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Siemens Building Technologies  Basic Documentation LMV5...  CC1P7550en 
HVAC Products  19 Addendum 4: LMV52... with O2 trim control and O2 module  13.08.2004 
 
19  Addendum 4: LMV52... with O2 trim 
control and O2 module 
 
19.1 General 
 
The LMV52... system is an extended LMV51... system. A special feature of the 
LMV52… is control of the residual oxygen content to increase the boiler’s efficiency. 
 
In addition to the features of the LMV51..., the LMV52... provides O
2 trim control, con-
trol of a maximum of 6 actuators, control of a VSD, and acquisition of cumulated fuel 
consumption and current fuel throughput. The LMV52... system uses an O
2 sensor 
(QGO20...), an external O
2 module, and the standard components of the LMV51... sys-
tem.  
 
The PLL... O
2 module is a detached measuring module for the QGO20... sensor and 
for 2 temperature sensors (Pt1000 / LG-Ni 1000). The module communicates with the 
LMV52… via CAN bus. 
 
The fuel meters must be connected directly to the fuel-related inputs of the basic unit. 
On the AZL5... display and operating unit, the individual consumption values can be 
read out and the meter readings can be reset. 
 
M
Supply air
temperature
sensor
O2 module
PLL...
QGO20...
7550z07e/0704
CAN
LMV52.200...
Flue gas
temperature sensor