Honeywell ACS-8, Installation Instructions Manual

Page: 21 / 142

Installation Instructions / ACS-8 21
1
The examples refer to the diagrams of chapter 5 “Important installation information”.
2
The examples refer to the diagrams of chapter 5 “Important installation information”.
6.5 Shielding or grounding of the module bus
(See also chapters 4 and 5)
Ground loops
Ground loops occur when the ground connection connects to one or more devices and then back to the
ground point again.
This would be the case if in chapter 5
example 3
1
the shielding is connected at each end of the cable.
Such loops must be avoided as they can generate very high circulating currents by way of the shorted
secondary transformer effect. Previously documented interference problems tend to be exacerbated in these
circumstances leading to damage to the circuitry and components.
Chapter 5 examples 1 to 6
2
show the correct connections.
If the shielding and grounding are connected in this way, loop currents are not induced since there is no
closed loop.
If the star principle of...
cabling all ground and shielding cables to a central ground point
...is observed, no ground loops are caused.