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Long control cables and analog signals may result in 50/60
Hz ground loops due to noise from line power supply
cables.
If ground loops occur, break the shield or insert a 100 nF
capacitor between shield and chassis, if needed.
Connect the digital and analog inputs and outputs to the
control cards of the units separately to avoid ground
currents. These connections are on terminals 20, 55, and 39
for both the filter and adjustable frequency drive sections.
12
13
18
19
27
29
32
33
20
37
+24
V DC
0
VDC
130
BT106.10
PNP (Source)
Digital input wiring
Figure 4.14 Input Polarity of Control Terminals, PNP
NPN (Sink)
Digital input wiring
12
13
18
19
27
29
32
33
20
37
+24
V DC
0
VDC
130
BT107.11
Figure 4.15 Input Polarity of Control Terminals, NPN
NOTICE!
To comply with EMC emission specifications, shielded/
armored cables are recommended. If using non-shielded/
armored cable, see
chapter 4.7.3 Power and Control Wiring
. If using non-shielded control
cables, use ferrite cores to improve EMC performance.
130B
T340.11
1
2
Figure 4.16 Connecting Shielded Cables
Connect the shields in a proper way to ensure optimum
electrical immunity.
4.8.5 Safe Torque Off (STO)
To run STO, additional wiring for the frequency converter is
required. Refer to
VLT
®
Frequency Converters Safe Torque Off
Operating Instructions
for further information.
Electrical Installation
VLT
®
AutomationDrive FC 302 Low Harmonic Drive
132–630 kW
46
Danfoss A/S © Rev. 04/2015 All rights reserved.
MG37A322
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