14.3.1.1
Atmospheric discharge (lightning)
Atmospheric discharge can take place directly or indirectly on power and com-
munication lines. The consequence of such an impact if there is insufficient
protection is the destruction of the electrical device.
Atmospheric discharge is simulated in accordance with the international test
standard IEC 61000-4-5 (EN 61000-4-5 for Europe) – "Electromagnetic com-
patibility (EMC). Testing and measurement techniques. Surge immunity test".
The relevant international product standard for control systems, IEC61131-2
(EN61131-2 for Europe), divides the areas of application into zones. Higher or
lower levels of interference can be expected depending on the zone in ques-
tion. All Kemro-K2 control systems and also the products of the KeTop range
are suitable for application in Zone B.
The product standard requires the testing of surge immunity in accordance with
IEC 61000-4-5.
14.3.1.2
Electrostatic discharge (ESD)
Materials can be charged by contact followed by subsequent separation. This
effect only arises when at least one of the two materials is a non-conductor.
As a result, discharge may take place if a charged conductor, or one that is
changed by the influence of an electronic field, comes near a metallic object.
After charging, the possible voltages between the charged bodies can reach
over 10 kV.
The most frequent occurrence of electrostatic discharge takes place between
people and metallic objects. Since one is practically unnoticed of discharges
below 3500 V and yet electronic components are destroyed by low voltages,
ESD damage to electronic components often goes unnoticed.
The international Standard IEC 61000-4-2 (EN 61000-4-2 for Europe) is used
to simulate the measurement of electrostatic discharge. The international
product standard IEC 61131-2 (EN 61131-2 in Europe) for programmable con-
trols demands testing to IEC 61000-4-2 and also defines the severity level.
14.3.1.3
Technical systems as interference sources
Technical systems can act as sources of interference. In doing so, the inter-
ference may be intentional or unintentional. Electromechanical energy is often
also used for material processing.
Periodically occurring interference:
●
Ignition impulses of combustion engines
●
Sparking of commutator motors
●
Electromagnetic fields of induction furnaces, arc welding device, micro-
wave device etc.
●
Pulse currents from frequency converters and switching power supplies
●
Electromagnetic fields of radio and telecommunications device
Randomly occurring interference:
CE Conformity, Directives and Standards
© KEBA 2009
User's Manual V1.50
143
Summary of Contents for KeTop T100
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