The EMC Connection!!!

EMC cable glands.

AGRO cable glands for interference-free cable installations.

EMC. : A topic with serious consequences.

Electromagnetic compatibility (EMC) is something that everyone in our modern world is confronted with. For instance, if a bothersome tone in the radio alerts you that your mobile phone is ringing, this is a typical case of an electromagnetic interaction between two pieces of equipment.In this context, disturbing noises are only the most harmless consequences of such unwanted interactions. When your expensive high-tech car won’t move because of electromagnetic incompatibilities in the on-board computer, things become much more upsetting and expensive. This topic takes on a whole new meaning when the functions of entire industrial plants or rail vehicles are disrupted or even brought to a standstill because of EMC problems. The financial damages due to a manufacturing outage can quickly reach enormous amounts in the 5- to 7-digit Euro range – not to speak of possible loss of data or damage to the company’s image arising from delayed deliveries.

As our everyday lives and businesses tend to increasingly rely on technology, the issue of EMC continually gains added importance. More and more electronic devices are being used in the home, industrial plants
are becoming more complex, and it’s hard to imagine life without new wireless technologies such as GPS, Bluetooth or WLANs. Just as the electronics industry is growing, so too is the level of electromagnetic interference because basically every piece of electrical equipment is susceptible to EMC or itself even creates such interference. Achieving 100 percent electromagnetic compatibility is nothing more than wishful thinking. In fact, it has become mandatory to address EMC aspects early in the planning and development phases of machines, systems and equipment and in doing so include all relevant components. In this way, expensive rework can be avoided. Specifically, statistics indicate that almost 40 percent of all
electronic failures can be traced back to insufficient EMC measures.

Standards and regulations.

EMC directives.

What, exactly, is EMC? Every electrical device generates an electromagnetic field around itself, and this field in turn can induce currents and voltages in other electrical devices. Depending on the intensity of the mutual coupling, this effect can lead to malfunctions, reduced functionality or even total failure of the equipment.

In European Standard EN 61000, the term EMC is defined as follows:
Electromagnetic compatibility is the ability of a piece of electrical equipment to function satisfactorily in an electromagnetic environment without influencing this same environment, in which other equipment is located,
more than is permitted. The active and passive aspects of this definition can be more clearly illustrated with the example of a pacemaker. The operation of such a pacemaker should not in the least be compromised by
environmental influences to ensure that the patient’s life is not put in danger. On the other hand, the patient himself must not be harmed by the operation of the device itself.

Basically, a distinction is drawn between electromagnetic influences in the low-frequency and high-frequency regions. In the lowfrequency region, interference arises due to the various forms of coupling (galvanic, inductive, capacitive) between two electrical circuits. In the high frequency region starting at 10 kHz and above, in contrast, there are additional field-related coupling effects that have an effect on susceptible equipment, which can act as a sink for the interference – in other words, on receivers, electrotechnical equipment or electrical systems. Furthermore, there is a distinction between natural sources of interference such as lightning and artificial causes such as TV and radio transmitters, frequency converters and switching operations.

When it comes to EMC, not only technical issues are of interest but also legal aspects. In general, electrical products, machines and systems are subject to various directives, laws, ordinances and regulations. The legal provisions applicable to EMC at the European level are intended to guarantee not only free movement of goods within the domestic markets but also to ensure the protection of health and safety for people as well as to protect the environment, radio operations and consumers. Therefore,within the EU, only those products can be brought to market which meet the protection regulations established in the EMC Directive (2004/108/EC). Accordingly, manufactures must design their products such that no unacceptable electromagnetic interference arises between two devices or systems, and this is to be verified with corresponding test procedures and the confirmation made visible with a CE marking.

The most important things for interference-free operation: Shielding and contact.

In the industrial sector, EMC plays a particularly key role because complex machines and systems are extremely susceptible to electromagnetic interference. Such undesired EMC effects, however, can be counteracted with the effective shielding of all components. On the one hand, good shielding reduces the amount of interference emitted by an electrical apparatus while at the same time reducing its susceptibility to impaired performance due to electromagnetic effects.

Not only cables themselves but also all other components that are part of
the installation must provide shielding characteristics. As passive components, cable glands must ensure that the quality of the shielding at sensitive interconnection points remains intact and that there are no losses due
to the shielding. For this reason, it’s necessary to not only use a maximally shielded cable but also add EMC-compliant cable glands. Although there is no separate EMC standard for these components, they play a large contribution towards making it possible to meet the EMC characteristics prescribed by manufacturers.

The effect of cable shielding depends on the shielding material, the type of shielding and the connection to electrical ground. In order to achieve optimal effectiveness, the shielding must be connected on both
sides of ground through a connection with both low resistivity and low inductance. In other words, it must be led to the chassis wall through the shortest possible route and with a large contact surface. When subject to
vibrations, a good contact must not result in an increased transfer resistance. In practice, these requirements can only be fulfilled if the connection can be installed simply and without special tools.

With four different EMC-compatible cable glands, AGRO offers its customers the appropriate product and the ideal types of contact for each type of application. With the new Progress EMC easyCONNECT Brass cable gland , contact is established through an innovative spring clip. 

Furthermore, AGRO offers the following proven series of products:
• Progress EMC Rapid Brass
• Progress EMC Brass
• Progress Series 85 Brass

All these product lines stand out due to their easy assembly. Furthermore, the renowned Swiss EMC laboratory MONTENA EMC SA has certified AGRO cable glands for lowest transfer impedance and high current carrying capacity. Both are established criteria for the quality of shielding. In order to achieve a top grade, AGRO involves EMC specialists from the very beginning of new-product development.

To get more details on the products or to select the right product for your application, do write to us on info@hensel-electric.in