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Building Technologies Division  Basic documentation LMV36...  CC1P7544en 
Infrastructure & Citiies Sector  18 Connection to superposed systems  25.09.2013 
 
 
Note 
Fuel changeover on the basic unit. 
 
After a change of fuel, the BAC system must rewrite the predefined target output. A 
change of fuel can be detected by cyclic sampling of the type of fuel currently burnt.
 
 
General setting values for connection of the basic unit to building automation (for factory 
settings, refer to the Parameter list): 
 
Bus communication may only be interrupted for the time set. 
If communication is disturbed for a longer period of time, the LMV36... basic unit delivers 
a fault status message and the values set in the basic unit by building automation are 
reset. 
 
No. Parameter 
141 
Operating mode BACS 
0 = off 
1 = Modbus 
2 = reserved 
142  Setback time in the event of communication breakdown 
 
Setting value: 
0 = inactive 
1…7200 s 
148  Default output if communication with building automation is interrupted  
Setting values: 
 
For modulating operation the setting range is as follows: 
0…19.9 = burner OFF 
20…100 = 20…100% burner rating 
 
For multistage operation, the following settings apply: 
0 = burner OFF, P1, P2, P3 
Invalid = no default output from building automation 
 
Default setting: Invalid 
149  Fuel 1: Default output if communication with building automation is 
interrupted  
Setting values: 
 
For modulating operation the setting range is as follows: 
0…19.9 = burner OFF 
20…100 = 20…100% burner rating 
 
For multistage operation, the following settings apply: 
0 = burner OFF, P1, P2, P3 
Invalid = no default output from building automation 
 
Default setting: Invalid 
 
The factory settings of the parameters are shown on the Parameter list. 
 
 
Note 
For a detailed description of parameters 148 and 149, refer to chapter Default output 
via building automation.