“Outside” or “line” contractors are responsible for high-voltage power transmission and distribution lines. Line contractors see that electricity generated at power plants is safely carried through high-voltage lines and substations before it’s used to power any facilities, buildings, or homes.
“Inside” electrical contractors provide electricity to buildings and structures. Inside electrical contractors can serve as prime contractors for all electrical and cabling design, installation, and maintenances in commercial, institutional, and residential buildings.
“Integrated building systems” (IBS) or “Voice/Data/Video” (VDV) electrical contractors work primarily with low-voltage installations, including back-up power, climate controls, wireless networks, energy-efficient lighting, telecommunications, fiber optics, and security systems. IBS contractors integrate these system controls for maximum energy efficiency and building performance.