aR fuses
Back-up ultra-rapid fuses for fast short-circuit protection, with reduced I²t values. Suitable when the main protection is coordinated with other switching or protection devices.
Ultra-rapid aR, gR and gS fuses for the protection of diodes, thyristors, IGBTs, converters, rectifiers, variable speed drives, UPS systems, inverters, batteries and industrial power electronics equipment.
TOT POWER Iberia specialises in semiconductor protection fuses and works closely with manufacturers such as DF Electric and SIBA. We can also locate equivalent or alternative references from other manufacturers, such as Eaton or Mersen, depending on the customer’s technical and commercial requirements.
Supply, equivalence search and technical-commercial support for ultra-rapid fuses used in power electronics.
Power semiconductors operate under high current, voltage and thermal stress. In the event of a short circuit, let-through energy must be limited very quickly to prevent damage to diodes, thyristors, IGBTs, power modules and associated electronics.
Ultra-rapid fuses are designed to operate with low I²t values, high breaking capacity and suitable behaviour under cyclic loads. Correct selection depends on rated current, operating voltage, semiconductor type, operating class, thermal dissipation, mounting conditions and coordination with the rest of the equipment protection system.
TOT POWER Iberia can supply cylindrical fuses, NH fuses, square body fuses, busbar-mounted versions and specific solutions for power applications, industrial maintenance and replacement of existing equipment.
Back-up ultra-rapid fuses for fast short-circuit protection, with reduced I²t values. Suitable when the main protection is coordinated with other switching or protection devices.
Full-range semiconductor protection, covering both overloads and short circuits. Suitable when the aim is to protect the semiconductor device and part of the associated installation.
Comprehensive protection solutions for applications where cables, busbars and switchgear must also be protected, especially in modern power and energy systems.
NH formats for high-current applications, used in rectifiers, converters, drives, power supplies, energy storage systems and industrial switchboards.
Square body fuses and busbar-mounted versions for high current, low connection inductance and semiconductor protection in industrial power equipment.
Fuse selection for alternating current and direct current circuits, considering rated voltage, breaking capacity, L/R constant, dissipation and real mounting conditions.
We work with manufacturers specialising in electrical protection and ultra-rapid semiconductor fuses. Our aim is not only to supply a reference, but also to help the customer find the technically suitable solution when there is an original reference, a drawing, a physical sample or a replacement requirement.
Range of ultra-rapid fuses for semiconductor protection, including cylindrical, NH and square body formats, designed for industrial power electronics applications.
Ultra-rapid fuses for the protection of power semiconductors in converters, UPS systems, drives, renewable energy, battery systems and other industrial applications.
When the customer has an existing reference, we can study compatible alternatives from other manufacturers, checking operating class, dimensions, current, voltage and I²t.
These fuses are used wherever disconnection must be fast and let-through energy must remain within limits compatible with semiconductor protection.
Protection of input rectifiers, DC links, power stages and AC/DC motor control equipment.
Applications using diodes, thyristors and power modules where protection coordination is critical.
Protection in energy storage systems, industrial chargers, battery banks and DC systems.
Fuses for inverters, strings, DC protection and conversion equipment in renewable energy installations.
Semiconductor protection in welding power supplies, rectifiers and high-current converters.
Replacement of old, obsolete or hard-to-find references in machinery and existing switchboards.
Semiconductor fuse equivalence should not be based only on rated current. Voltage, breaking capacity, operating class, pre-arcing and total I²t, thermal dissipation, time-current curves, current limitation, mounting and environmental conditions must also be reviewed.
TOT POWER Iberia helps review the available information and propose a suitable reference when there is sufficient technical basis for comparison.
| Criterion | What to check |
|---|---|
| Class | aR, gR, gS or any other class specified by the equipment manufacturer. |
| Voltage | AC/DC voltage, breaking capacity and circuit conditions. |
| Current | Rated current, load cycles, ambient temperature and derating. |
| I²t | Pre-arcing and total energy compared against the semiconductor withstand capability. |
| Mounting | Cylindrical, NH, square body, busbar, striker, microswitch or compatible fuse holder. |
In addition to ultra-rapid semiconductor fuses, we can support customers with related protection devices in the same power environment: batteries, inverters, photovoltaic systems, DC switchboards and energy conversion systems.
If you have a reference from DF Electric, SIBA, Eaton, Mersen or another manufacturer, we can study an available and technically compatible alternative. This service is especially useful for maintenance, industrial equipment repair, plant shutdowns, urgent replacement or when the original reference has a long lead time or is obsolete.
The more technical information TOT POWER Iberia receives, the faster a suitable alternative can be verified.
Brand, model, complete code, fuse photo and, if available, the original datasheet.
Rated current, AC/DC voltage, aR/gR/gS class, breaking capacity, I²t and circuit type.
Dimensions, connection type, blade, thread, busbar mounting, striker, fuse holder or microswitch.
Equipment where the fuse operates: drive, rectifier, UPS, inverter, battery, welding system, furnace, converter or DC panel.
An aR fuse is mainly intended for short-circuit protection and usually works in coordination with other protective devices. A gR fuse provides full-range semiconductor protection, covering both overloads and short circuits.
Yes, but the comparison should not be based only on rated current and size. Voltage, class, breaking capacity, I²t, dissipation, curves, dimensions, connection system and the real application must be checked.
Yes. TOT POWER Iberia works with manufacturers such as DF Electric and SIBA to supply ultra-rapid semiconductor fuses and support customers in reference selection or equivalence studies.
Yes. When the customer has a specific reference, we can review alternatives from Eaton, Mersen or other manufacturers, provided that a technically verifiable equivalence exists.
Complete reference, fuse photo, required quantity, voltage, current, service class, dimensions, application and required lead time. If there is a datasheet or equipment drawing, it should also be attached.
Send us the reference you need, a photo of the fuse or the equipment datasheet. We will review the best available option and reply with a technical and commercial proposal.
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