Calculation of device power in case of group drives

Question:
How is the required device power of group drives (several motors mounted to one drive controller) calculated?

Answer:
The sum of the motor rated current must be ≤ device rated current.

Example 1:  3 x motor 0.25 kW, U = 230 V, I = 1.32 A
          sum of the motor currents = 3 x 1.32 A = 3.96 A
      selected: Device power 0.75 kW with 4.0 A rated current (230 V)

Example 2:  6 x motor 0.25 kW, U = 230 V, I = 1.32 A
      sum of the motor currents = 6 x 1.32 A = 7.92 A
      selected:  Device power 2.2 kW with 9.5 A rated current (230 V)

Note regarding example 2:  
The sum of the motor powers (6 x 0.25 kW = 1.5 kW) would have led to a device with too low rated current (1.5 kW device = 7.0 A).

URL for linking this AKB article: https://www.lenze.com/en-de/go/akb/200410981/1/