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4. Water piping work
4.1. Water piping connection (Fig. 4-1)
• Connect the water pipes to the outlet and inlet pipes.
(Parallel male screw for 1-inch water pipe (ISO 228/1-G1B))
• Inlet and outlet pipes position is shown on the Fig. 4-1.
• Install the hydraulic filter at the water intake.
• Maximum allowable torque at the water piping connection is 50 N•m.
• Check if water leaks after installation.
• Inlet water gauge pressure must be between 0-0.3 MPa.
• Use the inlet water with a temperature lower than 55 ˚C.
Note:
Refer to the indoor unit installation manual.
• The water velocity in pipes should be kept within certain limits of material
to avoid erosion, corrosion and excessive noise generation.
Be aware, and take care of, that local velocities in small pipes, bends and
similar obstructions can exceed the values above.
• When connecting metal pipes made of different materials, be sure to insu
-
late the joint to prevent electrolytic etching.
• Set up a field system so that the inlet water temperature and water flow
rate can be within the allowable range specified in our technical data, etc.
If the unit is used out of the allowable range, the parts of unit might be
damaged.
Fig. 4-2
Parts
Check every
Possible failures
Pressure relief valve
(3 bar)
1 year
(pushing the lever manu-
ally)
PRV would be fixed and
expansion vessel would
burst
Lever
Water outlet
Caution:
• Operate the lever when the water temperature falls below 40°C.
• Check that the water outlet of the pressure relief valve is facing downward
before operating the lever.
If it is not facing downward, rotate the PRV so that it is facing downward.
A
B
Note:
Make sure to perform the frozen prevention measure for water pipe system.
(Water piping insulation, back-up pump system, using of a certain % ethylene
glycol instead of normal water)
Insulate the water piping properly. The performance can be poor if the insula
-
tion is insufficient.
Warning:
As the outlet water temperature can reach 60 ºC at maximum, do not touch the
water piping directly with a bare hand.
Fig. 4-1
4.2. Water quality condition
• The water in a system should be clean and with a pH value of 6.5-8.0.
• The followings are the maximum values;
Calcium : 100 mg/L
Chlorine : 100 mg/L
Ca hardness : 250 mg/L
Copper : 0.3 mg/L
[Fig. 4-1]
A
Water outlet
B
Water inlet
4.3. Minimum water quantity
Refer to the indoor unit installation manual.
4.4. Parts which require regular inspection (Fig. 4-2)
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