Lamtec CMS, Manual

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5 Functional Description with Process Diagrams
Fig. 5-13 Oil train for standard process flow oil modulating with pilot burner
Time of Purge after Operation
The purging takes place before an optionally configured post-purge and the valve leakage test
following operation (relevant when switching off from mixed operation). The post-purge and
valve leakage test are delayed correspondingly, and then run afterwards in parallel as before.
Restarting with Extended 2
nd
Safety Time when Igniting - Flag
CMS sets a failsafe flag which stores the outcome of whether the last oil gun purge was suc-
cessful or not.
If a purge was successful then the oil gun/lance is deemed to be empty and the 2
nd
safety time
is correspondingly extended by the relevant parameter value for ignition with oil to allow time
for the oil gun/lance to be primed. The flag is retained even in the event of a power outage or
fault.
If the purging was not completed successfully, the next system start is a regular start and does
not involve any extension of the 2
nd
safety time.
NOTICE
Recommendation:
If the purging process does not complete without errors, the burner must be restarted and
must be purged again. This prevents oil residues drying onto the inside of the oil gun.
The higher-level control functions and instructions for operating personnel must be document-
ed as appropriate.
NOTICE
A fault shut-down during purging can lead to a situation where the gun is only partially dis-
charged. Since the flag for extending the safety time during the start is not set in this case, the
regular safety time is used for the start. This, in turn, can lead to a series of ignition failures.
5.2.3.5 Purging with Digital Input
Requirements for ’Purging by digital input’
• Burner switches OFF.
• The flame mus be OFF.
A pulse is set by the input signal ’Start purging’, which initiates the sequence ’Burner start’.