The invention relates to a bleed air supply system and a safety device for closing a valve in at least one of the several bleed air supply lines depending on an alarm signal that indicates an opening in at least one of the several bleed air supply lines. The construction system comprises a plurality of lifting rams operatively coupled to a power source and a controller operatively coupled to the power source to control the lifting rams. A microcompressor supported by the substrate compresses a cooling fluid. The input terminal configured to provide an input common mode voltage and the output terminal configured to provide an output common mode voltage.