Electrical

Abstract

Electricity is a form of energy, and is useful when it is controlled and transmitted; it changes a project from a static structure to a functioning facility. The voltage is lowered at the consumer’s end of the system, where voltages are usually between 13 kV and 4.16 kV. The subfeeders may be three-phase or single-phase, where the single-phase voltage is the three-phase voltage divided by 1.73. The consumer’s substation may contain one or more voltage step-down power transformers, and may be part of the facility or owned by the supplying utility. The standard nominal voltage levels at the substation could be 115, 230, 227, 480, or 550 V. Within the facility the equipment includes metering feeder cables, busways and conduit, switchgear, panel-boards, circuit breakers, motor control centers, device wiring connections, and all similar equipment for control and safety. (See Fig. C-16-1.)