Specifications

28
Schneider Electric
Implementation guidelines (continued)
b Separate analogue and digital signals with a row of 0 V pins if they use the same
connector.
b Protection with a factor of approximately 5 with high frequencies can be obtained
if rule number 5 is followed.
b Power outputs of variable speed drives must always be shielded or filtered.
Internal cabling of cabinets
Digital control devices, variable speed drives and PLCs can be placed in the same
cabinet if:
b Variable speed drives are installed with shielded cables.
b All the above cabling guidelines are followed.
Recommendations:
b Use the enclosure as a Faraday shield.
b Limit the number and size of openings in enclosure panels.
b Avoid inside partitioning of enclosures, which increases electromagnetic
interference.
b Attach devices to plates made of non-insulating materials that act as grounding
planes.
b Place all equipment on a grid at the back of the cabinet.
Definition: A Faraday cage is a conducting envelope with perfectly joined walls.
Rule no. 4:
The same connector should not be used
for different types of connections (except
for relay and power circuits).
Rule no. 5:
All free conductors in a cable should
systematically be connected to chassis
ground at both ends (except for analogue
cables).
Rule no. 6:
Power cables do not need to be shielded if
they are filtered.
Inside partitioning of enclosures increases
electromagnetic interference.
Note: all attachments should make
electrical contact => scratch the paint.
E52301
Safety conductors
Ground bar
Equipotential grid:
DIN rail + cabinet ground
Mounted with
electrical contact
(fan type washer)
Cabling Guidelines