A site power distribution board is usually an electrical distribution box equipped with various sockets to provide power for different equipment and machinery. An employee using the receptacle can plug in the portable GFCI while using equipm nt, then unplug it and take it with when finished. Portable GFCIs are of three general types—the plugin type, which provides one or two protected receptacles, the. A reliable construction site power connection is the foundation for safe workflows, predictable schedules, and the efficient use of electrically powered equipment. The IEC-60309 system consists of plugs, sockets, and. Equipped or empty socket combinations and fuse box solutions for factories, construction sites, workshops and working environments.