KBR noted "several safety issues concerning the improper grounding of electrical devices". The size of power grounding conductors is usually regulated by local or national wiring regulations. "Mesh voltage" is a factor calculated when a grid of grounding conductors is installed. A grounding (earthing) system must be designed. The ground pin is round, like those on straight-blade NEMA grounding devices. Prior to positioning, grounding and lightning protection are required. Isolation is a mechanism that defeats grounding. Such cable combines the functions of grounding and communications. The Chargers' fans saw the fumble as an incomplete pass or an intentional grounding. Much work in acoustics requires a good grounding in Mathematics and science. Even fiction usually has elements of or grounding in, truth. Each EPP has two 100-gallon fuel tanks and a fuel distribution assembly with grounding equipment. Some terminators have a metallic chain attached to them for grounding purposes. The twin propellers and rudders had protection from grounding. Form S.232 being the formal notification of a grounding or collision.