摘要 |
The device (1) has an electric motor (2) to drive a fan wheel (6) connected to the electric motor. The electric motor is controlled by a control unit (18). A casing (3) is arranged to accommodate the electric motor. Another casing (13) is arranged to accommodate the control unit. The other casing is mounted in the former casing such that the later casing exceeds the former casing in an assembling state. |