Panasonic U-72MF1U9, Руководство по обслуживанию

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Trouble Diagnosis
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Blinking inspection display (2) (compressor magnet SW seizing detection)
Alarm code
Alarm meaning Compressor magnet SW seizing detected
Status: The compressor and outdoor unit fan motor continue to run even though all indoor units
within that refrigerant tubing system are stopped.
Because the fan is running only at the outdoor unit where seizing was detected, check
the corresponding outdoor unit.
* The fan may also run on its own when fan cracking prevention control is in effect or
when snowfall sensor input is present. Therefore monitor for approximately 10
minutes if the outdoor unit fans are operating at multiple units.
Alarm conditions Current is detected in the CT circuit when the compressor is stopped.
(1) This control is not engaged for the first 30 seconds after the compressor turns ON
→
OFF.
(2) For 1 minute following the first 30 seconds after the compressor turned ON
→
OFF, the
threshold for the detected current is 10 A or more continuing for 2 seconds.
(3) All times other than the above:
If the low-pressure SW has not activated, the threshold for the detected current is 7 A or
more continuing for 5 seconds.
If the low-pressure switch has activated, the threshold for the detected current is 7 A or
more continuing for 2 seconds.
Probable cause (1) Magnet SW malfunction
The magnet SW has seized, and the compressor is continuing to run.
→
Even when the power is turned OFF, the primary side and secondary side contacts
remain together.
The conditions of magnet SW operation are poor (difficult to open).
→
When a magnet SW is used in a DC circuit, it may be difficult for the SW to open at
times. In an AC circuit the magnet SW should open instantaneously as long as the
current is within the allowable range. However, this kind of trouble can occur if
excessive current flows, and may prevent the SW from opening.
(2) CT circuit failure or PCB failure (A/D failure)
CT circuit contact failure
→
Check that the connector is not partially disconnected.
Wiggle the connector to check the connection.*
* These symptoms will not occur if the connector is completely disconnected or the
wire is cut. In these cases alarm Hx3 occurs.
Current of 7A or higher was detected although the compressor was stopped, or a
higher current was detected at occasional intervals.
The compressor continues to operate at a time when the outdoor unit should be
stopped (such as when all indoor units are stopped).
→
Check whether or not 208-230 V is output from the PCB to the magnet SW. If the voltage
is output, there is a PCB failure.
(3) Installation error
CT1 connector is connected to the compressor 2 side
CT1 circuit is connected to the compressor 2 side
CT2 connector is connected to the compressor 1 side
CT2 circuit is connected to the compressor 1 side
Correction (1) Replace the CT circuit.
(2) Replace the magnet SW.
(3) Replace the PCB.
Notes –
If the above probable causes are not the cause of the alarm, it is possible that in rare cases
the alarm may be caused by the effects of noise. See notes.
(Blinking inspection display)
4. Blinking (Inspection) Display on the Remote Controller
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