Hitachi YUTAMPO Serie Installations- Und Betriebshandbuch Seite 13

UNIT INSTALLATION
• The recommended standard water quality for the DHW circuit is shown
in the table below.
Item
Electrical conductivity (mS/m)
(25 °C)
Chlorine Ion (mg CI¯/I)
Sulphate (mg/l)
Combination of chloride and
sulphate (mg/l)
Total Hardness (mg CaCO /I)
3
?
N O T E
• (1): The " " mark in the table indicates that the concerned item is a
factor increasing the tendency of each of the phenomena.
• (2): Water quality must comply with EU directive 98/83 EC.
5.3.5 Refrigerant piping connection
The connection of refrigerant pipes must be done respecting the
considerations indicated in the Installation Manual of the outdoor
unit. Flare nuts are used for the connection of refrigerant piping.
Follow the instruction "1) Preparation of Pipe" as indicated in the
Installation Manual of the outdoor unit.
1 Use the flare nuts supplied in the accessory bag.
2 Please be careful when bending the copper pipe.
3 Place the flare nuts manually to avoid misalignment. Once
the flare nuts have been screwed in, use a torque wrench to
tighten the connection.
Fix wrench
Screw
wrench
?
N O T E
Do not perform connection work with only one wrench. Always use two
wrenches (keeping one of them fixed, while using the other to tighten the
connection). Refrigerant leakage may occur if the screwing procedure is
performed with only one wrench.
4 After having performed the connection of refrigerant piping,
seal the open space between the knock-out hole and
refrigerant pipes with insulation material.
5 Follow the instruction "3) Remove air from the Pipe and gas
leakage inspection" as indicated in the installation manual of
the outdoor units.
7 PMML0451 rev.2 - 03/2018
DHW space Tendency
(1)
Water Deposit
Corrosion
supply of scales
(2)
100~2000
max 250
max 250
max 300
60~150
Outer
Torque
diameter
N.m
of pipe
(kgf.cm)
(Ø)
Small
13.7-18.6
diameter 6.35 (1/4")
(140-190)
side
Large
34.3-44.1
diameter 9.52 (3/8")
(350-450)
side
!
C A U T I O N
• Check for refrigerant leakage in detail. If a large refrigerant leakage
occurred, it would cause difficulty with breathing. Also, harmful gases
would be generated if there was a fire in the room.
• If the flare nut is tightened too hard, it may crack over time and cause
refrigerant leakage.

Maximum permitted concentration of HFCs
The R410A refrigerant (charged in the outdoor unit) is a non-
flammable, non-toxic gas. However, if leakage occurs and the
room becomes filled with gas, it may cause suffocation. The
maximum permissible concentration of HFC gas according to
EN378-1 is 0.44 kg/m , and the volume of the installation room
3
must be greater than 3.2 m
3
of leakage.
The formula used for the calculation of the maximum refrigerant
concentration allowed in case of refrigerant leakage is the
following:
R R: Total quantity of refrigerant charged (kg)
— = C V: Volume of the room (m³)
V C: Refrigerant concentration
If the volume of the room does not meet this minimum value,
some effective measures must be carried out after installation to
prevent suffocation in case of leakage.
in order to avoid suffocation in case