10 Troubleshooting
Troubleshooting procedure
SMGB0091 rev.2 - 11/2015
233
10
Alarm code
45
Activation of high pressure increase protection device
When the compressor operates with the discharge pressure (Pd) higher than 3.8 MPa for 1 minute, the retry operation
is performed 3 minutes after compressor is stopped. Thereafter, this alarm code is indicated when above abnormality is
detected twice in 30 minutes.
Is there a leakage of the
solenoid valves (SVA)?
Replace the solenoid valve
(SVA) if faulty
Yes
No
Is the RASC unit stop valve
closed?
Open the stop valve
No
Check if indoor or outdoor intake air
temperature is too high
Correctly connect it
Yes
No
Is the high-pressure sensor
normal?
Yes
Are expansion valves fully closed
and locked?
No
No
Are electric wiring and
refrigerant piping connections
between the indoor and RASC unit
incorrectly connected?
Check the RASC electronic expansion valve during cooling
and the indoor electronic expansion valve during heating.
Check connection of the
RASC PCB1. Replace the
high-pressure sensor if
faulty
Check RASC PCB1 or
connection of RASC PCB1.
Replace the electronic
expansion valves if faulty
Yes
Yes
Phenomenon
Cause
Check item
Action
(Turn OFF the main switch)
Excessively
high discharge
pressure
Leakage of solenoid valve (SVA)
Check the outlet
temperature of solenoid
valve (SVA)
Check connection. Replace
solenoid valve (SVA) if faulty
Closed stop valve
Check stop valve
Open stop valve
Abnormal high pressure sensor
Check connecting condition
and output voltage “CN100”
(on RASC PCB1) for high
pressure sensor
Replace high pressure sensor
if faulty
Excessively high temperature of
inlet air for RASC unit or indoor
unit
Check thermistor for indoor
unit and RASC unit inlet air
temperature
Replace the inlet air thermistor
if faulty
Incorrect connection between
indoor unit and RASC unit
Check electrical
system and refrigerant
cycle system
Correctly connect
Locked expansion valve with fully
closed
Check condition of
connector “CN100” on
RASC PCB1
Repair connector for RASC
PCB1 or expansion valve.
Replace if faulty
Faulty RASC fan motor
Measure coil resistance
and insulating resistance (*)
Replace RASC fan motor if
faulty.
?
N O T E
(*): When the alarm code “45” is indicated, the RASC fan motor may be damaged. Ensure that fan motor is checked according to the
“10.4.3 Fault diagnosis of fan motor”
.