A rating plate on a machine carries information about its operational limits. The plate frequently contains the names of the machine and its manufacturer, so the rating plate is often called a name plate (hence the term "nameplate capacity" for a generator), although many devices carry separate nameplates and rating plates.

For an electric machine, the power rating is the number on its rating plate and corresponds to a maximum electric load it can carry. There is a distinction between the continuous rating (for generators, continuous maximum rating or CMR), at which the machine can be operational without a time limit and short-term rating that can only be used for a specified amount of time.

A typical electrical generator rating plate contains the following parameters: