Hitachi YUTAKI S80 Series - Space Heating Hydraulic Circuit; Hydraulic Circuit

9. Refrigerant and water piping
TCGB0075 rev.0 - 11/2012
103
9
9.2 Space heating hydraulic circuit
D A N G E R
DonotconnectthepowersupplytotheindoorunitandDHWtankpriorllingofwaterbothcircuitsandchec-
king water pressure and the total absence of any water leak.
N O T E
The maximum piping length depends on the maximum pressure availability in the water outlet pipe. Please
check the pump curves.
9.2.1 Hydraulic circuit
Water ow Flare Nut connection Brazed connection
Union Nut
Nature No. Part name
Factory
supplied
1 Plate heat exchanger (R134a-H2O)
2 Air purger
3 Indoor unit manometer
4 Water pressure switch
5 Expansion vessel
6 Water pump
7 Water outlet thermistor
8 Water ow switch
9 3-way valve
10 T-branch
11 Water pressure port (G 3/8”)
12 Water inlet thermistor
13 Water strainer
14 Safety valve
15 Draining
16 Plate heat exchanger (R410A-H2O)
17
Space heating inlet water pipe (1”)
(accessory)
18
Space heating outlet water pipe (1”)
(accessory)
Field
supplied
19 Shut-off valve (eld supplied)
Accessory 20
Water check valve
(ATW-WCV-01 accessory)
Indoor unit hydraulic circuit
Field installation
Space heating
Field
water
circuit
Water inlet
connection (1”)
Water outlet
connection (1”)

Additional hydraulic necessary elements
The following hydraulic elements are necessary to correctly perform the space heating water circuit:
• 2 shut-off valves (eld supplied) must be installed in the indoor unit. One at the water inlet connection and the other at
the water outlet connection in order to make easier any maintenance work.
• 1 water check valve (ATW-WCV-01 accessory) with 1 shut-off valve (eld supplied) must be connected to the water
lling point when lling the indoor unit. The Check valve acts as a safety device to protect the installation against back
pressure, back ow and back syphon of non-potable water into drinking water supply net.
N O T E
Anadditionalspecialwaterlterishighlyrecommendedtobeinstalledonthespaceheating(eldinstallation),
inordertoremovepossibleparticlesremainingfrombrazingwhichcannotberemovedbytheindoorunitwater
strainer.