Siemens RWF55.50A9 - 2-Stage Burner, 3-Position Output

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Building Technologies Division User Manual RWF55... CC1U7867en
Infrastructure & Cities Sector 5 Operating modes 05.11.2013
5.2.3 2-stage burner, 3-position output
In area (1), the thermostat function is active. In area (2), the RWF55 as a 2-position
controller acts on the second stage via relay K2 (OPEN) and relay K3 (CLOSE) by
switching on at switch-on threshold HYS1 and switching off at switch-off threshold HYS2.
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Figure 10: Control sequence of 2-stage burner, 3-position output
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 actual value falls again below switch-on threshold HYS1. If the response threshold
(q) is exceeded, the controller switches to high-fire operation (A).
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Reference!
See chapter 5.6 Response threshold (q).