The invention disclosed herein relates to a motor arrangement with an electronically commutated electric motor of an explosion-protected configuration. The arrangement includes a permanent magnet rotor and stator separated by an air gap. At least one galvonmagnetic rotor position sensor is provided for detecting a magnetic field of the permanent magnetic rotor whose output signal serves for controlling an electronic commutation device. The current supply of the galvanomagnetic rotor position sensor is realized by an alternating current or three- phase current supply system with interconnection of an isolation transformer. The output signal of the galvanomagnetic sensor is supplied via an optocoupler to the electronic commutation device. The actual electronic commutation device of the motor arrangement is preferably arranged external to the electric motor. The arrangement provides a motor that is suitable for operation in a potential explosive environment and is less expensive than conventional arrangements.
