Hitachi RAS-4-HNCE - Page 133

5. Control System
119
SMGB0079 rev.0 - 01/2013
5
The gure below shows the outline of the control system
Transmission
circuit
Remote
control MCU
Wireless remote control switch
Wireless transmission circuit
A+D conversion
circuit
Thermistor for inlet air
Thermistor of discharge air
Thermistor for gas pipe
Thermistor for liquid pipe
A+D conversion
circuit
Suction gas pressure sensor
Discharge gas pressure sensor
Thermistor for outdoor temperature
Discharge gas thermistor
Thermistor for heating evaporation temp.
Protection circuit
Inverter control
MCU
Inverter power
section
MC
CT1
Outdoor unit MCU
Inverter control
for fan MCU
Relay drive
circuit
Electrical control
expansion valve
drive circuit
Transmission
circuit
Transmission
circuit
Protection
circuit
Fan control
Indoor unit MCU
Transmission
circuit
Relay drive
circuit
Electrical control
expansion valve drive
circuit
Remote
control MCU
Remote control switch
CH1
MV
MOF1
RVR
SVA
B.F.
MOF2
MV MS MIF
Indoor unit Outdoor unit
Multiple signals
Single signals
Operation signals
To the transmission of the
next indoor unit or the next
outdoor unit (H-Link)
PSC
Power source
(*)
Symbol Name Symbol Name
MC Motor (for compressor) CH Crankcase heater
MIF Motor (for indoor fan) CT1 Current transformer
MOF1, 2 Motor (for outdoor fan) RVR 4-Way valve
MS Motor (for auto-louver) SVA,B,F Solenoid valve
MV Electronic expansion valve PSC Pressure switch for control
CMC Compressor magnetic contactor EHW Electric heater
(*) For RAS-12HN(P/C) models. Other than this, the two fan motors are controlled by the Inverter.