A.O. Smith 300 Series, Инструкция по эксплуатации

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59
YES NO
Water is heated to
set point
24 V Gas Valve
de-energized
60 second
Inter-Purge cycle
24 V Gas Valve
de-energized
Retries up to
two more times
60 second
Post-Purge cycle
Control System
Locks Out
“Ignition Failure”
Fault Msg is
displayed
Water heater goes
into standby mode
If tank temperature drops below Operating Set Point minus
Differential setting a heating cycle is activated
Spark Ignition Transformer is energized
24 V Gas Valve is energized
gas flows to Main Burner
Is flame sensed at the Main Burner ?
(control system monitors the flame sensor)
Control System Locks Out
Displays Fault Msg
NO
Combustion Blower is energized
Pre-Purge cycle
Control System performs diagnostic checks
Normal State of all pressure switches and ECO are checked
Pressure switches and ECO are verified closed
Figure 52.
Sequence of Operation