Hitachi RAM-52QH5 Service Manual page 39

BLOCK DIAGRAM
MODEL RAM-53QH5
Power source
single phase 50Hz, 220-240V
L
N
M
fan motor
Indoor unit 1
C1/D1
Indoor unit 2
C2/D2
Indoor unit 3
C3/D3
Magnetic relay
Inrush current
protection relay
Rotor position
detector
Overload current
detector
Fan motor
drive circuit
Overheat
thermistor
Defrost
thermistor
Outdoor temp
thermistor
Indoor/Outdoor
Interface 1
Indoor/Outdoor
Interface 2
Indoor/Outdoor
Interface 3
Switching power supply 1
Switching power supply 2
Outdoor Unit
System
Power
Module
Expansion valve
Reversing valve
– 44 –
compressor
M
SPM driver
EEPROM
Expansion valve 1
Expansion valve 2
drive circuit
Expansion valve 3
Expansion valve
Multiplexer
Expansion valve
Expansion valve
drive circuit
Clock circuit
Reset circuit
thermistor 1
thermistor 2
thermistor 3
Reversing valve