Hitachi RAK-18QXB Service Manual page 77

Initiating troubleshooting
Are the "timer lamp" (orange) of the indoor unit
blinking?
The product will begin to run in response to a remote
control setting: "cooling mode, temperature setting 16
(summer) or "heating mode, temperature setting 32
(winter).
Has the "operation lamp" been turned on?
Is the compressor running?
Check the freezing cycle.
< Troubleshooting by using the self-diagnosis memory function>
・By using the self-diagnosis memory function, you can check the failure mode ( 1) occurring in the outdoor electrical
parts on the indoor unit side.
Steps 1. Clear the troubleshooting data.
2. Run the product for several minutes under the conditions where the compressor runs.
3. Redisplay and check the data written in the self-diagnosis memory.
・The self-diagnosis memory function can also be used to catch sporadic failure phenomena.
Steps 1. Clear the troubleshooting data.
2. Have the user use the product as usual until a failure phenomenon occurs.
(The period depends on the incidence of the phenomenon.)
3. At a later date, redisplay and check the data written in the self-diagnosis memory.
・ For the outdoor self-diagnosis display (OH thermistor heat-up, overload lower limit cut) stemming from the freezing cycle
or operating condition, the time lag is long from operation startup to the emergence of the phenomenon.
Moreover, it is affected by the temperature, sunshine, operating hours, and other factors of the day, so that the
phenomenon may not be able to be identified at the time of a repair service visit. In that case too, use the self-diagnosis
memory function ( 2).
・ The outdoor self-diagnosis display "overload lower limit cut" and "OH thermistor heat-up" can be identified only when you
are using the self-diagnosis lamp of the outdoor unit and the self-diagnosis memory function of the indoor unit.
Note that this will not be automatically displayed on the indoor unit side.
Diagnosis and troubleshooting of indoor electric parts
No
Yes
Yes
Yes
Perform troubleshooting according to the
self-diagnosis display.
"
"
No
Check the indoor electrical parts.
No
Turn off the power and turn on the power and
press the "forcible cooling" switch to operate the
product.
Has the compressor started to run?
Check the outdoor electrical parts.
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Yes
No