Siemens LMV36.520A1 - VSD and PWM Fan Control Details

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Building Technologies Division Basic documentation LMV36... CC1P7544en
Infrastructure & Citiies Sector 13 Fan control 25.09.2013
13.3 VSD control X74 pin 3
The VSD is controlled via a voltage interface (refer to chapter Load output X74 pin 3)!
Depending on the type of VSD used, a release contact is required. This contact can be
controlled via the fan motor contactor. To enable the VSD to bring the fan motor’s speed
to the correct no-load speed, the motor contactor’s drop out delay time must be about
25 seconds.
Example:
K1
9
5
3
4
+24 V
+
Setpoint 0...10 V
Siemens Micromaster 440
K1
28
Figure 82: Connection of VSD to the LMV36
It is possible to set the VSD control to 0 via the analog output when the safety loop is
open (including burner flange switch).
This may be necessary if the no-load speed is not 0.
No. Parameter
652 VSD behavior when safety loop / burner flange is open
0 = no VSD control when safety loop / burner flange is open
1 = VSD control independent of safety loop / burner flange