Hitachi YUTAMPO Series Service Manual page 73

6 Troubleshooting
Outdoor unit
No
Yes
LD301 blinks 10 times.
Power supply voltage error
No
Yes
LD301 blinks 7 times.
Thermistor abnormality
No
Yes
LD301 blinks 6 times.
Increase of compressor
temperature
No
Yes
LD301 blinks 16 times
High load stop
No
Yes
LD301 blinks 5 times.
Operation stopped
due to heavy load of
Exceeded the lower limit of
the compressor.
overload
No
Yes
LD301 blinks 4 times
This is a failure in starting up the
compressor. Check the compressor
connectors for looseness and continuity.
Switchover failure
No
Yes
Operation stopped due to the detection of
LD301 blinks 3 times.
abnormality by the compressor control. It
may be an abnormality of the drive circuit
Abnormally slow rotation
in case of heavy load.
No
Yes
Operation stopped due to the detection of
LD301 blinks twice
abnormality by the compressor control. It may be an
abnormality of the compressor and an abnormality of
Peak current cut
the drive circuit in case of heavy load.
65 SMGB0135 rev.0 - 06/2020
AC voltage lower than 187 V or greater than 253 V
Is there a voltage of AC 220-230 V
between terminal boards L and N?
AC voltage between 187 and 253 V
Is DC voltage between 264 and 358 V? Refer to
the label on the cover of the electrical parts for the
measuring points.
Normal
Check for loose or poorly inserted thermistors.
Normal
Check the thermistors for wire breaks and short-circuits.
Normal
An increase of compressor Check whether the OH thermistor is loose or poorly inserted.
temperature has been
detected by the OH
thermistor.
Check the OH thermistor for wire breaks and short-circuits
Normal
* This is not a failure in case that
operation continues after restarting.
Compressor stopped since current exceeded
the threshold value due to high load. It
restarts after a fixed time (3 minutes).*
Is the heat exchanger of the outdoor unit clogged
or are its surroundings blocked by something?
Is there any abnormality in the refrigerating cycle?
Abnormal
Check for
loose or poorly
inserted reactor.
Abnormal
Abnormal
Abnormal
Normal
Abnormal
Inspect the refrigerating cycle.
(It may be due to a cause such
as refrigerant leakage)
Yes
Remove the cause of the
problem.
No
Yes
Fix the point of abnormality.
No
No
Is the service valve open?
Yes
Abnormal
Check the compressor
for loose connectors and
continuity of the cord.
Normal
Is a leakage breaker
installed?
No
Abnormal
Is the insulation of the compressor
normal? Check it with a megger.
Normal
Conduct a "self-check"
Check the power supply.
Check the connection of the
reactor wire. If it is OK, please
replace the reactor.
Replace the outdoor electrical
parts (due to circuit abnormality).
Replace the outdoor electrical
parts (due to abnormality in the
voltage detection circuit).
Fix the connection of the
thermistors.
Replace any abnormal
thermistors.
Replace the outdoor electrical
parts (due to abnormality in the
thermistor detection circuit).
Fix the connection of the
OH thermistor.
Replace the OH thermistor.
In case that inspecting the refrigerating cycle
does not help to solve the problem, replace
the outdoor electrical parts (due to abnormality
in the thermistor detection circuit).
Open the service valve
Fix the point of
abnormality.
Replace the compressor and
inspect the outdoor electrical
parts.
Replace the parts found to be
defective based on the results of
the "self-check" evaluation.
6