The nominal rating of electrical switches relates to which rating?

The nominal rating of electrical switches primarily relates to the current rating with the contacts closed. This rating indicates the maximum amount of current the switch can safely carry when it is in the “on” position, meaning the contacts are closed and conductive. This ensures that the switch does not overheat or suffer damage during operation, which is critical for safe and efficient functioning in an aircraft's electrical system.

Understanding this current rating is essential for selecting switches that will be used in specific applications within an aircraft, as using a switch that is undersized for the amount of current it will carry can lead to failure and potential hazards. Therefore, the nominal rating gives engineers and technicians clear guidance on the appropriate usage and limitations of the switch in electrical circuits.