Installation and operating instruction
Combustion manager W-FM 100 und W-FM 200
6 Operation
83054802 1/2018-07 La
131-228
6.12.12 Multi-stage switch differentials and switch thresholds
6.12.12.1 Multi-stage switch differentials
Param & Display
LoadController
ControlParam
Sd_Stage1On
Sd_Stage1Off
Sd_Stage2Off
Sd_Stage3Off
Parameters for the On and Off switch points of the internal load controller for multi-
stage operation.
Parameters
Function
Sd_Stage1On
Switch-on point (controller ON)
Sd_Stage1Off
Switch-off point stage 1 (controller OFF)
Sd_Stage2Off
Switch-off point stage 2
Sd_Stage3Off
Switch-off point stage 3
The on and off switch points are given as a percentage value and relate to the cur-
rent setpoint.
Example
On and off switch points at setpoint (W) = 70 °C
Sd_Stage1On
=
−10 % (of 70 °C = −7 °C)
Sd_Stage1Off
=
+5 % (of 70 °C = 3.5 °C)
Sd_Stage2Off
=
+2 % (of 70 °C = 1.4 °C)
Sd_Stage3Off
=
+1 % (of 70 °C = 0.7 °C)
Stage 1 (controller) ON
70 − 7 = 63 °C
Stage 1 (controller) OFF
70 + 3.5 = 73.5 °C
Stage 2 OFF
70 + 1.4 = 71.4 °C
Stage 3 OFF
70 + 0.7 = 70.7 °C
If stage 1 exceeds
Sd_Stage3Off
before stage 3 has switched, the controller
switches off.
Threshold for stage 2 not achieved
Stage 1 switches off at:
Setpoint (W) +
Sd_Stage3Off
Threshold for stage 2 and 3 not
achieved
Stage 1 switches off at:
Setpoint (W) +
Sd_Stage1Off
Sd_Stage1Off
Sd_Stage2Off
Sd_Stage3Off
Setpoint (W)
Sd_Stage1On
Stage 1 (controller ON)
Stage 2
Stage 3