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Why surge protection?

External lightning protection alone cannot provide complete safety.
It only protects against fire and other damage to the building. But it cannot prevent destroying power from a nearby lightning strike get into the house via electric mains. This may damage electronic devices or cause smouldering fires.

Another typical cause for disfunction of electronic devices and information technology systems are switching operations in the power supply network. Again you can protect yourself by using DEHN products.

Remember that the most aggravating danger concerns not only households but also companies which are dependent on fully functioning technical systems. Powerful information networks are the backbone of our modern industrial society.
Failures of such systems may cause severe damage and losses or may even lead to a company's bancruptcy.

The cause for disturbances of those information technology systems are multifarious. Reports of electronic Insurance companie's show alarming numbers: More than 30% of the damage have been caused by electromagnetic interferences.

The "Regulations on Electromagnetic Compatibility of Equipment (EMC Regulations)" came into effect on January 1st 1996. They contain provisions for trouble-free operation of electrical and electronic systems.
The current state of the art permits effective protection measures for installations and systems against the effects of lightning discharges and surges due to different causes.

Lightning Current Arresters / Surge Arresters

According to their different tasks the protective devices are divided into "Lightning Current Arresters" and "Surge Arresters".
In order to maintain complete protection in the field of surges have to be taken into consideration "Power Supply Systems" as well as "Information Technology Systems".

Yellow/Line · Surge protection - IT-Network

Surge protective devices for information technology systems
Failure of telephone, fax, computer or even complex computer controlled systems and machines is a risk too high to accept.
A percentage of more than 25% of the damage in information technology systems is caused by surge voltages due to electromagnetic interferences.

Protect your systems!

Protection Device Quick Selection by using coordination characteristics (KK):
When choosing the surge protection device take a voltage protection level UP which is below the surge immunity level of the terminal equipment installed downstream in the communication/signalling circuit.
Since this level is often unknown it is necessary to use other means of comparison instead.
According to tests for electromagnetic compatibility (EMC), electrical and electronic equipment must have a certain immunity level against line-conducted disturbances (surges). The test set-up and the requirements for testing are stipulated in EN 61000-4-5 (VDE 0847 Part 5).
Installation classifications from 0 to X stand for certain electromagnetic environmental conditions. Depending on these installation classifications, different immunity levels (1-4) of the equipment are determined regarding the immunity against surges.
An equipment tested according to the test level 1 has the lowest surge immunity and equipment tested according to level 4 has the highest surge immunity. The test level is normally indicated in the specification of the equipment or can be inquired with the manufacturer.
With regard to the protection provided by the surge protective device this means that the let-through energy must be below the immunity level of the equipment to be protected.

Coordination characteristics (KK)

XX/XThe first mark (here XX) gives information about the let-through energy of the surge protective device, the second mark (here X) about the required surge immunity level of downstream equipment or the let-through energy of another downstream surge protective device.
The coordination characteristics decribe the let-through energy of the surge protection device and the required surge immunity level of downstream equipment (or the let-through energy of another downstream surge protective device).
For a trouble-free operation, the indicated test level of terminal equipment (e.g.) 3 must be higher than or similar to the test level demanded by the coordination characteristics of the protective device (e.g. 1, 2 or 3)

Use of combined surge arrester