Mersen fuses and surge protectors are used in industrial switchgear, photovoltaic inverters, energy storage systems, and railway rolling stock circuits. DC circuits present particular challenges in fuse selection, as the arc is not extinguished at the natural current zero crossing – incorrect matching leads to damage of connected semiconductor devices. ELTRON distributes Mersen products throughout Poland and provides technical support in their selection.

Company Profile and Scale

Mersen is an international group with over 130 years of history (known as Carbone Lorraine until 2010), listed on Euronext Paris. In 2025, the group's revenues reached nearly €1.2 billion with approximately 7,260 employees. The group operates over 50 manufacturing facilities and 24 R&D centres in 32 countries. Close to 60% of sales come from markets related to the energy transition.

The group operates through two segments. The Advanced Materials segment produces isostatic graphite, silicon carbide, carbon fibre insulation, carbon-carbon composites, and brushes and brush holders used in, among others, aerospace and space technology. The Electrical Power segment covers circuit protection, power electronics, semiconductor cooling, laminated busbars, and current collection systems for rail. The combination of materials and electrical expertise sets Mersen apart from manufacturers specialising solely in fuses.

Protection Against Short Circuits, Overloads, and Overvoltages – AC and DC

The core of Mersen's offer consists of fuses with a strong current-limiting effect. Fuse links with gG, gM, and aM characteristics protect low-voltage installations against the effects of short circuits and, to a limited extent, overloads. Protection against atmospheric and switching overvoltages is provided by Surge-Trap surge protectors in Type 1, Type 2, and Type 1+2 variants. Both product groups are available in AC and DC versions.

In photovoltaic installations, selection is carried out for string voltages of 1,000 V and 1,500 V DC – for these applications, HelioProtection fuses and Surge-Trap arresters are available. In AC switchgear, NH blade fuses and cylindrical fuses with gG characteristics are used. Effective protection requires coordination of both protection levels – short-circuit current limitation and overvoltage limitation – rather than selecting individual components in isolation.

Fast Fuses and DC Versions

In the field of fast (semiconductor) fuses and DC versions, Mersen is among the world's leading manufacturers. Protistor fuse links with aR and gR characteristics operate in microseconds and feature a low I²t Joule integral, protecting diodes, thyristors, IGBT modules, and silicon carbide (SiC) devices from exceeding their thermal energy limits.

For DC circuits with a high L/R time constant, versions rated up to 1,500 V (photovoltaics, energy storage) and Square Body versions rated up to 4,200 V DC for traction are available. In electrochemical energy storage systems (BESS), these properties are of fundamental importance. Arc extinction and short-circuit current interruption in a DC circuit with high inductance are more demanding than in AC circuits. Incorrect selection at this stage results in failure to interrupt the arc. A dedicated ABAT13 series is available for megawatt-class fast-charging stations (MCS) and energy storage applications.

Rail, Defence, and Energy

Mersen traction fuses, complying with the requirements of IEC 60077 among others, protect main and auxiliary circuits of railway rolling stock, while the Advanced Materials segment supplies current collection systems including carbon pantograph strips and brushes. Proven high-voltage DC designs and high mechanical robustness are key selection criteria in defence and marine applications, where the consequences of protection failure are particularly severe.

Power Distribution and Low-Voltage Equipment

In the field of power distribution, Mersen offers NH blade fuses (gG/gM/aM characteristics, sizes 000 to 4a) and cylindrical fuses ranging from 10×38 to 22×58 mm. These are complemented by fuse switches: vertical bar-type disconnectors (Multivert/Pro Grid) for busbar mounting, cover-mounted bases and disconnectors (Multibloc), as well as Modulostar and UltraSafe holders and gG fuse links for the D system. A complete protection and distribution path – from fuse link through base to bar-type and cover-type disconnector – can be assembled from a single manufacturer's products.

ELTRON – Mersen Distributor and Technical Partner

ELTRON has been distributing Mersen (formerly Ferraz) products since 1999 – for over 25 years. The company maintains a stock of blade, cylindrical, and semiconductor fuses, which shortens delivery times both in emergency situations and during the prototyping phase.

Technical support covers short-circuit protection coordination in DC circuits with a high L/R time constant, selection of fuse characteristics based on load type (resistive, motor, capacitive, semiconductor), calculation of the required I²t Joule integral for SiC and IGBT module protection, and selection of surge arrester class. ELTRON works with designers at every stage of product development – from concept through samples and design-in to series production – serving rolling stock manufacturers, system integrators, switchgear prefabrication plants, and photovoltaic and energy storage installation contractors.

🔗 Full range of Mersen fuses available at ELTRON »