A new system for the protection of mobile telephone network equipment and FM-TV relay stations.

On account of the implementation of GSM and 3G networks, BTS plants are more and more often installed in areas where the quality of the electrical supply is quite bad. Such unfavourable conditions affect both vast regions of the developing countries, and the mountainous areas and rural districts of the developed countries.

If we take into account the high costs deriving from plant failures and, above all, the missed revenues due to service interruption, we understand that the continuity of operation is as important as the safety of the operators working on the plants.

The experience on field has shown that atmospheric discharges are the first and most important danger for plants operation.

It has been observed that the plants situated within a range of 1.5 km from the lightning impact point are subject to over-voltages due to the capacitive coupling originating between the electromagnetic fields and the wire which the plants themselves are connected to.

The new integrated power supply model AI333-20E/EXC has been purposely designed for solving some of the problems deriving from the above mentioned phenomenon.

As a matter of fact, the integrated power supply AI333-20E/EXC protects mobile telephone network equipment and FM-TV relay stations from the over currents and over voltages generated by atmospheric discharges.

Our product is the result of laboratory tests and of countless years of use in sites exposed to lightning. As a matter of fact, in the field of broadcasting, where the same technology has been used for several years, end users have noticed a heavy reduction in the number of failures in comparison with AM/FM relay stations protected by traditional devices.

Moreover, thanks to its isolation transformer, our integrated power supply assures the galvanic separation of the distribution lines from the telephone plant and of the auxiliary equipment.

Therefore, the use of the integrated power supply AI333-20E/EXC:

• increases the continuity of operation of the station;
• allows a more rapid and economic technical assistance;
• helps to reduce the operating costs.

All changes for adapting the equipment to the specific requirements of each mobile telephone operator can be made on demand.

The most peculiar components of the equipment are two spark-gap magnetic blow-out lightning arresters

They combine the advantages of lightning arresters with those of classic spar-gaps. Their most important features are:

• high precision striking voltage with any overvoltage waveform;
• immediate restoration of the plant normal operating conditions by the interruption of the arc current at its first zero-crossing after the exhaustion of the overvoltage wave;
• capability of withstanding currents with peak value of 100 kA (10/350 µs), charge of 80 As and specific energy of 1,25 MJ/O;
• auto-regenerability. Thanks to this characteristic, the arrester does not need to be replaced, as it happens with other overvoltage protection systems.