHgG mmHg kPaG
After passing air tightness test
Vacuum drying
Vacuum test Work
procedure
Necessary degree of vacuum
Outdoor temperature range
Evaporating point
Temperature (°C)
Gau
ge p
ress
ure
kPaG
(mm
Hg)
Abs
olut
e pr
essu
re k
Pa
(mm
Hg)
?
– 39 –
<Work procedure>
There are two methods of vacuum drying depending on the onsite conditions so selectively use them. 1) Normal vacuum drying…This is the common method.
(1) Vacuum drying (1st time) � Connect a gauge manifold to the service ports of the liquid and gas piping and operate the vacuum
pump for at least 2 hours. (The pressure must be below −100.7 kPaG or −755 mmHg.) � If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 2 hours, there
may either be moisture or a leak in the circuit. Vacuum for 1 more hour to confirm this . � If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 3 hours,
check for the leak site. (2) Vacuum test
Leave the system in a vacuum state below −100.7 kPaG or −755 mmHg for at least 1 hour and confirm that the gauge indicator does not rise.
ê Conduct evacuation from both the liquid and gas piping. There are various types of functioning
components in an indoor unit and evacuating only from one (liquid or gas) piping may result in a break in the vacuum state.
� If the gauge indicator rises, there may be moisture remaining or a leak in the circuit.
– 40 –
Additional refrigerant charge
Vacuum state (1 hour)
Vacuum drying (1 hour)
Vacuum break
Vacuum drying (2 hours)
2) Special vacuum drying Special vacuum drying is conducted when there is a risk of moisture within the piping. For example, � When work has been done during the rainy season and there is a risk of condensation within the piping � When the work has taken a long time and there is a risk of condensation within the piping � When there is a risk that rain has entered into the piping during work
The special vacuum drying incorporates at least one vacuum break process using nitrogen gas during the normal vacuum drying process.
(1) Vacuum drying (1st time) � Connect a gauge manifold to the service ports of the liquid and gas piping and operate the vacuum
pump for at least 2 hours. (The pressure must be below −100.7 kPaG or −755 mmHg.) � If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 2 hours, there
may either be moisture or a leak in the line. Vacuum for 1 more hour to confirm this . � If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 3 hours,
check for a leak site. (2) Vacuum break (1st time)
Pressurize with nitrogen to 0.05 M PaG. (The nitrogen gas is a dry nitrogen, so breaking the vacuum state with it increases the effectiveness of the vacuum drying.)
(3) Vacuum drying (2nd time) Operate the vacuum pump for at least 1 hour. Determinations: The pressure must reach at least −100.7 kPaG or −755 mmHg. If it does not even after 2 hours of operation, repeat steps (2) (vacuum break) and (3) (vacuum drying).
(4) Vacuum test Leave the system in a vacuum state below −100.7 kPaG or −755 mmHg for at least 1 hour and confirm that the gauge indicator does not rise. If the gauge indicator rises, there may be moisture remaining or a leak in the circuit.
ê Be sure to use nitrogen gas when conducting vacuum break.
[Special vacuum drying time chart]
Pressurized side
Vacuumed side
Atmospheric pressure
+0.05 MPaG
0 MPaG
-26.7 kPaG
-53.3 kPaG
-80.0 kPaG
-93.3 kPaG -101.3 kPaG
-100.7 kPaG
-100.7 kPaG
– 41 –
2. Work by Process and Key Points (12) Additional refrigerant charge
<Work procedure> (1) Calculation of the additional refrigerant charge amount � Accurately assess the length of the refrigerant piping to calculate the amount of additional refrigerant charge.
(For calculating the formula, refer to the equipment design materials for the respective models.)
ê Be sure to enter the calculated additional refrigerant charge amount on the 'additional refrigerant charge instruction label' on the outdoor unit. (The data will be needed for maintenance.)
(2) After completing the vacuum drying, leave the air conditioner OFF, open Valve A and charge the calculated additional refrigerant from the cylinder via the liquid side stop valve service port using pressure difference.
ê Be sure to charge the refrigerant in a liquid state. (Cylinders with siphons allow for charging of liquid refrigerant in a standing position.)
ê Use a digital scale to measure. If the refrigerant cannot be charged due to pressure equalization,
(3) Close Valve A and then open Valve B. (4) Turn on the outdoor and indoor unit power supplies. (5) Completely open up the gas and liquid side stop valves.
ê Be sure to charge refrigerant from the refrigerant charge port.
(6) Turn the additional refrigerant charge operation to ON using the setting mode while leaving the air conditioner OFF. ê Refer to the 'Service Precautions' label on the outdoor unit's electrical box cover for the
procedures regarding additional refrigerant charge operation.
(7) Once the required volume of refrigerant has been charged, push the mode button (BS1) on the PCB (A1P) to
stop the operation.
Work procedure Additional
refrigerant charge
Calculation of additional refrigerant charge amount
based on piping length
Indoor unit
Gas side stop valve
Outdoor unit
Liquid side stop valve
Refrigerant cylinder with
siphon
Cylinder
Gauge
Gauge manifold
Valve B
Valve A
Refrigerant charge port
After completion of vacuum drying
– 42 –
Technical Question & Answer Quest. 1) Why centre support is required for 8 HP and 18 HP. However 8 HP ODU has no heavy material in side? Please give a clear reason.
Ans: 1) The Supports required on three locations (both ends and middle) for 8 HP or more. Reason: To prevent sagging of casing. Incase of both side supports only, after long time nock frame and ODU leg may bend due to the compressor weight, so, inside parts may incline one side and may bulge (cramp) the adjacent plate. Small Casing is examined and confirmed that only two supports are sufficient at either ends. VRV III casing type is as follows: A) Small casing < Product width: 635mm> (VRVIII5-6HP) . . . ? B) Middle casing < Product width: 930mm> (VRVIII8-10HP) . . . × C) Large casing < Product width: 1240mm> (VRVIII12-18HP) . . . × About the selection of Pipe size: Quest. 2. If maximum length after first Refnet is >40M (i.e 90M) where all the pipe size has to be changed? Ans.2. If the pipe line exceed in circuit B then only in circuit B pipe size to be increased for 90M condition and not in circuit A. (Reference Topic & Page of ED 34-645B Sl. No. 6.5 Page 657/658).
ODU
IDU
IDU
IDU
IDU Circuit B
NNoottee
TCDB001
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