Panasonic U-8MF2E8 - Sensor Failure Alarms

5
5 - 10
3WAY SYSTEM
Trouble Diagnosis
4. 3WAY Alarm Codes
E25 Alarm
Alarm code E25
Alarm meaning Outdoor unit address setting failure (duplication)
Alarm conditions Communication by inter-outdoor unit control wiring was received that contained the same
address as that unit 5 times or more within 3 minutes.
Probable cause The unit number is set incorrectly.
Check Check the unit number again.
Correction Correct the incorrect unit number setting.
Example
Notes Recovery from this alarm occurs automatically (when communication that contains the same
address is not received for 3 minutes).
E26 Alarm
Alarm code E26
Alarm meaning Mismatch in outdoor unit quantity
Alarm conditions After power initialization, the set outdoor unit quantity did not match the number of outdoor units
detected on the inter-outdoor unit control wiring for 3 minutes or longer.
Probable cause (1) The outdoor unit quantity is set incorrectly.
(2) The inter-outdoor unit control wiring is cut.
Check (1) Check the outdoor unit quantity setting again.
(2) Check the inter-outdoor unit control wiring.
Correction (1) Correct the incorrect outdoor unit quantity setting.
(2) Repair the inter-outdoor unit control wiring.
Example
Notes Recovery from this alarm occurs automatically (when the set outdoor unit quantity matches the
number of outdoor units detected on the inter-outdoor unit control wiring).
E29 Alarm
Alarm code E29
Alarm meaning Outdoor unit failed to receive communication from outdoor unit (main).
Alarm conditions Outdoor unit communications from outdoor unit (main) were interrupted for 3 minutes or longer.
Probable cause (1) After initial communications were completed, the inter-outdoor unit control wiring was
cut.
(2) After initial communications were completed, the RC connector became disconnected.
(3) The power at the outdoor unit (main unit) is turned OFF.
Check (1) Check the inter-outdoor unit control wiring.
(2) Check the RC connectors.
(3) Check the power at the outdoor unit (main).
Correction (1) Repair the inter-outdoor unit control wiring.
(2) Correct the RC connector connection.
(3) Turn ON the outdoor unit (main) power.
Example
Notes
E31 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause When does it occur?
(1)
When failed in rewriting microcomputer.
(2) When the unit power shut down during rewriting microcomputer.
(3) When wiring between PCB and ROM writer disconnected.
Check
(2) Switch on the unit power again.
Correction
Example
Notes
E31
Communication error between two microcomputers on the Control P.C. Board
(1) Rewrite microcomputer again.
Replace Control PCB.
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