Water Piping Work - Mitsubishi Electric PUZ-WM . AA serie Installationshandbuch

6. Water piping work

6.1. Water piping connection (Fig. 6-1)
• 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. 6-1.
• 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:
• The water velocity in pipes should be kept within certain limits of ma-
terial 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.
e.g.) Copper : 1.5 m/s
• 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 dam-
aged.
6.2. 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
Iron/manganese : 0.5 mg/L
[Fig. 6-1]
A Water outlet
B Water inlet
6.3. Minimum water quantity
Refer to the indoor unit installation manual.
A
B
Fig. 6-1
Note: Make sure to perform the frozen prevention measure for water pipe sys-
tem. (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
insulation is insufficient.
WARNING:
As the outlet water temperature can reach 60 ºC at maxi-
mum, do not touch the water piping directly with a bare
hand.
Note:
Parts which require regular inspection
Parts Check every
Pressure relief valve (3bar) 1 year
Temperature and pressure (turning the knob
relief valve manually)
en
Possible failures
PRV would be fixed and
expansion vessel would
burst
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