Danfoss vlt fc 300 Instruction Manual page 54

®
VLT Automation Drive FC 300 12-Pulse
How to Install
Instruction Manual High Power
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 29 32 33 20 37
Figure 3.43
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NPN (Sink)
Digital input wiring
12 13 18 19 27 29 32 33 20 37
Figure 3.44
NOTE!
Control cables must be shielded/armored.
Figure 3.45
® Automa-
Connect the wires as described in the VLT
tionDrive FC 300 Instruction Manual, MG33AXYY. Remember
to connect the shields in a proper way to ensure optimum
electrical immunity.
3-45
3 3