Panasonic CS-Z25YKEA Service Manual page 99

1.2 Duty Rotation mechanism (Controlled by CN-CNT Signal)
Upon turning Duty Rota on ON from OFF, Main unit will be always be turned on first (becomes running
unit). Sub unit will become the backup unit. Running and backup unit will rotate based on a rota on
interval set from remote controller. A er rota on interval ends, Main unit will be turned off (becomes
backup unit) and Sub unit will be turned on (becomes running unit) for the next rota on cycle. Role of
running and backup unit will rotate between Main and Sub unit for each new rota on cycle.
Duty Rotation = ON
Figure 1.2 Rotation of running/backup unit roles between Main and Sub unit
1.3 Unit response to error and breakdown (Controlled by CN-CNT Signal)
When error is encountered during duty rota on, remocon sends signal accordingly to ensure that there
is at least one unit running to maintain air-condi oning. This is the general trend of remocon response:
Situa on
encountered by unit
System error
Communica on
error
Power breakdown
A. Unit response when error is encountered during duty rota on
1. When a CNT communica on error is detected on the running unit, the running unit will
con nue its previous state (no signal sent from remocon) but backup unit will be turned on by
remocon with rota on counter reset.
Main Unit
Sub Unit
Running Backup
Unit response
Turned off due to error detec on
Resume previous
communica on restored
Resume previous
breakdown
Main Unit
Backup
Remocon Signal Response
Turn on backup unit
state un l Turn on backup unit, and check
communica on with error unit
state a er None (due to no power)
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Sub Unit
Running