Novexx Solutions ALS 30 Series, Руководство по установке

Страница: 8 / 59

Installation Manual
ALS 30x
02/2016 | 00 8 Please observe the following
Rules for electromagnetic compatibility
Connect all metallic parts to each other via large surfaces, ensuring electric conductivity.
– Only polished metal surfaces are electrically conductive. Painted or oxidised surfaces are unsui-
table. Aluminium which appears to be polished still has an invisible oxidation layer on the surfa-
ce.
– Coated or plated surfaces, though electrically conductive, can reach very high resistance values
at high frequencies (skin effect).
 Clean contact surfaces, polish the metal, use fan disks (washers) or mounting plates.
 Carry out EMC grounding, preferably as a neutral (star) point. A neutral (star) point prevents lo-
ops.
When laying the signal lines and power cable, space them apart.
 Lay all control and signal lines at least 50 cm distant from power cables (e.g. motor line). Mini-
mum distance in the switch cabinet: 20 cm.
 Spatially lay out all the lines in the switch cabinet as close as possible to the reference potential.
Lead the signal lines into the unit or switch cabinet from one side only.
– The more lines that are laid in front and in back between the switch cabinet and the machine,
the larger the radiation surface of the radiated electromagnetic energy.
 Lead the signal lines out of the machine (in one bundle and from one location, if possible) and
into the switch cabinet.
Twist together unshielded lines from the same circuit.
– This reduces interference effects of various kinds.
Wire inductive components to suitable interference suppressors.
– Possible inductive components: Relay, solenoid valve
– Possible interference suppressors: Diodes, varistors, RC combinations
 House all components suspected of being sources of RF interference fields in a closed metal
casing (Faraday screen).
Shield all signal and control lines.
 Ground the shielding on both sides at its large surfaces.
 For insufficient potential equalisation between the shielding lines: Lay an additional equalisation
lead parallel to the shielding with a cross section at least 10 mm
2
.
Avoid equalisation currents in the shielding of the signal lines
– Equalisation currents can arise between subassemblies with different grounding conditions.
 When the grounding conditions are different, only shield the side with the better grounding con-
dition.
 Only shield both sides when the grounding conditions are the same (e.g. inside a machine).