In this blog, we're going to delve into the four phases of an electric arc in a panel, detailing each stage of this both dangerous and fascinating phenomenon. An electric arc is a discharge of intense, luminous energy between two conductors, commonly seen as a bright flash of light. This process involves four main stages: compression, expansion, expulsion and thermal, and understanding these phases is crucial to enhancing safety in electrical installations.

 1. Compression Phase

The compression phase occurs when electrical energy builds up rapidly between two contact points that have lost their ideal connection, as can happen with loose or damaged connections. This build-up results in high pressure and an increase in temperature, initiating the ionization of the surrounding air and the formation of the arc.

2. Expansion Phase

In the expansion phase, the ionized air expands vigorously due to the extreme heat generated by the electric arc. The accumulated energy is released explosively, increasing the volume and pressure of the air, which can cause significant damage to electrical equipment and the panel.

3. Expulsion Phase

During the expulsion phase, ionized and conductive particles are literally expelled from the arc site, often accompanied by sparks and hot debris. This phase is particularly dangerous as it can result in fire or serious injury if personnel are nearby.

4. Thermal Phase

Finally, in the thermal phase, the heat from the electric arc reaches its peak, with temperatures that can exceed 10,000°C. This intense release of heat affects not only the components directly involved in the arc, but also adjacent areas, and can melt materials and degrade insulation.

Understanding these phases is essential for implementing appropriate protective measures. With this in mind, Varixx has developed Zyggot Arco system, which uses advanced technology to detect the formation of electric arcs. Detection is based on the ultraviolet radiation emitted during the ionization of the air, still in the pre-arc phase, enabling an ultra-fast response. The system is capable of sending a shutdown signal in up to 300 microseconds, thus guaranteeing the lowest incident energy on the market and significantly increasing safety in electrical installations.

We hope that this in-depth look at the phases of the electric arc will help you to better understand this phenomenon and the importance of effective protection to ensure the safety of everyone involved.