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Building Technologies Basic Documentation LMV5... CC1P7550en
7 Boiler controller / load controller 22.05.2018
7.4 Control (characteristics)
The load controller can operate in 2 different operating modes:
∂ Modulating, or
∂ Multistage
With electronic fuel-air ratio control, modulating or multistage mode must be selected,
depending on the type of burner.
Parameter Operation Mode (Two-stage / Three-stage / Modulating)
7.4.1 Integrated 2-position controller (R = ON/OFF)
The integrated 2-position controller transmits to the burner control section the internal
information Heat request controller (R = ON/OFF).
Modulating mode:
R = ON when: Actual value ′ (setpoint ± SD_ModOn)
R = OFF when: Actual value > (setpoint + SD_ModOff)
Multistage mode:
R = ON when: Actual value ′ (setpoint ± SD_Stage1On)
R = OFF when: Actual value > (setpoint + SD_Stage1Off) or
R = OFF when: Actual value > (setpoint + SD_Stage3Off) = low-fire operation;
always applies if none of the 2 thresholds Q2 and Q3 has been
exceeded
Β
Note!
The following standards also have to be observed for multistage operating mode:
∂ SD_Stage3Off > SD_Stage1On
∂ SD_Stage3Off < SD_Stage2Off < SD_Stage1Off
Ι
Note!
When SD_*_On is positive, the switching differential lies above the setpoint. When
SD_*_On is negative, it lies below the setpoint (load controller software version V01.40
or higher).
Parameter SD_ModOn
SD_ModOff
SD_Stage1On
SD_Stage1Off
SD_Stage2Off
SD_Stage3Off
Operating mode
General
Switching differentials