Danfoss VLT FC 102 Operating Instructions Manual page 108

6 How to Programme the Low Harmonic Drive
[139] Bus ctrl.
[140] Bus ctrl. 4-20 mA
[141] Bus ctrl t.o.
[142] Bus ctrl t.o. 4-20mA
[143] Ext. CL 1 4-20mA
[144] Ext. CL 2 4-20mA
[145] Ext. CL 3 4-20mA
NB!
Values for setting the Minimum Reference is found in open loop par. 3-02
Feedb. - values for maximum reference for open loop is found in par. 3-03 Maximum Reference and for closed loop par. 20-14 Maximum Reference/
Feedb. .
6-51 Terminal 42 Output Min Scale
6
Range:
0.00 %* [0.00 - 200.00 %]
6-52 Terminal 42 Output Max Scale
Range:
100.00 %* [0.00 - 200.00 %]
EXAMPLE 1:
Variable value= OUTPUT FREQUENCY, range = 0-100 Hz
Range needed for output = 0-50 Hz
Output signal 0 or 4 mA is needed at 0 Hz (0% of range) - set par. 6-51
Output signal 20 mA is needed at 50 Hz (50% of range) - set par. 6-52
108
0 - 100%, (0-20 mA)
0 - 100%
0 - 100%, (0-20 mA)
0 - 100%
0 - 100%
0 - 100%
0 - 100%
Minimum Reference and for closed loop par. 20-13 Minimum Reference/
Function:
Scale for the minimum output (0 or 4 mA) of the analogue signal at terminal 42.
Set the value to be the percentage of the full range of the variable selected in par. 6-50
42 Output .
Function:
Scale for the maximum output (20 mA) of the analog signal at terminal 42.
Set the value to be the percentage of the full range of the variable selected in par. 6-50
42 Output .
It is possible to get a value lower than 20 mA at full scale by programming values >100% by using
a formula as follows:
mA / desired maximum current × 100 %
20
mA
20
i . e . 10 mA :
× 100 % = 200 %
10 mA
Terminal 42 Output Min Scale to 0%
Terminal 42 Output Max Scale to 50%
®
MG.16.A1.02 - VLT is a registered Danfoss trademark
VLT HVAC Low Harmonic Drive Operating In-
structions
Terminal
Terminal