181
Troubleshooting procedure
SMGB0066 rev.0 - 12/2009
Troubleshooting
Service Manual
7
Alarm code
description
↔
Excessively low pressure difference
• 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.
PCB monitoring position: PCB1, Cn3 and Cn4
retry code: P-11
Calculation formula for Pressure ratio:
Pressure Ratio=
High Pressure "Pd" + 0.1
Low Pressure "Ps" + 0.1
Example:
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.
-
