Daikin RZQG71~140L7V1B Service Manual page 255

CHECK 2
Evaluation of Abnormal High Pressure
Abnormally high pressure level is mostly caused by the condenser side. The following contents are provided
by service engineer based on their field checks. Further, the number is listed in the order of degree of
influence.
In Cooling Operation
Check items (Possible causes)
Does the outdoor unit fan run normally?
Is the outdoor unit heat exchanger clogged?
Is there clogging before or after the EV (capillary)?
Is the check valve clogged?
Is the HPS normal? 
Is the outdoor unit installed under such conditions that
short circuit easily occurs?
Is the piping length 5 meters or less?
Does air enter the refrigerant system?
Is the refrigerant overcharged?
In Heating Operation
Check items (Possible causes)
Does the indoor unit fan run normally?
Is the indoor unit heat exchanger clogged?
Is the indoor unit installed under such conditions that
short circuit easily occurs?
Is there clogging before or after the EV (capillary)?
Is the check valve clogged?
Is the HPS normal?
Is the piping length 5 meters or less?
Does air enter the refrigerant system?
Is the refrigerant overcharged?
244
Judgement
Visual inspection
Visual inspection
Check if there is a temperature difference before and
after EV (capillary).
Check if the main valve unit of EV operates
(by noise, vibration).
Check if there is a temperature difference before and
after check valve.
 If YES, the check valve is caught.
Check continuity by using a tester.
Visual inspection
Visual inspection
Conduct refrigerant collection and vacuum drying, and
then add proper amount refrigerant.
Conduct refrigerant collection and vacuum drying, and
then add proper amount refrigerant.
Judgement
Visual inspection
Visual inspection
Visual inspection
Check if there is a temperature difference before and
after EV (capillary).
Check if the main valve unit of EV operates
(by noise, vibration).
Check if there is a temperature difference before and
after check valve.
 If YES, the check valve is caught.
Check continuity using a tester.
Visual inspection
Conduct refrigerant collection and vacuum drying, and
then add proper amount refrigerant.
Conduct refrigerant collection and vacuum drying, and
then add proper amount refrigerant.
ESIE12-06
Service Diagnosis