Danfoss VLT AutomationDrive FC 300 Design Manual page 229

Electrical Installation
Figure 7.44 Interconnect Diagram, E- and F-Frame Adjustable Frequency Drives
Very long control cables and analog signals may result in 50/60 Hz ground loops due to noise from line power supply
cables. If this occurs, it may be necessary to break the shield or insert a 100 nF capacitor between shield and chassis.
Connect the digital and analog inputs and outputs separately to the common inputs (terminal 20, 55, 39) of the adjustable
frequency drive to avoid ground currents from both groups affecting other groups. For example, switching on the digital
input may disturb the analog input signal.
MG34S222
Design Guide
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
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