SiBE04-101
Troubleshooting
Service Diagnosis
115
4.24
Detection of Low Voltage (LVP)
Remote Controller
Display
U2
Outdoor unit LED
Display
A
5
1
4
2
3
3
3
4
4
Method of
Malfunction
Detection
Abnormal voltage decrease in the DC section.
Malfunction
Decision
Conditions
When an low voltage signal is sent from the low voltage detection circuit to the microcomputer.
The system shuts down after low voltage is detected 255 times.
The malfunction counter is reset when there is no operation shutdown due to an malfunction (including
operation halt due to other cause) for 60 minutes (cumulative time) of compressor operation after the
malfunction condition is canceled.
Supposed Causes
Abnormal power supply voltage
Malfunction of low voltage detection section
Malfunction of PAM control parts or SSR
Troubleshooting
Is the power
supply voltage within the
specification?
Check the power supply voltage.
YES
NO
Correct the power supply.
Replace the outdoor unit PCB.
Replace the outdoor unit PCB.
Replace the capacitor.
Turn off the power switch.
Repeat 2 or 3
times.
After making sure that there is
no DC voltage, measure
capacitor voltage.
External factors
l
Noise
l
Voltage distortion
NO
Turn the power
switch on. Does the capacitor
voltage increase (or
decrease) gradually?
YES
YES
NO
Check the capacity of the main
circuit capacitor.
Does the unit restart
when the power switch is
turned back on?
(R1069)
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
SiBE04-101.book Page 115 Monday, October 15, 2001 3:08 PM