108/213
Building Technologies Basic documentation LMV37.4... CC1P7546en
HVAC Products 12 Power output X74.3 01.12.2009
12 Power output X74.3
The power output is only available as an alternative to VSD control. If the VSD is deacti-
vated, 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 Remarks
0 0…10 V No detection of open-circuit
1 2…10 V Detection of open-circuit possible
2 0 / 2…10 V No detection of open-circuit
Recommended setting in connec-
tion with Micro master VSD
&
Note
When changing the analog output configuration from 0…10 V to 2…10 V or 0 / 2…10
V, the voltage values with modulating, 2-stage and 3-stage operation change (refer to
section Modulating operation, section 2-stage operation and section 3-stage opera-
tion).
Conversion: New value = (initial value * 0.8) + 2
Example: Initially 2 V
→ (2 * 0.8) + 2 = 3.6 V
Initially 5 V
→ (5 * 0.8) + 2 = 6 V
12.1 Safe separation of mains voltage and extra
low-voltage
Caution!
The power output is designed for SELV or PELV (refer to section «Electrical
connection of LMV37.4...»).
For this reason, strict separation from the mains voltage side must be ensured!
This necessitates power supply by an external power pack (X74.1, X74.2).
12.2 Modulating operation
Actual value Voltage Curvepoint Display / output val-
ue
Off 0 V --- Off
Ignition load 1 V P0 10%
Low-fire 2 V P1 20%
High-fire 10 V P9 100%
The values between low-fire and high-fire are interpolated in a linear manner.
12.3 2-stage operation
Actual value Voltage Curvepoint Display / output
value
Off 0 V --- Off
Stage 1 5 V P1 P1
Stage 2 10 V P2 P2
To Next Page
Loading...
