Electrical transient overvoltage protection is a critical aspect of ensuring the safety and reliability of industrial electrical systems. Transient overvoltages, also known as voltage surges or spikes, are temporary increases in voltage levels that can occur on the power supply network. These transients can be caused by various factors, such as lightning strikes, switching operations, or faults in the power system.
The concept of electrical transient overvoltage protection involves implementing measures to mitigate the harmful effects of these voltage surges on industrial equipment and systems. Here's an overview of the key components and concepts involved:
Surge Protection Devices (SPDs): Surge protection devices, also called transient voltage surge suppressors (TVSS) or surge arrestors, are specialized devices installed in the electrical system to divert excessive transient voltages away from sensitive equipment. SPDs act as a pathway for the transient current to flow safely to the ground, protecting connected devices from damage.
Location of SPDs: SPDs are strategically placed at critical points in the electrical distribution system. Common locations include the main electrical service entrance, distribution panels, and close to sensitive equipment or electronic devices that are susceptible to voltage surges.
Lightning Protection: Lightning strikes are a significant source of transient overvoltages. Proper grounding systems, lightning rods, and surge protection measures at the building's roof level help divert lightning currents safely into the ground.
Surge Capacitance: Capacitors in electrical systems can store and release electrical energy, making them vulnerable to voltage surges. In certain cases, surge capacitors or surge capacitors banks may be used to protect such capacitive loads from overvoltages.
Earthing (Grounding): An effective grounding system is essential for diverting excess transient currents safely into the earth. Proper grounding minimizes the risk of equipment damage and ensures the safety of personnel.
Overvoltage Coordination: The protection system should be designed and coordinated such that SPDs and other protection devices work together effectively to limit the transient voltage magnitude and duration within safe limits.
Monitoring and Maintenance: Regular inspection and maintenance of the protective devices are crucial to ensure their continued effectiveness. Periodic testing and replacement of SPDs might be necessary, as they can degrade over time due to repeated surges.
The goal of electrical transient overvoltage protection is to safeguard sensitive industrial equipment, electronic devices, and electrical systems from damage or malfunction caused by voltage surges. By implementing appropriate surge protection measures, industries can minimize downtime, reduce repair and replacement costs, and ensure a safer working environment.