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Siemens Building Technologies  Basic Documentation LMV5...  CC1P7550en 
HVAC Products  4 Burner control  13.08.2004 
 
4.2 Program sequence 
 
The sequence diagrams show the program sequence in detail (refer to 4.2.5 Sequence 
diagrams). 
 
4.2.1 Parameters 
 
The most important time parameters for the program sequence are the following (refer 
to 7.5 Menu and parameter lists): 
−  Prepurge time 
−  Preignition time / circulation time heavy oil 
−  Safety time 1 (TSA1) 
−  Safety time 2 (TSA2) 
−  Interval 1 
−  Interval 2 
−  Postpurge time 1 (t8-1) with FGR damper shut (this part of the postpurge time is al-
ways executed) 
−  Postpurge time 3 (t8-3) with FGR damper open (this part of the postpurge time will be 
interrupted when there is demand for heat) 
−  Postpurging in the lockout phase (if G = ON before lockout occurred) 
 
All the times mentioned above - with the exception of «Postpurging in the lockout 
phase» - depend on the type of fuel, which means that different times can be set for oil 
and gas. 
The prepurge time and the safety times are safety-related. This means that, using the 
AZL51…, the heating engineer can only readjust them in the «safe» direction (against 
internal maximum or minimum values). 
In other words, «ts» times can only be shortened and «tv» times can only be extended. 
Time parameters