Schneider Electrics Square D™ transformer disconnects mount inside or outside a control system enclosure and provide power to auxiliary, 1-phase loads when the main three-phase disconnect is either ON or OFF. The transformer disconnect is normally wired to the line side of the control panel's main disconnect. This convenient source of 120 V power can be used for auxiliary or isolated loads, such as panel lighting, portable power tools and programmable controller equipment. Units consist of copper wound transformers, a disconnect switch and primary and secondary fuse blocks. All blocks are installed in NEMA 1 or NEMA 12 enclosures.