Fast transients in power systems can damage cables, motors, transformers, instrument transformers, reactors, and other equipment in both distribution and transmission networks. They are generated not only by lightning, but also by system switching operations or even by power electronics. As discovered more recently, the interaction between devices with specific highfrequency characteristics can lead to abnormal and harmful surges with steep fronts and high frequency components. Often, the existing means of surge protection, like surge capacitors, ZnO arresters, and even RC snubbers are not sufficient or are too cumbersome to be installed effectively against these surges. SmartChoke is a new type of device that can provide a better way of protecting the system. This paper presents some experimental verifications of the effectiveness of the device. Subsequent publications will also describe the device technology and more detailed application examples in the distribution networks.