Nowadays, electrical circuits and systems are the core of our daily comfort at home, from photovoltaic panels to telecommunications systems, such as radio and television.With its excellence and its over 30 years’ experience, ZOTUP is able to efficiently protect them from over-voltages.


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What are over-voltages?

For those who do not have a deep knowledge of the field, this term may seem meaningless, but the truth is that it plays a fundamental role when talking about electrical safety and protection. In any apparatus, circuit or plant, over-voltage refers to a level of electrical voltage that considerably exceeds one of normal operations. Over-voltages are due to numerous causes and they are generally divided into two categories depending on their source: over-voltages of “internal origin” and over-voltages of “external origin”. The former may arise because of system failures or certain manoeuvres while the latter are generated by atmospheric discharges on the supply line.


The most common causes of over-voltages of internal origins are:

  • over-excitation of alternators;
  • grounding of a conductor;
  • intermittent discharges between a conductor and the ground;
  • opening of a switch on an unladen live line;
  • excessive speed of the generators;
  • mono-phase inverse failure.

The repercussions of over-voltages of external origin can occur either with a direct contact (overvoltage conducted) or with an indirect contact (overvoltage induced). In order learn more about lightning, check out the article “what lightnings are and how to protect yourself.


The risks of over-voltages

When dealing with electricity, there is always a certain amount of risk that must be considered. In case of over-voltages specifically, it is fundamental to know that they lead to economic, health and environmental risks. Let us explain. Everything starts when a damaged machine or a plant stop working. Besides the economic burden regarding the fixing up, if the damage is not contained in time, it may cause a fire which not only can seriously devastate the environment, but it can also put lives in danger. The only way to avoid such inconveniences, which basically means to be able to protect yourself, is to implement preventive solutions.


Over-voltages protection: the discharges

Since their invention in the ‘50s, discharges have been the most economical and effective option to protect both domestic and corporate electrical systems and circuits. The cheapest and probably the best solution to protect them against surges is to install the surge arrestor or SPD - Surge Protection Device in an existing plant. Basically, the SPD function is to store and divert the electricity flowing in excess. This way, unloading on the ground the anomalous flow, it is possible to allow the plant or the circuit not to overload and maintain the correct voltage level.

Depending on their features, voltage surges are divided into three “test classes”:

  • Test class I: ideal for areas affected by frequent adverse weather phenomena, such as violent thunderstorms and lightning;
  • Test class II: complementary to the first type and capable of supporting over-voltages caused by maintenance work on the power line;
  • Test class III: to be installed after the first two variants directly in the back of an appliance socket to ensure additional protection.


According to their function, a SPD can be divided into three macro-categories:

  • Switching SPD: galvanically insulated and small; its two spaced electrodes (check isolating spark gap meters) reduce instantly the SPD impedance and thus the over-voltage, when the voltage exceeds a threshold limit;
  • Limiting SPD: thanks to varistors made of ceramic paste and zinc oxide particles, the SPDs have a gradually decreasing impedance when tension increases. This mechanism guarantees very short intervention times, precision in the repeatability of ignitions and absence of the subsequent current;
  • Combined SPD: produced in series or in parallel, they allow you to use the advantages of the two previous categories.


ZOTUP: Surge Protection Solutions

Founded in 1986, ZOTUP is a leader in the field of over-voltages. The Italian production of the company based in Bergamo offers products of high quality that guarantee total safety to its customers, their goods, and their working environment. Over the years, they kept innovating both their products, as demonstrated by the new technology of ZOTUP surge arresters, and their services, for example with the establishment of the ZOTUP AcademyThe main purpose of ZOTUP is to provide customers with maximum protection from over-voltages and developing products designed for public, corporate and private sectors.

The wide range of SPD products offered by ZOTUP covers a great variety of fields: from unloaders for wind turbines until public lighting, with a strong focus on the public sectors; then SPDs for data transmission and telecommunications networks, more spendable in the business sector; and also surge arresters for photovoltaic systems, useful to any citizen who has the roof of the house panelled.

Beyond the area of expertise, ZOTUP provides a technical support service to meet the needs of the customer and accompany him from the moment of the initial choice to the maintenance of the product installed. You can count on ZOTUP’s expertise and reliability for all your needs and feel protected from over-voltages.

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