Control (Characteristics); Operating Mode; Integrated 2-Position Controller (C = On / Off); General - Siemens LMV51 Series Basic Documentation

Operating mode

General

Switching differentials

Siemens Building Technologies
HVAC Products

5.4 Control (characteristics)

The load controller can work 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)

5.4.1 Integrated 2-position controller (C = ON / OFF)

The integrated 2-position controller transmits to the burner control section the internal
information «Heat demand controller» (C = ON / OFF).
Modulating mode:
Actual value £ (setpoint ± SD_ModOn)
C = ON when:
C = OFF when: Actual value > (setpoint + SD_ModOff)
Multistage mode:
Actual value £ (setpoint ± SD_Stage1On)
C = ON when:
C = OFF when: Actual value > (setpoint + SD_Stage1Off) or
C = OFF when: Actual value > (setpoint + SD_Stage3Off) = low-fire; always applies if
none of the 2 thresholds Q2 or Q3 has been exceeded
Note: When «SD_*_On» is positive, the switching differential lies above the setpoint.
When«SD_*_On» is negative, the switching differential lies below the setpoint
(from software version V01.40).
Parameters: SD_ModOn
SD_ModOff
SD_Stage1On
SD_Stage1Off
SD_Stage2Off
SD_Stage3Off
Basic Documentation LMV51...
5 Temperature or pressure controller (internal load controller LC)
61/157
CC1P7550en
29.05.2002