Differences between fan rating plates and motor plates

Questions frequently asked by customers and design engineers concern the fact that our fans sometimes have two types of plates with different data.
One plate is located on the motor housing; it is provided by the fan manufacturer and applies to fan nominal parameters, respecting electric parameters related to the usable parts of the speed-torque (or power) characteristics of the fan (depending on its type, i.e. the speed-torque characteristic of axial, radial, diagonal fans).