Hitachi YUTAKI Series Installation And Operation Manual page 117

UNIT CONTROLLER
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DHW optional functions
DHW Boost:
To force a one-time heating of the DHW tank up to
the temperature set as DHW Boost temperature.
This feature is useful to cover exceptional demand
of DHW.
• Trigger type: Push (favourite button), Open (NC)
or Closed (NO). Set input 6 for DHW Boost (for
trigger type open/closed). (see section
Inputs, Outputs and Sensors configuration")
• Boost setting: DHW temperature setting for the
Boost function.
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Emergency Operation
Mode:
Selection of the emergency operation mode:
• Manual: Emergency operation is active when
is manually enabled (by DSW4 pin 4 ON).
The emergency mode uses the heater (space
heating or DHW) to provide the required heating.
• Automatic: Emergency mode operates when
there is an event of outdoor unit failure and
Demand ON of space heating (enabled) or DHW
(enabled).
107 PMML0510 rev.1 - 10/2019
"7.8.2.10
Circuit Pump: By using this output, user
can heat all the water inside DHW piping
system. Output must be configured at
the I/O and sensors menu. (see section
"7.8.2.10 Inputs, Outputs and Sensors
configuration")
• Disabled.
• Demand: Enable DHW recirculation.
• Anti Legionella: Allows
recirculation while anti legionella is
active.
• Timer: A timer can be programmed
in order to start or stop the water
recirculation.
Recirculation timer:
• Frequency: Allows to select when
timer is applied (Everyday, weekend,
workday)
• Starting Time: When the water pump
circulation starts.
• Stopping Time: When the water pump
circulation stops.
• Operation: In case of ON, means that
water pump is always ON between
"Starting Time" and "Stopping Time".
In case it is set to Timer, Recirculation
pump is ON during "ON Time" after
being OFF during "OFF Time" within
Starting Time and Stopping Time.
• ON Time: On time period of
Recirculation pump.
• OFF Time: Off time period of
Recirculation pump.
Space Heating:
Enable or disable emergency operation
for space heating.
Only available in case "Heating source"
on "7.8.2.7 Complementary Heating
configuration" contains "Electrical
heater or boiler" option
DHW:
Enable or disable emergency
operation for DHW. Only available
when electrical heater for DHW is
enabled (by DSW).
DHW