Safe Torque Off (Sto); Additional Connections; Serial Communication - Danfoss VLT HVAC Drive FC 102 Operating Instructions Manual

Electrical Installation
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.
PNP (Source)
Digital input wiring
12 13 18 19 27
Figure 4.13 Input Polarity of Control Terminals, PNP
NPN (Sink)
Digital input wiring
12 13 18 19 27
Figure 4.14 Input Polarity of Control Terminals, NPN
MG16I322
Operating Instructions
29 32 33 20 37
29 32 33 20 37
Danfoss A/S © 04/2015 All rights reserved.
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
for Non-shielded Cables. If using non-shielded control
cables, use ferrite cores to improve EMC performance.
1
Figure 4.15 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.

4.9 Additional Connections

4.9.1 Serial Communication

RS-485 is a 2-wire bus interface compatible with multi-drop
network topology, i.e., nodes can be connected as a bus,
or via drop cables from a common trunk line. A total of 32
nodes can be connected to one network segment.
Repeaters divide network
2
45
4 4