6 Optional functions
Complementary systems
SMGB0099 rev.0 - 12/2016
230
• By the duty signal.
For systems controlled by a duty signal it is possible to force the thermo-Off by the duty signal itself. When the duty
signal becomes the minimum of its range (0 V or 4 mA) the system will be switched to thermo-Off condition. To be
switched to thermo-On condition the duty must become higher than the 8% of its range.
Setting note: No additional setting is required once the demand control setting has been set as Duty control.
Type
Description
Standard thermo-On / thermo-Off control
(Default setting)
Suitable for installations controlled by suction or discharge temperature.
The thermo-ON / thermo-OFF logic is decided based on the difference between
the inlet temperature to the coil and the set temperature on the remote controller or
central controller.
By an external input
The thermo-On / thermo-Off control can be driven externally by an input signal
connected to the CN3 socket of the PCB1 of the DX-Kit.
Setting note: DIP Switch 1 – Pin 6 of DX-Kit PCB2 (small PCB) must be switched on
(PCB2- DSW1#6 switched ON). Once the PCB DSW has been set, the input “i1” of
CN3 is automatically set for thermo-On / thermo-Off control. The setting of input “i2” is
kept as set on the remote controller.
Please refer to HITACHI Indoor Units Service Manual for further information about the
setting and connection of the auxiliary inputs to CN3 socket.
By the duty signal
For systems controlled by a duty signal it is possible to force the thermo-OFF by the
duty signal itself. When the duty signal becomes the minimum of its range (0V or
4mA) the system will be switched to thermo-OFF condition. To be switched to thermo-
ON condition the duty must become higher than the 8% of its range.
Setting note: No additional setting is required once the demand control setting has
been set as Duty control.
6.3.2
Econofresh Kit
Available ports
The system has three optional input signals programmed into the PCB using connector CN3 on the RPI unit and using
the remote control. Connector CN3 has two ports for configuring the optional input signals of the Econofresh kit.
The outdoor cooling function E1 requires no CN3 connector setting.
?
N O T E
When the RPI unit DSW6 is set for use of the Econofresh kit, CN3 connectors 1 and 2 are locked on the RPI unit PCB.
Description of optional input signals
Enthalpy sensor
On-screen display:
E2
.
The signal opens and closes the air inlet valves and the outlet damper, mixing the outdoor air and the return air of the
Econofresh kit. This function is based on the air quality parameters that provide precise control of the air quality.
Connect the cables as indicated in point
. Only CN3 contacts 1 and 2 can be connected.
The signal has the following control logic:
Connector
Contact number
X1
Damper valve
CN3
1, 2
ON
—
OFF
Enabled
