Startup - Siemens RVW26.000B27 Basic Documentation

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Siemens Building Technologies
HVAC Products

5.2 Startup

Burner control
«R»
When control contact
in the start control loop closes,
the burner control initiates its
startup sequence:
Startup
Delivers positioning command
to open the actuators.
«t1»
Starts prepurge time
«t1»
Prepurging
«t1»:
On completion of
Delivers positioning command
to close the actuators until
ignition load is reached.
Continues with its program:
Opens the first fuel valve and
«t4»
starts interval .
t4
«t4», the
On completion of
second fuel valve opens (if
present). After another
interval, the load controller
will be released.
78731f02e/1201
Electronic Air / Fuel Ratio Control System
5 Description of functions
+ RVW25
QUIT
Q1 = 230 V
G
LKA
+ RVW25
QUIT
Q1 = 230 V
LKM
+ RVW25
QUIT
Q1 = 230 V
BV1
RVW25
Q2 = 230 V
RVW25
LR
X1
LR
TxD
RxD
RVW26
Q1 RVW26... indicates it is ready to
start when Q1 = AC 230 V
RVW26... identifies burner startup
Q3
Sets Q1 = 0 V
Y10
End switch test of actuators:
All actuators are briefly driven toward
fully open and are then closed again.
If test is successful, all actuators will
open
Q1
Full opening of all actuators is
indicated when Q1 = AC 230 V
Y20
Sets Q1 = 0 V
Drives actuators to the ignition
position
Q1 Indicates that these positions are
reached when Q1 = AC 230 V.
Q2
«INTERVA»
Starts the set interval
and indicates to the RVW25...
Y8
that burner operation (Q2 = AC 230 V)
has been detected (Y8 = AC 230 V)
INTERVA
U1
«INTERVA»,
On completion of
the actuators are driven to the ratio
control positions as quiquly as possible.
That position can be different from the
ignition load position. The RVW26...
has thus reached its operating position.
«U1» will be
The signal at terminal
interpreted as a controller signal to
be passed on to the actuators
RxD
The digital signals at TxD and RxD are
used for optimizing the dynamic
TxD
behavior of air / fuel ratio control
Display
-0.-
-1.-
-2.-
-3.-
-4.-
-5.-
-6.-
-7.-
.
CC1P7873.1en
15.10.2002