Table of Contents
Advertisement
Basics and mounting
Industrial security and installation guidelines > Installation guidelines
Isolation of conductors
40
Electrical, magnetically and electromagnetic interference fields are weakened by means
of an isolation, one talks of absorption. Via the isolation rail, that is connected conductive
with the rack, interference currents are shunt via cable isolation to the ground. Here you
have to make sure, that the connection to the protected earth conductor is impedance-
low, because otherwise the interference currents may appear as interference cause.
When isolating cables you have to regard the following:
n
If possible, use only cables with isolation tangle.
n
The hiding power of the isolation should be higher than 80%.
n
Normally you should always lay the isolation of cables on both sides. Only by means
of the both-sided connection of the isolation you achieve high quality interference
suppression in the higher frequency area. Only as exception you may also lay the iso-
lation one-sided. Then you only achieve the absorption of the lower frequencies. A
one-sided isolation connection may be convenient, if:
–
the conduction of a potential compensating line is not possible.
–
analog signals (some mV respectively µA) are transferred.
–
foil isolations (static isolations) are used.
n
With data lines always use metallic or metallised plugs for serial couplings. Fix the
isolation of the data line at the plug rack. Do not lay the isolation on the PIN 1 of the
plug bar!
n
At stationary operation it is convenient to strip the insulated cable interruption free
and lay it on the isolation/protected earth conductor line.
n
To fix the isolation tangles use cable clamps out of metal. The clamps must clasp the
isolation extensively and have well contact.
n
Lay the isolation on an isolation rail directly after the entry of the cable in the cabinet.
Lead the isolation further on to your PLC and don't lay it on there again!
CAUTION!
Please regard at installation!
At potential differences between the grounding points, there may be a
compensation current via the isolation connected at both sides.
Remedy: Potential compensation line
HB700 | CPU | PMC921xEx | en | 23-06
iC9200 Series
Advertisement
Table of Contents
