Signaling Of Start Preventions; Safety Shutdown In Standby Mode; Forced Intermittent Operation - Siemens LMV50 Series Manual

Building Technologies

4.2.3.3 Signaling of start preventions

If startup is prevented, it is always displayed on the AZL5.
Startup is prevented only when there is a heat request and if 1 of the start criteria is not
satisfied. The time from the moment start prevention occurs to the display on the AZL5
can be set via parameter DelayStartPrev.
It is also possible to signal start preventions via the alarm output. This function can be
activated and deactivated via parameter AlarmStartPrev.
If Signaling start preventions is activated via the alarm relay, it is advisable to pick up
power for the reset from the alarm output to prevent inadvertent manual lockouts.
The time from start prevention to signaling at the alarm contact can be set:
Parameter DelayStartPrev
AlarmStartPrev (activated / deactivated)
AlarmDelay

4.2.3.4 Safety shutdown in standby mode

This parameter is used to determine the shutdown behavior should errors in standby
mode occur, so that events (e.g. opening of safety loop) in standby mode which, in
case of a heat request, would lead to start prevention, trigger safety shutdown and –
when the respective repetition counter has elapsed – lockout.
Parameter Standby Error (activated / deactivated)

4.2.3.5 Forced intermittent operation

No matter if the LMV5 is used for continuous operation or intermittent operation (e.g.
when using a flame detector type QRB), forced intermittent operation can be activated,
meaning short automatic shutdown after 23 hours and 50 minutes of uninterrupted
operation.
As a general rule, it is recommended to activate forced intermittent operation or to
leave it activated.
Forced intermittent operation should only be deactivated in plants where this function is
not desired or is unacceptable.
Parameter ForcedIntermit (activated / deactivated)
Basic Documentation LMV5...
4 Burner control
65/327
CC1P7550en
22.05.2018