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DOE’s New Rule: PSC Motors Are Out, CTM Motor Are In

May 15, 2019In 1883, Nicola Tesla invented the first induction motor with rotating magnetic fields thus starting a second industrial revolution still evident today.

The global market for electric motors is close to 100 billion U.S. dollars and is expected to grow to 141 billion by 2022 according to Sherry James of Grand View Research. Now, 136-years later, unless there is some divine intervention, the Permanent Split Capacitor (PSC) motor that is barely able to convert a paltry 65% of its electrical input into mechanical work is on its way out. PSC motors suffer from asynchronous alignment, meaning the rotor constantly lags the magnetic field in the stator. This is known as slippage. A six pole PSC motor, for example, should turn at 1200 RPM but because of slippage it turns at 1075 rpm. This considerable amount of waste heat is the byproduct of slippage. The Department of Energy (DOE) published a final rule regarding residential furnace fan energy ratings (FER) in July of 2014 mandating major manufacturers with sales over $8 million be required to have FER-complaint furnaces in production by July 3, 2019.