Hitachi RAK-18QXB Service Manual page 85

5.Failure phenomenon:The eco sensor lamp is blinking(on for 4 seconds,off for 1 second)
<Situation> The eco sensor lamp is blinking(on for 4 seconds,off for 1 second)
The infrared human presence sensing function can not be in operation or the sense is blunt.
「Timer lamp is blinking for 20 times」is kept in self-diagonsis memory function.
<Estimated failure locations>
<Cautions> After pressing the「
presence sensing mode is set.The infrared sensor self-diagnosis usually works 1 minute at least to 1 hour at
most to diagnose.Please refer to 「Infrared sensing failure diagnosis service mode 」.
<Diagonsis flow>
Initiating troubleshooting
Is the CN20 connector loose?
Or is there a wire break?
According to 「Infrared sensing failure diagnosis service
mode」 ,can the failure phenomenon be judged?
Refer to the next page 「Infrared sensor checking points」for
rejudgement?
Human infrared sensor checking points
If already used the self-diagnosis way to check out there is no fault but low sensitivity,false action is also occur ,
please check as follows
Structure confirm
・ Is the structure and appearance of frensnel lens ok? Please confirm whether there any dirt or nick on it
Please confirm whether frensnel lens is loose
・ Does the structure of the sensor P.W.B have any problem?
Note
The infrared sensor detects changes to infrared generated by human bodies ,if there is dirt or nick on the
surface of the Fresnel lens,it will distube the detection of the infrared sensor.
If the assembly position is incorrect,the area detected will be incorrect so that it will distube the operation
of the dynamic air deflection function.
The surround environment confirm
The infrared sensor detects changes to the infrared generated by human bodies,therefore ,the accuracy of
infrared sensor may be affected in the following cases:
・
The actibity level is very low or human bodies are locked by a screen, cabinet,or glass board.
・
the indoor temperature is very high and exceeds or approaches the human body temperature
(when the refrigeration just begins).
・ The person wears thick chothes and turns his/her back to the air conditioner.
・ curtains or plant leaves swing due to pet movement oe airflow.
・The sensor board break.
・CN20 connector loose,lead wire break.
」buttons by remote controller,the infrared human
eco sensor
No
No
Yes
Correct the connector.
Yes
Replace the sensor board.
- 85 -