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Siemens Building Technologies Electronic Air / Fuel Ratio Control System CC1P7873.1en
HVAC Products 3 General 15.10.2002
3.1 Application
The electronic control units RVW25... and RVW26... are designed for use with modu-
lating single- or dual-fuel burners.
The RVW26... can control the following devices:
· 1 variable speed drive as defined by the RVW25... for controlling the fan speed
· 1 or 2 auxiliary actuators for auxiliary functions «AUX1 (1) / AUX1 (2) (SA5 / SA6)»
· 1 auxiliary actuator «AUX2» for auxiliary functions (SA7)
The auxiliary actuators can be used for control tasks where an actuating device re-
sponds to changes in burner output, for example:
· Throttling damper in the flue gas recirculation
· Adjustable burner head
· Flue gas damper for combustion chamber pressure control
· Primary air damper with burners using staged air supply
The following illustrations show a choice of applications:
In all application examples, actuators «SA2...SA4» are controlled by the RVW25... and
actuators «SA5...SA7» are controlled by the RVW26...
The variable speed drive is controlled by the RVW26... as defined by the RVW25...
FUEL
AIR
SA2
M
M
SA5
78731c01/0601
M
M
SA4
FU
Fig. 3 Single-fuel burner with no auxiliary functions