A system for installing wiring and cable in new and existing buildings has a tray member which will be coupled to a bottom section of a wall and run a length of the wall. The apparatus includes a microcontroller that senses a reference voltage, and a sensed voltage signal that comprises a voltage component representing a relay coil voltage, a power supply voltage component, and a voltage component induced by a motion of the armature. A FEM grid model is created to represent the structures using a plurality of solid elements which represents geometry and material properties.