It shows shaft power. The kW on the nameplate is the mechanical power the motor can deliver continuously at its shaft under rated load; catalogue tables list it as P2. The electrical power drawn from the supply (P1) is larger, because winding, core and friction losses must also be covered.

The relation is P1 = P2 / η. Example: the catalogue efficiency of a 7.5 kW 4-pole IE3 motor is 90.4%. At full load it draws 7.5 / 0.904 ≈ 8.3 kW; the difference of about 0.8 kW turns into heat.

Practical consequences of this distinction:

  • The machine's requirement is compared with shaft power; generator, transformer and cable sizing use the input power and current.
  • If the motor is loaded below its rating, the power it draws also falls; the nameplate value is not what the motor draws at every moment.
  • Older nameplates may give power in HP; 1 HP is about 0.746 kW, and the catalogue lists 7.5 kW as 10 HP.

For current values by model, see the electric motor current table.