Overview

Here are some practical examples of how the protective measures described are carried out and how the protective devices introduced are used in electrical systems with sensitive electronic equipment. These are also systems which were seriously interfered with or even damaged by lightning previously. Since protective measures were completed the well-targeted application of protective devices has been working trouble-free for years, even during violent thunderstorms and direct lightning strikes.

It is now over 20 years since the development of surge limiters for highly sensitive electronic systems was initiated. At that time structures were equipped with the new protective devices and with 'lightning current counters'. Today, there is more than a decade of reliable information on the efficiency of these surge protective devices, including those systems that failed five times and more per year in the previously unprotected stage.

A lightning/surge current counter which can also register the response of surge protective devices is shown in Figure 6 a. This is designed according to the current transformer principle (Figure 6 b) and registers surge currents with peak values exceeding 200 A. Such a counter can be installed directly into the down conductor of a lightning protection system (Figure 6 c) or the earth bonding line of a protective device without reducing the cross section. Often it is necessary to carry out surge voltage/surge current tests not only in the laboratory or during the production of protective devices but also in the field. Here the portable 'hybrid generator' shown in Figure...