6
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2WAY SYSTEM
Trouble Diagnosis
6
4. 2WAY Alarm Codes
E25 Alarm
Alarm code
Alarm meaning
Alarm conditions
address as that unit 5 times or more within 3 minutes.
Probable cause
Check
Correction
Example
Notes
E25
Outdoor unit address setting failure (duplication)
Communication by outdoor unit main-sub control wiring was received that contained the same
The unit number is set incorrectly.
Check the unit number again.
Correct the incorrect unit number setting.
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Recovery from this alarm occurs automatically (when communication that contains the same
address is not received for 3 minutes).
E26 Alarm
Alarm code
Alarm meaning
Alarm conditions
detected on the outdoor unit main-sub control wiring for 3 minutes or longer.
Probable cause
(2) The outdoor unit main-sub control wiring is disconnected.
Check
(2) Check the outdoor unit main-sub control wiring.
Correction
(2) Repair the outdoor unit main-sub control wiring.
Example
Notes
E26
Mismatch in outdoor unit quantity
After power initialization, the set outdoor unit quantity did not match the number of outdoor units
(1) The outdoor unit quantity is set incorrectly.
(1) Check the outdoor unit quantity setting again.
(1) Correct the incorrect outdoor unit quantity setting.
—
Recovery from this alarm occurs automatically (when the set outdoor unit quantity matches the
number of outdoor units detected on the outdoor unit main-sub control wiring).
E29 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
(1) After initial communications were completed, the outdoor unit main-sub control wiring was
disconnected.
(2) After initial communications were completed, the RC connector became disconnected.
(3) The power at the outdoor unit (main unit) is turned OFF.
Check
(2) Check the RC connectors.
(3) Check the power at the outdoor unit (main).
Correction
(2) Correct the RC connector connection.
(3) Turn ON the outdoor unit (main) power.
Example
Notes
E29
Outdoor unit failed to receive communication from outdoor unit (main).
Outdoor unit communications from outdoor unit (main) were interrupted for 3 minutes or longer.
(1) Check the outdoor unit main-sub control wiring.
(1) Repair the outdoor unit main-sub control wiring.
—
—
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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SM830204-05_2WAY SYS.indb 12
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