In the last decades of the nineteenth century the so-called “War of the currents” took place, a sort of epic no-holds-barred commercial competition that saw two different visions about the use of electric current, supported, on opposite sides, by two great geniuses of the humanity: Thomas Alva Edison (who argued the benefits of using direct current) and Nikola Tesla (who argued instead the benefits of alternating current). Tesla’s vision prevailed, above all for the possibility of easily making transformers capable of increasing or lowering the grid voltage, and therefore of minimizing losses on the cables, and for more than a hundred years alternating current (AC) has been the main option for all energy distribution systems.
Today, however, the idea that direct current (DC) can instead be considered as a valid and efficient system for managing electricity is gaining ground. In fact, the great growth of renewable energies, in particular photovoltaic and wind power (decentralized direct current energy sources), together with the growth of the storage solutions market, is also increasing interest in energy networks. direct current distribution, which would make it possible to avoid conversion losses from alternating to direct current and would allow a simpler integration of renewable sources and energy storage systems. The direct current would also allow to obtain great advantages also in energy efficiency, and especially in production sector.
All this makes it essential to ensure that direct current applications do not become a risk for the safety of people, machines and systems themselves, and therefore that they are adequately protected against overcurrents, in particular against short circuits.
Italweber is closely monitoring the evolution of the situation, actively participates, within the international technical committees, in the study of specific solutions for the protection of equipment operating in direct current and, in recent years, has designed and manufactured various product lines, in particular fuses and relative fuseholders, expressly dedicated to the protection of this type of applications.
Here are the series of products developed for the protection of direct current applications.
- Cylindrical fuses and blade type fuses for the protection of the strings in photovoltaic plants, with gPV time-current characteristic, 1500 DC and rated currents up to 500A; ability to remotely monitor the intervention through special signaling devices;
- switch disconnectors in DC-22B to operate in complete safety in direct current, with voltages up to 1500V DC and currents up to 1250A;
- surger arresters, Class I and II for the protection of direct current applications (typically used in PV systems) with voltages up to 1500V DC;
- fuses dedicated to battery protection, so-called “battery fuses”, designed with a special characteristic curve called gBAT, available in cylindrical or blade type format, with voltages up to 1500V DC and currents up to 630A;
- high speed fuses for screw fixing for the protection of industrial equipment operating in direct current DC drives, power converters, etc. with voltages up to 850V DC and currents up to 1100A;
- Fuses for the protection of telecommunications equipment, with voltage 80V DC and currents up to 800A in the NH-00 size;
- Cylindrical fuses with screw connection for the protection of fuel cells, with rated currents from 4A to 20A and rated voltage 450V DC;
- Fuses for battery powered equipment, specific for the protection of forklift batteries, with voltage 48V DC;
- Automotive fuses for cars, trucks, campers, etc, with voltages 32V DC and currents up to 80A.