Hitachi RAS-4-HNCE - Description of Optional Signals

6. Optional functions
151
SMGB0079 rev.0 - 01/2013
6
6.1.4 Description of optional signals

Input signals
RAS-(2-2.5)HVNP / RAS-3HVNC
1 Fixing operation mode (heating / cooling)(1/2)
This input function is xed in terminals CN1 or CN2 of the PCB of the outdoor unit, to use it as a cooling and heating mode.
CN1 must be set up as follows.
Short circuit between the terminals 1 and 2 of CN1: set heating mode.
Short circuit between the terminals 2 and 3 of CN1: set cooling mode.
After having pre-xed the established mode, the remote control can only be used to adjust the temperatures. Stoppage
code “d1” “20” will be displayed if an attempt is made to change the operation mode of any of the indoor units with the
remote control.
Example of wiring diagram of xing the operation mode.
Outdoor unit PCB
A
Power
supply
• A: 3P connector cable.
• X1: Cooling.
• X2: Heating.
• SS1: Fixing operation mode switch.
• SS2: Change over switch
2 Demand thermo OFF (3)
This is an input function to control the maximum power that the compressor can consume. When this option is turned on,
the outdoor units are stopped completely, and the indoor units go into thermo-OFF. Alarm “10” is displayed on the remote
control. If the switch of this function is disconnected it becomes available again.
Connect the cabling and use the materials as shown in Available ports.
3 Forced stoppage (4)
This is an input function that turns on when the switch receives a signal that causes the compressor and the fan motor of
the indoor unit to stop; alarm “10” displays on a remote-controlled when this option turns on. If the switch of this function is
disconnected it becomes available again.
Connect the cabling and use the materials as shown in Available ports.
4 Current control demand (5/6/7)
This is an input function that turns on when it detects that the frequency of the compressor reaches 60%, 80% or 100%.
The frequency of the compressor is determined when the maximum current reaches the established limit.
Connect the cabling and use the materials as shown in Available ports.
If the running current of the outdoor unit exceeds the maximum limit, the unit changes to the thermo-OFF condition. Stop-
page cause code “10” will appear. When the input terminal is opened during the demand current control, the control of the
input terminal is reset.