Hitachi YUTAKI Series - Page 182

Troubleshooting
Service Manual
180
Troubleshooting procedure
SMGB0066 rev.0 - 12/2009
 

↔


• ThealarmcodeisdisplayedonthePCB´sdisplay.
• ItappearsTheelectroniccontroldisplaysthealarmduringtheoperationinheathingorcoolingmode.
– This alarm code is displayed when the suction pressure (Ps) is less than 0.1 MPa during 3 seconds.


note
In case that the low pressure is higher than 2.0 MPa, segment shows 2.0 MPa. -
In this case, check if the high pressure value "Pd" shown in segment is higher than 1.0 MPa. -
Is connector CN3 on the
Printed circuit Board (PCB1)
correctlyconnected?
Wiring Check
(Breakingofwire,wrong
wiring)
No
Yes
Is High Pressure and Low
Presure shown in segment
as"Pd"and"Ps"coincident,
duringcompressorStop?
Yes
Shortage of Refrigerant/ Gas leakage
No
Clogging of expansion valve
Clogging of low pressure side piping
Not enough air going through heat exchanger
Malfunction of check valve
Airowisnotsucient
Defrost incomplete
Is Low Pressure Sensor
Output character and
High Pressure Sensor display
value "Pd" proper during
compressorStop?
Yes
Replace PCB
Is the voltage between
VCC12 and GND1 12V on
PCB1?.
Yes
Replace Low Pressure sensor
No
No
Replace PCB