ABSTRACT
This chapter discusses the two components of conductor impedance, resistance and reactance. The impedance of electrical conductors has a significant effect on the design of most electrical equipment. The conductors in such apparatus include bus bars, cables, terminals, contacts, pigtails, resistant wires, and coils. In turn, physical size is usually determined by the permissible temperature rise or heat capacity, mechanical function, and electrical impedance requirements. In low-impedance bus duct systems, the voltage-drop variations in each phase are usually ignored. In such cases the variations in individual conductor impedance become negligible. Alternating currents induce an electromotive force in the conductor which opposes the electromotive force associated with current flow. Additional increases in ac resistance occur if conductors are enclosed in a high-permeability housing material such as steel. The chapter looks at the influence of a steel housing on bus conductor impedance.
