{"id":22754,"date":"2022-11-23T11:28:52","date_gmt":"2022-11-23T16:28:52","guid":{"rendered":"https:\/\/www.parsons.com\/?p=22754"},"modified":"2023-05-31T17:20:00","modified_gmt":"2023-05-31T21:20:00","slug":"the-electric-distribution-system-where-the-grid-meets-the-customer","status":"publish","type":"post","link":"https:\/\/www.parsons.com\/2022\/11\/the-electric-distribution-system-where-the-grid-meets-the-customer\/","title":{"rendered":"The Electric Distribution System \u2013 Where The Grid Meets The Customer"},"content":{"rendered":"\n
\"Energy<\/figure>\n\n\n\n

This is the fourth in my series of articles focused on the Modernization of the Electric Grid<\/a>, and it presents a discussion on the largest, yet often unappreciated, portion of the grid \u2013 the electric distribution system. The transmission system (the focus of articles two<\/a> and three<\/a>), with its huge and highly visible infrastructure components (and equally huge investment costs!) connecting large regions of the country, garners much of the attention of society. The distribution grid has much smaller components, is more spread out and diverse in construction, and can seem to just fade into the \u201cnoise\u201d of all the other municipal and utility streetside wires and equipment. For example, how many people can really tell the difference between an old telephone wire, fiberoptic line, cable TV wire, traffic signal wire, or a 25 thousand-volt (KV) primary distribution line? Yet, the distribution system is massive \u2013 multiple times larger than the transmission network – and its impact on quality of service for all customers is also much more significant. And when it comes to grid modernization, the distribution grid is where all the excitement is!<\/p>\n\n\n\n

The distribution system radiates out from the transmission-supplied substations and provides grid connection to all customers through equipment, wires, and cable located above and below ground in our cities and neighborhoods. Primary circuit voltages (distribution voltages are considered a \u201cmedium voltage\u201d class) range from around 5 KV up to 35 KV. Pole top and pad mount transformers provide a step down to the \u201clow voltage\u201d class levels used in our homes and businesses (120 V and 240 V for homes, and up to 480 V for commercial and industrial uses).<\/p>\n\n\n\n

The size of the distribution system is far larger than the transmission grid, as it extends over almost every street in any town to reach every customer premise. The diversity of equipment types and ages on the distribution system is also far greater than on transmission facilities. Many parts of the system exceed 50 years of age (I remember when I thought that was pretty old!), as typically conductors and equipment only get replaced when they either fail or are deemed no longer reliable. Distribution facilities also get upgraded or replaced when they happen to be in the way of road and highway upgrades, or when circuit capacity needs to be increased for new customers or increased load.<\/p>\n\n\n\n

Some other factors that set the distribution system apart from the parent transmission grid are:<\/p>\n\n\n\n