The WVR-PDT Series sensors are a cost effective answer to retrofitting classrooms with obstructions and inaccessible ceilings. Additionally, these self contained line voltage sensors do not require neutral, meaning the sensor can wire directly off local switches! Typical retrofits utilize wire mold coming out of a local switch up to the sensors mounting location. In new construction, an electrical junction box can be located in the wall with the sensor wired to interrupt the feeds to the switches. The WVR-PDT Series sensors use Passive Dual Technology which combines Passive Infrared (PIR) and Microphonics detection technologies. For two pole applications, the see the WVR-PDT-2P Series.