Hitachi YUTAKI Series - Troubleshooting; Alarm Code Indication on Remote Control Switch; Alarms for Indoor units

181
Troubleshooting procedure
SMGB0066 rev.0 - 12/2009
Troubleshooting
Service Manual
7
 

↔


• ThealarmcodeisdisplayedonthePCB´sdisplay.
• Thecompressorstopsandrestartsautomaticallyin3minutes.
• TheStopalarmappearsafter3retriesduring30minutes.
– This alarm code is displayed when the Pressure Ratio calculated from High Pressure "Pd" and Low Pressure
"Ps" is less than 1.8 MPa during 3 minutes.



Pressure Ratio=
High Pressure "Pd" + 0.1
Low Pressure "Ps" + 0.1

Pd= 1.6 MPa
Ps= 0.7 MPa
1.6 + 0.1
0.7 + 0.1
= 2.13
Pressure Ratio =
AreconnectorsCN3,CN4
on the Printed Circuit Board
(PCB1),LowpressureSensor
and High Pressure Sensor
correctlyconnected?
Wiring Check and Repair
No
Yes
No
Yes
Are DIP switch DSW8 and
DSW9 on PCB1 correctly
connected?
(See setting of DIP switch for
correct setting).
Check DIP switch setting and
set it correctly
Are High Pressure and Low
Pressure shown in segment
as "Pd" and "Ps" almost
coincident,duringcompressor
Stop?
Yes
PCB1 and Pressure Sensor
forPd,Psarenormal.
See Failure Analysis
No
Failure of Pressure Sensor.
(CheckthePressureSensor,
according the checking
procedure shown in alarm
code "27" and "28").

note
In case that the low pressure is higher than 2.2 MPa, segment shows 2.2 MPa. -
In this case, connect a pressure gauge to high pressure check joint, check the pressure shown in the gauge. -