Siemens RWF40.002B97 - Modulating Burner, Analog Output; 2-Stage Burner, Floating Output

HVAC Products CC1B7865en 05.12.2002 19/57
5. Operating modes
In diagram area (1), the thermostat function is active.
In area (2), the controller maintains the adjusted setpoint.
A
B
q
A
q
(2)
(1)
W
HYS1
HYS3
X1
0%
100%
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The positioning signal is delivered as a standard signal via the analog output.
F
The modulating controller must be available and configured in the unit (optional).
ð Section 8.2 «C112 limit comparator, controller type, setpoint «SP1», locking»
In diagram area (1), the thermostat function is active.
In area (2), a 2-position controller acts on the second stage, via relay 2 (open) and
relay 3 (close) by switching it into the circuit at the switch-on threshold «HYS1» / and
out of circuit at the switch-off threshold «HYS2».
q
A
B
q
A
I
II
(2)(1)
W
HYS2
HYS1
HYS3
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In area (3), the actual value exceeds the upper switch-off threshold «HYS3» and the
controller shuts down the burner (B). The controller only starts low-fire operation when
the level falls below the switch-on level «HYS1» again. If «Q» is exceeded, the
controller switches to high-fire operation (A).
ð Section 5.6 «Response threshold Q»
5.2.2 Modulating burner, analog output
5.2.3 2-stage burner, floating output