Modulating Control : Siemens RWF 40
Basic display
The diagram below shows the RWF40 after switching on the supply voltage. This conditions is called the
basic display. The actual valve and the currently active set-pint are shown here. Manual operation, self-
optimisation, the operating parameter and configuration levels can be activated from here.
To change the working set point
The operating display shows the actual pressure/temperature of the boiler in red and the required set point
pressure/temperature beneath in smaller green digits. One quick press of the PGM button, the display
changes to show the set point as the larger red digits and the SPI in the lower small green digits.
Alter the red display using the up/down buttons to show the new required set point, press exit or let the
unit time out to return to the basic display which should be the new set point figure.
To enter a new parameter
The parameters dictate the way in which the burner firing rate alters in response to changes in the
pressure/temperature of the boiler.
A major factor that determines the need to change the parameters is if the burner is fitted to a steam or hot
water boiler. The table below indicates the parameter and its setting for steam and hot water boilers. It
must be emphasised that it is only an indication and any departure from these settings should be made in
small increments, with time given to see how the burner is reacting to the changed parameter.
Press and hold the PGM button down until the green set point figure changes to an AL, the larger upper
figures show the value. Use the up/down buttons to set the new values, press the PGM button to enter the
value and change to the next screen. To cancel an entry press exit. Scroll through the screens, (PGM
button) modifying any value found to be in error (up/down buttons). At the last screen the PGM button
will return the controller to the original display.
At any point in the procedure the original operating display can be obtained by letting the unit time out,
the value in the display at the time out will be accepted.
A value can only be altered within the permitted range of that parameter. All other parameters must
remain as supplied.
Note: The detector range parameters SCL & SCH are given as °C for Hot Water (temperature) and bar for
Steam (pressure).
MOL 3400-4100 Issue 2 10/08
Page 29
K6
PGM
EXIT
SIEMENS
Landis & Staefa RWF40
Burner enable
Reduce output
Increase output
Manual operation
Limit comparator
Increase value
Exit key
Process value display (red)
Setpoint display value (green)
Reduce value
PGM key
RWF Recommended Settings
Parameter Display
Hot
Water
Steam
Proportional
band
Pb1 10 1
Derivative time
Dt
10
5
Reset time
Rt
50
20
Actuator time
Tt
Set to the air Damper
running time between low
and high flame
Switch on
threshold
Hys 1
0
0
Upper off
threshold
Hyst 3
99.9
999.9
Detector:
range start
SCL 0 0
Detector:
range end
SCH 100 25
