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W-2WAY ECO-i SYSTEM
Trouble Diagnosis
4. W-2WAY ECO-i Alarm Codes
P04 Alarm
Alarm code
P04
Alarm meaning
High-pressure switch activated.
Alarm conditions
The operation of the electronic circuit in the high-pressure switch may short-circuit the terminal
depending on the pressure. A pressure of 3.3 MPa or above will short-circuit the terminal. Once
the terminal is short-circuited, it will remain in that state until the pressure goes below 2.6 MPa.
Probable cause
(1) Failure of the check valve in the compressor discharge tube.
(2) The service valve is closed.
(3) Clogging of the outdoor heat exchanger during cooling.
(4) An air short in the outdoor unit during cooling.
(5) Failure of the outdoor fan during cooling.
(6) Clogging of the air fi lter in the indoor unit during heating.
(7) An air short in the indoor unit during heating.
(8) Failure of the indoor fan during heating.
(9) Clogging of the refrigerant circuit.
(10) Failure of the mechanical valve.
(11) Failure of the solenoid valve kit.
(12) Too much refrigerant has been charged.
(13) Failure of the high-pressure switch.
Check
(1) Make sure that the high-pressure switch connector has been properly connected.
(2) If the high-pressure switch is properly connected, connect a high-pressure gauge to the
high-pressure outlet port and monitor the pressure during operation to check the pressure
when the high-pressure switch is activated. Check valve failure is likely if the pressure is less
than 3.3 MPa. The following describes checks to be made when the pressure is high.
(3 During cooling, check whether the outdoor unit heat exchanger is clogged. Remove any
foreign material that prevents ventilation.
(4) During cooling, check whether an air short blockage has occurred in the outdoor unit. The
system is operating normally unless the temperature around the outdoor unit is excessively high.
(5) During cooling, check for outdoor fan failure. Check whether the screws securing the fan are
loose and whether the fan connector in the outdoor unit PCB is properly connected.
(6) During heating, check whether the air fi lters in the indoor unit are clogged. If clogged, clean
the fi lters.
(7) During heating, check whether an air short blockage has occurred in the indoor unit. The
system operates normally unless the temperature around the indoor unit is excessively high.
(8) During heating, check for indoor fan failure.
(9) Check whether the refrigerant circuit is clogged. Check that all service valves are closed.
Check whether welded locations are clogged.
(10) Check for mechanical valve failure. Check whether the mechanical valves make a clattering
sound when the power is reset. Since the mechanical valve in the indoor unit is in a location
that makes aural inspection diffi cult, use an electric means to check. Check that the
connector pin of the mechanical valve on the PCB outputs 4 V. In addition, check that the coil
resistance of the mechanical valve is several tens of
Ω
.
(11) Check for solenoid valve kit failure. Removing a coil that is on will result in a clicking sound.
Also, removing a coil that is off will not produce such a sound.
(12) Check whether too much refrigerant has been charged. Too much refrigerant has been
charged if the sub-cool temperature of the condenser is 15ºC or more.
Correction
Replace damaged components and correct the amount of charged refrigerant.
Example
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Notes
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P05 Alarm
Alarm code
P05
Alarm meaning
Reverse phase (or missing phase) detected
Alarm conditions
This alarm occurs when a reverse phase or missing phase is detected in the L1-L2-L3-N phases.
Probable cause
Reverse phase or missing phase in the L1-L2-L3-N phases
Check
Check the wiring at the power terminal plate.
Correction
Switch the phases and reinsert. Check if the result is OK.
Example
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Notes
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P16 Alarm
Alarm code
P16
Alarm meaning
Compressor 1 (INV) overcurrent alarm
Alarm conditions
This alarm occurs when current trouble or current detection trouble occur at an inverter frequency
of less than 80 Hz after start (when trouble judgment current is detected in the primary or
secondary current, or when an instantaneous secondary current of 13.5 A or higher is detected.
Probable cause
There is a strong possibility of a compressor failure.
An alarm occurs for current detection trouble when it is judged that no current is fl owing after
start (DCCT is damaged). In this case, the cause is a DCCT failure.
Check
Check the power wiring and connector wiring.
Correction
It is possible to resolve this trouble by limiting the maximum frequency.
Example
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Notes
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W-2WAY ECO-i SYSTEM̲Eng5.indd 24
W-2WAY ECO-i SYSTEM̲Eng5.indd 24
2008/09/02 19:11:02
2008/09/02 19:11:02
