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8 Control Mode
8.2.3 Standby
8.2.3.1 Standby mode
In this mode the ETAMATIC enables a switchback to pilot burner mode. The burner re-starts
without pre-purge in the 2
nd
safety time.
You can activate STANDBY mode, if the internal firing rate controller is active or if an external
input or output command can be connected to LSB module or fieldbus (see parameter 812,
access level 4).
As soon as the burner firing rate controller detects that a shutdown of the burner is necessary,
the burner closes the contact at the LSB or the appropriate bit is set to high by field bus. This
does not lead to a shut down. STANBY mode is activated instead.
The STANDBY mode drives the firing rate value to the ignition point and waits for ignition
acknowledgement. Ignition valve and ignition transformer are switched on first. The recircula-
tion channels run to CLOSE position. Ignition position has to be active. After an idle time (sta-
bilisation time) the valve gas 1 (if fuel = gas) is closed for purging the gas system.
Afterwards all fuel valves but the ignition valve stay closed. If set the performing of a valve
leakage test after operation at fuel gas starts now.
Afterwards the ignition transformer shuts OFF. Only the ignition valve remains open.
Fig. 8-5 Sequence at gas operation
*DK = Valve leakage test after operation. During that time the ignition transformer is active.
Fig. 8-6 Sequence at oil operation
The sequencer is now in STANDBY mode with active pilot flame. Ignition position acknowl-
edgement must apply all the time.
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