The 'loadcenter' unit substation concept and World War II

In this "Cut the Copper" installment, we learn about how the shortage of copper forced plant electrical engineers and consulting engineers to become more creative in their designs of electrical power systems for large industrial plants.


During World War II and immediately afterward, U.S. manufacturing industries were running at hyper-speed, expanding as fast as possible to keep up with wartime and post-war demand for products of all types.

Throughout the war, supplies of copper were exceedingly tight. Virtually all of the copper that could be produced and obtained by the U.S. went into the war effort. Demand for things like internal wiring for all of the new ships and planes and tanks, cable and bus for the new plants being built to manufacture the war machinery, and munitions and copper shell casings, all combined to consume virtually all of the copper that was available.

The supply of copper became so tight that for several years the U.S. Mint even coined pennies punched out of steel (zinc plated, to prevent rusting) in order to conserve precious copper for uses strategically more important than pennies.

The overall situation forced plant electrical engineers and consulting engineers to become more creative in their designs of electrical power systems for large industrial plants, and the “Loadcenter Unit Substation” concept was born.

Comparison of copper used with 'loadcenter' approach versus outdoor tranformer and 450 V duct bank.The basic concept was that if you could take medium voltage distribution at 5, 15, or 25 kV, and run it long distances deep inside a big factory over very small conductors, then connect it to step-down transformers located “in the center” of the actual heavy loads, then the very large cross-section low voltage secondary feeder cables could be greatly reduced in length.

So, Askarel-filled “loadcenter unit substations” became instantly popular, and were installed right out in the middle of manufacturing floors or on mezzanines directly above them, in thousands of plants all over the country. Where intelligently designed, the concept could often eliminate the need for about 80% of the copper that otherwise would have been required, so this was great innovation with important consequences. The terms “Loadcenter Unit Substation” and just plain “Loadcenter” stuck in the industry for decades.

This trend continued during the huge industrial expansion immediately after the war. And, over the next 30 years, tens of thousands of Askarel-filled loadcenter substation transformers were produced and installed inside industrial buildings.

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