29
2.2 Industrial Security and Installation Guidelines
via cable isolation to the ground. Here you have to make sure, that the connection to the protected earth conduc-
tor is impedance-low, because otherwise the interference currents may appear as interference cause.
When isolating cables you have to regard the following:
• If possible, use only cables with isolation tangle.
• The hiding power of the isolation should be higher than 80%.
• Normally you should always lay the isolation of cables on both sides. Only by means of the both-sided connec-
tion of the isolation you achieve high quality interference suppression in the higher frequency area. Only as
exception you may also lay the isolation one-sided. Then you only achieve the absorption of the lower frequen-
cies. 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.
• With data lines always use metallic or metallized 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!
• At stationary operation it is convenient to strip the insulated cable interruption free and lay it on the isolation/
protected earth conductor line.
• To fix the isolation tangles use cable clamps out of metal. The clamps must clasp the isolation extensively and
have well contact.
• Lay the isolation on an isolation rail directly after the entry of the cable in the cabinet.
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
2
Overview
To Next Page
Loading...
