Hitachi YUTAKI S COMBI Series Instruction Manual page 40

UNIT INSTALLATION
6.3.3 Drain pipes connection
For a correct drainage, connect the drain pipe for the safety
valve (located at the top rear side of the unit) to the general
draining system.
P&T relief valve
(Only for UK market)
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N O T E
• The safety valve is activated when water pressure reaches 3 bars.
• Drain taps must be provided at all low points of the installation to
permit complete drainage of the circuit during servicing.
• P&T relief valve is activated when water pressure reaches 7 bar and/
or water temperature reaches 96ºC
• Discharge pipe must be made of metal or any other material capable
to withstand the high pressure and high temperature from the P&T
relief valve.
• For a correct installation and workpipe of the discharge pipe on UK
market models, refer to UK Building Requirements
6.3.4 Refrigerant piping connection
Make the connection of refrigerant pipes respecting the
considerations indicated in the CD-ROM factory-supplied with
the unit. The refrigerant piping connections are flare nut.
6.3.5 Power and transmission wiring
connection
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Safety instructions
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N O T E
Check the requirements and recommendations in the chapter
and control settings".
!
D A N G E R
• Do not connect the power supply to the indoor unit prior to filling
the space heating and DHW circuits with water and checking
water pressure and the total absence of any water leakage.
• Do not connect or adjust any wiring or connections unless the
main power switch is OFF.
• When using more than one power source, check and ensure that
all of them are turned OFF before operating the indoor unit.
• Avoid wiring installation in contact with the refrigerant pipes,
water pipes, edges of plates and electrical components inside
the unit to prevent damage, which may cause electric shock or
short circuit.
!
C A U T I O N
• Use a dedicated power circuit for the indoor unit. Do not use a power
circuit shared with the outdoor unit or any other appliance.
22 PMML0573 rev.1 - 07/2021
•
•
Safety valve
•
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Access to the electrical box before performing the next steps:
1 Using the appropriate cable, connect the power circuit to the
"5 Electrical
2 Connect the transmission wires between outdoor and indoor
3 Carry out the necessary electrical connections of the
Make sure that all wiring and protection devices are properly selected,
connected, identified and fixed to the correspond ing terminals of
the unit, specially the protection (earth) and power wiring, taking
into account the applicable national and local regulations. Establish
proper earthing; Incomplete earthing may cause electrical shock.
Protect the indoor unit against the entry of small animals (like rodents)
which could damage the drain pipe and any internal wire or any other
electrical part, leading to electric shock or short-circuit.
Keep a distance between each wiring terminal and attach insulation
tape or sleeve as shown in the figure.
Tape or sleeve
Connection procedure
appropriate terminals as shown on the wiring label and the
illustration below. Connect the power supply cables to the
terminal board (TB1) , and the earth conductor to the earth
screw in the electrical box plate.
TERMINAL BOARD 1 (TB1)
Power terminals
Power terminals
Case 1. Power supply:
1~ 230V 50Hz
unit to the terminals 1 and 2 on the terminal board 2 (TB2).
1 2
1 2
optional accessories using the terminal board 2 (TB2).
Consult its label for a better understanding.
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N O T E
Refer to the section "5.5 Optional indoor unit wiring
Earth terminal
Case 2. Power supply:
3N~ 400V 50Hz
Indoor unit
Outdoor unit
(accessories)".