What is the primary cause of low power factor in overhead systems?

The primary cause of low power factor in overhead systems is indeed the inductive loads on those systems. Inductive loads, such as motors, transformers, and coils, require reactive power for their operation, which does not contribute to the actual power (real power) consumed by the load but is necessary for maintaining the magnetic fields within these devices. When these inductive loads dominate in a system, the overall power factor decreases, leading to inefficiencies in the electrical power system.

A low power factor results in a larger amount of apparent power being required to provide the same amount of real power, which can lead to increased losses in the distribution system and strained resources in terms of generation and transmission. This is why utilities monitor and sometimes charge penalties for low power factor levels, as it can impact the capacity and efficiency of the electrical grid.

In contrast, capacitively loaded systems can help improve the power factor by offsetting inductive effects, while high voltage drops across transformers and excessive resistive heating pertain to issues related to energy losses rather than the underlying cause of low power factor in the context of inductive loads.