What is the purpose of running all three phases together in the same conduit?

The purpose of running all three phases together in the same conduit primarily revolves around the concept of reducing inductive reactance. When three-phase conductors are placed closely together, they experience mutual coupling, which can lead to a reduction in overall inductive reactance for the circuit. This configuration helps ensure that the magnetic fields generated by each phase interact in a way that minimizes their individual inductive effects.

By reducing inductive reactance, the system becomes more efficient as it lowers the voltage drop across the conductors and improves the overall power factor of the electrical system. Additionally, this alignment helps balance the load more effectively across the three phases, leading to a more stable and reliable power supply.

While the other options might seem relevant in different contexts (such as maintenance efficiency or noise reduction), they do not directly address the electrical properties and benefits associated with how inductive reactance is managed when three phases are grouped together.