Parallelwire

Parallelwire is a configuration in electrical engineering where two or more conductors run side by side to carry electrical current or signals. By distributing the load across multiple conductors, parallelwire can increase total current capacity, reduce effective resistance, and improve mechanical robustness compared with a single conductor of equivalent cross-section.

In direct-current systems, current sharing tends to follow the conductors' resistances, so each wire carries a proportionate share if lengths and temperatures are equal. In alternating-current systems, impedance from inductance, capacitance, and mutual coupling governs current distribution, and factors such as conductor spacing, frequency, and skin and proximity effects can favor some wires over others. Designers often ensure matched lengths and controlled spacing, and may use symmetric layouts or shielding to manage impedance and minimize crosstalk.

Parallelwire arrangements are widely used in power distribution and transmission, including bus bars, parallel-running feeder cables, and multi-conductor conductors inside conduits or cable trays. They are also used in radio-frequency and laboratory settings where coupled conductors support transmission lines or flexible high-current connections. In some legacy communication systems, parallel wire pairs were used for low-frequency signaling.

Common construction involves copper or aluminum conductors, which may be solid or stranded, with insulation and protective jackets tailored to voltage and environment. The geometry—number of wires, spacing, and conductor size—controls overall impedance, capacitance, and potential for circulating currents. Paralleling introduces risks such as uneven current sharing due to temperature or aging, crosstalk, and corona effects at high voltage, which are mitigated through careful design and testing.