Rely on the standards of tomorrow today
Automation and electrification are raising safety and reliability standards for electrical systems. What new surge protection standards and norms are required, and how can they be implemented? This article explores these questions.
The All Electric Society vision involves comprehensive electrification, networking, and automation across all sectors. This increases safety demands during electrical system installation and operation. Surge protection is crucial for preventing transient overvoltages, not only in industrial applications and building technology but also in renewable energy, DC systems, production facilities, data centers, battery storage, and e-mobility charging infrastructure. New concepts for lightning and surge protection are often required.
Special attention must be given to the safety and reliability of surge protective devices, as reflected in the latest updates to the EN/IEC 61643 series standards and norms.
Method of operation of surge protective devices
Surge protection encompasses lightning protection (type 1), conventional surge protection (type 2), and device protection (type 3). Notably, type 2 surge protection has long been utilized in main and subdistribution systems in buildings and industrial control cabinets. These devices limit surge voltage to a specified maximum (voltage protection level) and prevent surge currents from discharging across protected devices.
Furthermore, they undergo normative tests with multiple surge currents to ensure functionality throughout their service life. Additionally, internal and external protective devices guard against overloads and faults, such as ground faults or neutral conductor loss, which can cause premature aging.
What does the upcoming EN/IEC 61643 series mean for surge protection?
Standards for surge protective devices (SPDs) are being revised at IEC and CLC levels to accommodate new applications driven by power supply decentralization, renewable energy conversion, and diverse energy sources. Consequently, IEC 61643-01 will become the basic product standard for SPDs in low-voltage systems, defining safety and performance requirements, including protection against electric shock, voltage protection level, discharge capacity, and behavior under aging, overload, and short-circuit conditions. Additionally, it covers air clearances, creepage distances, mechanical strength, and terminal point testing.
Moreover, specific requirements for different applications include overload tests and behavior under temporary surge voltages. Importantly, the focus is on safety, including overload and short-circuit behavior, and requiring double or reinforced insulation for remote signaling and auxiliary circuits connected to extra-low voltage (ELV) systems like SELV and PELV.
Valvetrab SPP: Clear focus on simplicity and safety in installation and operation
Phoenix Contact’s Valvetrab SPP (Safe Protection Plus) meets new requirements with a focus on simplicity and safety in installation and operation. Specifically, it features reduced tightening torque (3 Nm) and usage up to 315 A without backup fuses. Additionally, miswiring protection prevents incorrect connections and accidental contact with live components, reducing the risk of electric shock. Other safety features include high-performance disconnection, double insulation, and increased air clearances and creepage distances.
High-performance disconnection
Fast, internal disconnection ensures safe failure of an overloaded surge protective device at the end of its life, enabling safe use and maximum system availability. In the Valvetrab SPP range, this is achieved through a direct thermal connection of a disconnect device to the metal oxide varistor (MOV). The Arc Shield provides active mechanical protection against electric arcing.
Double or reinforced insulation between the main circuit and remote signaling
After an overloaded surge protective device fails safely, it must be replaced to ensure protection against transient overvoltages. Consequently, an electrical remote signal, along with an optical display, can indicate this need. Furthermore, if the remote signaling is supplied by an auxiliary circuit, proper insulation between main and auxiliary circuits is crucial for safety. Importantly, the Valvetrab SPP range already includes the required double or reinforced insulation for SELV and PELV systems.
New potential applications with extended air clearances and creepage distances
Choosing the right surge protective device depends on the supply system configuration and installation location requirements. Consequently, Valvetrab SPP meets normative requirements for air clearances and creepage distances, allowing use at altitudes up to 5,000 m and in harsh, dirt-prone environments with surge protection category 3 (OVC III), pollution degree 3, and 400 V nominal voltage, which are common in industry.
Learn more about the new Valvetrab Safe Protection Plus (VAL-SPP) surge protective devices.
