Load Output X74 Pin 3; Safe Separation Of Mains Voltage And Extra Low-Voltage; Modulating Operation; 2-Stage Operation - Siemens LMV36.520A1 Basic Documentation


Building Technologies Division
Infrastructure & Citiies Sector

14 Load output X74 pin 3

The load output is only available as an alternative to VSD control. If the VSD is
deactivated, the output for the VSD delivers the current burner output. The analog
output is a voltage output and – using parameter 645 – can be switched between DC
0...10 V, DC 2...10 V and DC 0/2...10 V.
Parameter 645 Voltage range
0 DC 0...10 V
1 DC 2...10 V
2 DC 0/2...10 V
Note
When changing the analog output configuration from DC 0...10 V to DC 2...10 V or
DC 0/2...10 V, the voltage values with modulating, 2-stage and 3-stage operation
change (refer to chapters Modulating operation, 2-stage operation and 3-stage
operation).
Conversion: New value = (initial value * 0.8) + 2
Initially 2 V  (2 * 0.8) + 2 = 3.6 V
Example:
Initially 5 V  (5 * 0.8) + 2 = 6 V
14.1 Safe separation of mains voltage and extra
low-voltage
Caution!
The load output is designed for SELV or PELV (refer to chapter Electrical
connection of the LMV36... and AGM60...).
For this reason, strict separation from the mains voltage side must be ensured!
This necessitates power supply by an external power pack (X74 pin 1, X74 pin 2).

14.2 Modulating operation

Actual value Voltage
Off DC 0 V
Ignition load DC 1 V
Low-fire DC 2 V
High-fire DC 10 V
The values between low-fire and high-fire are interpolated in a linear manner.

14.3 2-stage operation

Actual value Voltage
Off DC 0 V
Stage 1 DC 5 V
Stage 2 DC 10 V
Basic documentation LMV36...
14 Load output X74 pin 3
Remarks
No detection of line interruption
Detection of line interruption
possible
No detection of line interruption.
Recommended setting in
connection with Micromaster VSD
Curvepoint Display / output
value
--- Off
P0 10%
P1 20%
P9 100%
Curvepoint Display / output
value
--- Off
P1 P1
P2 P2
143/248
CC1P7544en
25.09.2013