Input Polarity Of Control Terminals; Grounding Of Shielded/Armored Control Cables; Start/Stop - Danfoss VLT Midi Drive FC 280 Programming Manual

Introduction
1 1
In rare cases, long control cables and analog signals result
in 50/60 Hz ground loops due to noise from mains supply
cables. If this occurs, 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 55) of the
frequency converter to avoid that ground currents from
both groups affect other groups. For example, switching
on the digital input could disturb the analog input signal.

Input polarity of control terminals

12 13
Illustration 1.3 PNP (Source)
12 13
Illustration 1.4 NPN (Sink)
NOTICE
Control cables must be shielded/armored.
8
VLT
PNP (Source)
Digital input wiring
18 19 27 29 32 33
NPN (Sink)
Digital input wiring
18 19 27 29 32 33
Danfoss A/S © 07/2016 All rights reserved.
®
Midi Drive FC 280
See the section Using Shielded Control Cables in the design
guide for the correct termination of control cables.
55
Illustration 1.5 Grounding of Shielded/Armored Control Cables

1.3.2 Start/Stop

Terminal 18 = Parameter 5-10 Terminal 18 Digital Input [8]
Start.
Terminal 27 = Parameter 5-12 Terminal 27 Digital Input [0]
No operation (Default coast inverse).
55
Speed
Start/Stop
[18]
Illustration 1.6 Start/Stop
12 13 18 19 27 29 32 33
Start/Stop
MG07C302