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4.2. Refrigerant piping work
After connecting the refrigerant pipes of the outdoor units with the outdoor units’ stop
valves remained fully closed, evacuate vacuum from the outdoor units’ stop valve
service ports.
After completing the above, open the outdoor units’ stop valves. This connects the
refrigerant circuit (between outdoor and hydro unit) completely.
How to handle stop valves is described on each outdoor unit.
Notes:
•
Have a fire extinguisher nearby before brazing work.
•
Provide no-smoking signs at the brazing workplace.
•
After pipe connection, be sure to check that there is no gas leakage, using
a leak detector or soap-and-water solution.
•
Before brazing the refrigerant piping,
always wrap the piping on the main
body, and the thermal insulation piping, with damp cloths to prevent heat
shrinkage and burning the thermal insulation tubing.
Take care to ensure
that the flame does not come into contact with the main body itself.
•
Do not use leak-detection additives.
•
Straight run of pipe connecting twinning pipe is 500 mm or more.
•
Piping work shall be kept to a minimum.
•
The pipes shall be protected from physical damage.
Warning:
Do not mix anything other than the specified refrigerant (R32) into the
refrigerating cycle when installing or moving. Mixing air may cause the
refrigerating cycle to reach abnormally high temperature, resulting in burst
pipes.
Caution:
Cut the tip of the outdoor unit piping, remove the gas, and then remove the
brazed cap.
4.3. Insulating pipes
Be sure to add insulation work to piping by covering high-temperature pipe and low-
temperature pipe separately with enough thickness heat-resistant polyethylene
foam, so that no gap is observed in the joint between the hydro unit and insulating
material, and insulating materials themselves. When insulation work is insufficient,
there is a possibility of condensation. Pay special attention to insulation work in the
ceiling plenum.
[Fig. 4.3.1] (P.4)
* If a polyethylene cover is used as an outer covering, asphalt roofing is not
necessary.
•
Insulation materials for the pipes to be added on site must meet the following
specifications:
•
Installation of pipes in a high-temperature high-humidity environment, such as
the top floor of a building, may require the use of insulation materials thicker than
the ones specified in the chart above.
•
When certain specifications presented by the client must be met, ensure that
they also meet the specifications on the chart above.
•
The brazed connections must be covered with insulation, with its seam facing
upward and fastened with the bands.
4.4. Drain piping work
Drain or condensation water will be discharged from hydro units during test run. If
this will be a problem, install a separately sold drain pan, following the procedures
explained below for connecting drain piping.
1. Drain piping work
•
Ensure that the drain piping is downward (sloped gradient of more than 1/100) to
the outdoor (discharge) side. If it is impossible to take any downward pitch, use
an optionally available drain-up mechanism to obtain a downward pitch of more
than 1/100.
•
Ensure that any cross-wise drain piping is less than 20 m. If the drain piping is
long, support it with metal brackets to prevent it from bending, warping, or
vibrating.
•
Ensure that collected pipes are 10 cm lower than the unit body’s drain port as
shown in
2
.
•
Do not put the end of the drain piping in any drain where ionic gases are
generated. (Drain pan: optional parts)
•
Do not use any odor trap around the discharge port.
[Fig. 4.4.1] (P.4)
•
Set the end of drain piping in a place without any risk of odor generation.
•
Drain piping may be installed in any direction. However, please be sure to
observe the above instructions.
2. Discharge test
After completing drain piping work, test drain discharge using a small amount of
water. Also, check to see that there is no water leakage from the connections.
3. Insulating drain pipes
Provide sufficient insulation to the drain pipes just as for refrigerant pipes.
Caution:
Be sure to provide drain piping with heat insulation in order to prevent excess
condensation. Without drain piping, water may leak from the unit causing
damage to your property.
A
Steel wire
B
pipe
C
Oily mastic asphalt or asphalt
D
Insulation material A
E
Outer covering B
Insulation
material A
Glass fiber + Steel wire
Ad Heat-resistant polyethylene foam + Adhesive tape
Outer
covering B
Indoor
Vinyl tape
Under the floor and exposed
Waterproof hemp cloth + Bronze asphalt
Outdoor
Waterproof hemp cloth + Zinc plate + Oily paint
Outdoor unit
High-pressure pipe
10 mm or more
-Hydro unit Low-pressure pipe
20 mm or more
Temperature Resistance
100°C min.
A
Downward slope 1/100 or more
B
Drain hose
C
Unit
D
Collective piping
E
Maximize this length to approx. 10 cm
* A drain pan is separately sold (for indoor use only).
WT09052X01_en.book 12 ページ ２０１９年１月１７日 木曜日 午前１０時４９分
