Danfoss VLT AQUA Drive FC 200 Instruction Manual page 52

How to Install
In rare cases, very long control cables and analog signals
may, depending on installation, 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.
The digital and analog inputs and outputs must be
connected separately to the adjustable frequency drive
common inputs (terminal 20, 55, 39) to avoid ground
currents from both groups to affect other groups. For
example, switching on the digital input may disturb the
analog input signal.
Input polarity of control terminals
PNP (Source)
Digital input wiring
12 13 18 19 27
NPN (Sink)
Digital input wiring
12 13 18 19 27
VLT AQUA 12-Pulse High Power Instruction Manual
29 32 33 20 37
29 32 33 20 37
®
MG.20.Y1.22 - VLT is a registered Danfoss trademark
NOTE!
Control cables must be shielded/armored.
Connect the wires as described in the Instruction Manual
for the adjustable frequency drive. Remember to connect
the shields in a proper way to ensure optimum electrical
immunity.
4 4
4-21