12 Optional functions
TCGB0070 rev.3 - 04/2012
160
12.1 Optional functions of the indoor unit
Optional function
Explanation
From LCD user
’s interface
Floor screed drying function (Circuits 1 & 2)
This function is used exclusively for the process of drying screed that has been
newly applied to floor heating system.
When the user activates the floor screed drying function, the water temperature
set-point will follow a predetermined schedule.
Automatic summer switch-OFF
The system will switch OFF the heating mode when the daily average outdoor
temperature of previous day rises above certain value at the summer switch-
OFF activation temperature, avoiding to provide heating at high outdoor tempe-
ratures.
Pump and motorized valve seizure protection
This function prevents the components of being sticked during long periods of
inactivity by running every week the components during a short period.
DHW anti-Legionella protection
In order to help protect against Legionella into the DHW system, it is available
an specific setting which will raise up the DHW periodically (by the DHW tank
electric heater or by a boiler) over the normal DHW tank temperature setting.
Electrical tariff input
This function allows an external tariff switch device to switch OFF the heat
pump during peak electricity demand period. Depending on the setting, the heat
pump or DHWT will be blocked when signal is open/closed.
Hydraulic separator combination
When the indoor unit’s water pump is not sized for heating installation (small
water pump) or when the system is configured to alternate when a boiler, an
hydraulic separator or buffer tank must be used to ensure proper hydraulic
balancing.
In this case, the hydraulic separator option can be enabled by the LCD user’s
interface.
From dip-switch setting
Electrical heater or boiler emergency mode
In the event of outdoor unit failure, the required heating can be provided by the
electric heater or by the boiler, by means of a dip-switch setting.
One step heater for three phase imbalance
option
In order to prevent 3-phase imbalance by the electric heater steps, this option
can be used to switch all 3 steps at the same time, by means of a dip-switch
setting.
N O T E
This function only applies when power source of the indoor unit
is 3-phase (3N~ 400V 50Hz).
2nd. outdoor temperature sensor accessory
In situations where the outdoor unit is installed into a location where its own out-
door ambient temperature sensor can not give a suitable temperature measure-
ment to the system, it is available the 2nd. outdoor ambient temperature sensor.
In this case, it is necessary a dip-switch setting to use this temperature value
instead of the outdoor ambient temperature value.
.
Available four external outputs signals
There are available four output optional signals that provide four optional
functions of the system, programmed on the indoor unit PCB.
N O T E
In order to make easy the electrical connection works, HITACHI
offers (as accessory) a relay board for the additional output sig
-
nals.
N O T E
For the detailed information about the Optional functions of the indoor units, please refer to the Service Manual
(SMXX0070).
