Electrical power is a critical service that profoundly affects our daily lives. Without it, we would lose cellphone service, safety on city streets would be compromised because lights would not work, and the quality of life as we know it would diminish significantly. We would have to close schools and hospitals, and most jobs would be eliminated. Much of our food supply also would be critically impacted.
To continue living the life we are accustomed to – and have come to expect – we must have a reliable source of electricity, which starts with generation. Outside the generation station, power typically is stepped up to a higher voltage and usually ends up at a transmission system voltage (i.e., 115 to 550 kV). Transmission substations provide a means to transmit and protect the high-voltage transmission systems throughout the U.S. To distribute the power to homes and businesses, the transmission voltage is stepped down to lower voltages in distribution substations. Both transmission and distribution substations have breakers and fuses to provide system protection, along with many other parts and pieces that provide protection for equipment, personnel and the public, as well as reliability.
To ensure that power is always available, utilities must be diligent – engaging in regular inspections and National Electrical Safety Code (NESC) audits – in identifying conditions that may impact reliability and safety. The NESC has been around for approximately 100 years. Initially created as a guide to help electrical professionals understand safe design and work practices for generation, transmission and distribution systems, it is a culmination of many other standards, some of which will be referenced in this writing. Substations – or “supply stations,” as they are referred to in the NESC – are an integral part of our transmission and distribution infrastructure and have inherent hazards that must be considered.