IR?TEC's PPU series power pack not only provides 24 VDC power supply for the operation of IR?TEC low voltage sensors, but also accepts control signals from connected sensors to control the lighting circuits, motors, self-contained air?conditioners, VAV systems, fans and motorized damper controllers. The PPU series can be attached to a junction box through a 1/2" knockout with the designed threaded nipple and locknut.