Special Functions During The Control Sequence; Lockout Phase (Phase 00) / Safety Phase (Phase 01) - Siemens LMV50 Series Manual

Β
Safety phase
(phase 01)
Building Technologies

4.2.3 Special functions during the control sequence

4.2.3.1 Lockout phase (phase 00) / safety phase (phase 01)

The safety loop relays are deenergized, the alarm relay is activated, and lockout is
initiated, which means that phase 00 can only be quit via manual reset. In terms of
time, phase 00 is unlimited. During the lockout phase, the fan motor remains off,
provided it was already deactivated in the safety phase. During the lockout phase, the
fan contact is controlled for a selectable period of time.
Parameter PostpurgeLockout
Note!
When using a VSD, give consideration to its shutdown behavior.
Refer to chapter Special features, parameter ShutdownBehav (Unchanged /
PostpurgeP / HomePos).
The safety phase is an intermediate phase that is ended before lockout occurs. The
safety loop relays are deenergized, but lockout will not yet initiated. The alarm relay is
not yet energized.
In the safety phase, the fan motor maintains the state of the previous phase, that is, it
remains on if it was on before, and it remains off if it was off before.
If possible or permitted, safety checks or repetition counter checks are made. Their
results decide on the transition to either Lockout phase or Standby.
The duration of the safety phase varies (depending on the scope of testing), but lasts a
maximum of 30 seconds.
This procedure serves primarily for suppressing undesired lockouts, caused by EMC
effects, for instance.
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