🔍 Key Concepts

• Effect of voltage on current draw and heating in induction motors • Effect of frequency on motor speed, magnetic flux, and core saturation • Nameplate ratings: how rated voltage and frequency are intended to be used together

💭 Think About

• If you reduce the voltage to an induction motor but keep the same mechanical load, what happens to the current and copper losses? • If you reduce the frequency while keeping the same applied voltage, what happens to the magnetic flux in the iron and the iron losses? • How are rated voltage and rated frequency related on a motor nameplate (think about the V/Hz ratio)?

✅ Before You Answer

• Check which condition(s) would increase current at the same load and therefore increase I²R (copper) losses • Check which condition(s) would increase magnetic flux in the core and therefore increase iron/core losses and heating • Verify whether each condition (I and II) on its own would reasonably lead to excessive temperature rise in a three-phase squirrel-cage induction motor