Hitachi YUTAKI S Series Technical Catalogue page 134

10 Optional functions
Indoor unit
10.1.2 Optional functions by Unit controller (PC-ARFH1E)
10.1.2.1 Optional functions for Space Heating or Space Cooling
Optional function
Floor screed drying function
(Circuits 1 & 2)
Heating Auto ON/OFF
Auto Heat-Cool
Outdoor temperature average
timer
10.1.2.2 Optional functions for DHW
Optional function
DHW anti-Legionella
protection
DHW re-circulation
DHW boost
DHW Mode
DHW Control
126 TCGB0123 rev.2 - 10/2019
This function is used exclusively for the process of drying screed that has been newly
applied to floor heating system.
The water temperature set-point follows a predetermined schedule upon activation of the
floor screed drying function.
For more information refer to Water control chapter
At higher outside temperatures it doesn't make sense to keep heating the building. The
YUTAKI S System will switch the heating off when the daily average outdoor temperature
of previously day rises above the Summer Switch Auto On/Off Activation Temperature.
For more information refer to "Space water temperature control"
Manual.
Only available for Cooling and Heating models and cooling mode enabled.
By using auto summer switch off average, user can use auto heat cool mode.
The end-user sets the desired operation mode on the user interface: Heating, Cooling or
Automatic. When Automatic is selected, the change of the operation mode is based on:
Averaged outdoor temperature: the operation mode will be changed in order to always
be within range determined by the space heating OFF temperature for heating and
the space cooling ON temperature for cooling. If the outdoor temperature drops, the
operation mode switches to heating and vice versa.
For more information refer to "Space water temperature control"
Manual.
The average timer corrects the influence of ambient temperature variations. The
weather-dependent set point calculation is done on the average outdoor temperature.
The outdoor temperature is averaged over the selected time period.
For more information refer to
"Space water temperature control"
Manual.
A specific setting is available to protect the DHW system against Legionella, which raises
up the DHW temperature over the normal DHW tank temperature setting (using the
electric heater of the DHW tank and/or the heat pump) on a periodic basis.
For more information refer to "Sanitary Water Operation"
This function allows the activation of the water pump for the re-circulation of the hot
water from the DHW tank by means of the heat pump.
This function can also be used with the anti-legionella protection function.
For more information refer to "Sanitary Water Operation"
With this function enabled, it is possible to request a heating up of the DHW when user
requires an instantaneous delivery of DHW.
For more information refer to "Sanitary Water Operation"
DHW operation has two different modes, STANDARD Mode and HIGH DEMAND Mode:
• STANDARD Mode: The heating of the domestic hot water shall be started when
water temperature in tank is low enough for Heat Pump to be started. DHW is always
started heated by Heat Pump.
• HIGH DEMAND Mode: The heating of the domestic hot water is started if differential
is bigger than T . It will be started with water tank heater only unless water
DHWON
temperature in tank goes below Heat Pump starting temperature.
For more information refer to "Sanitary Water Operation"
Unit has 2 DHW heating up control modes that are selected by PC-ARFH1E:
H.EFFICIENCY MODE: Control to keep best efficiency (COP).
H.SPEED MODE: Control to heat tank as fast as possible.
Explanation
chapter in Service
chapter in Service
chapter in Service
Explanation
chapter in Service Manual.
chapter in Service Manual.
chapter in Service Manual.
chapter in Service Manual.
Model
A
A
S/SC/M/
YCC
A
Model
A
A
A
A
A