Klamppausjännite

Klamppausjännite, also known as clamping voltage, refers to the maximum voltage that a surge protective device (SPD) will allow to pass through to a protected circuit. When a transient overvoltage, such as that caused by lightning or switching operations, occurs, an SPD activates. This activation causes the SPD to divert the excess energy away from the protected equipment. The clamping voltage is the voltage level at which this diversion begins and effectively limits the voltage that reaches the sensitive electronics.

Different types of SPDs have varying clamping voltages. For example, Metal Oxide Varistors (MOVs) are commonly used and their clamping voltage is determined by the specific MOV used. The lower the clamping voltage, the better the protection offered to the equipment. However, a lower clamping voltage might also lead to more frequent activation of the SPD, potentially shortening its lifespan or causing nuisance tripping in some cases if not properly selected for the application.

The selection of an appropriate clamping voltage is crucial for effective surge protection. It must be low enough to protect the connected equipment from damage, but not so low that it causes unnecessary stress on the SPD itself. Standards and guidelines often specify maximum permissible clamping voltages for different types of equipment and electrical installations to ensure adequate safety and reliability. Understanding the clamping voltage of an SPD is therefore essential for designing and implementing effective overvoltage protection strategies.