Monitoring relays help to protect some of the most expensive and sensitive equipment in industry. They are also used to provide protection for the components in some appliances. These devices prevent machinery and electronics that are sensitive to fluctuations in the power grid by reacting to specific types of changes. Relay technology itself is not new. Relay switches have been in use for over 100 years and are basic components of electrical systems and basic tools of electrical design and engineering.
Relay switches have become much more advanced over the decades, however. This allows them to be set to very specific tolerances and, therefore, to provide excellent protection for the devices that they are used to monitor.