Industrial Substations

What exactly is a substation, and how the electrical industry is working toward a more specific definition.

The term “substation” is used loosely throughout industrial facilities. The term is actually defined in Part I of Art. 100 of the 2014 Edition of the National Electrical Code (NEC).  However, the definition leaves a lot to be desired for Code users.

As defined, the term could fit many enclosed pieces of equipment since it isn’t very specific.  The High Voltage Task Group, appointed by the Technical Correlating Committee, is now working to redefine and clarify what a substation is via the Public Input (PI) process, formally known as Code Proposals. Hopefully, by the time the PI makes its way through the rigorous Code process, we will have a better definition to work with.

Many industrial users apply the term to any installation where there are transformers, switchgear, motor control centers, or a combination thereof, regardless of voltage level. But as noted in Part I of Art. 100, it clearly designates that it applies to equipment operating at over 600V. Based on work currently being done by the High Voltage Task Group, it’s anticipated the new definition will be moved from Part I to Part II of this Article and apply to equipment operating at over 600V.

Regardless of how the new definition reads or where it ends up in the 2017 NEC, I feel there is still much work to be done in future Code cycles regarding substations. For the first 100 years the NEC was primarily a residential and commercial Code with industrial facilities being left to establish safe practices and installations on their own. Unfortunately, this is still the case in many situations. As the Code becomes more mature over time, I’m sure we will continue to see it apply more and more to industrial facilities.

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