What is a key reason for ensuring one finger of the bridging reactor always makes contact?

Ensuring that one finger of the bridging reactor always makes contact is crucial primarily because it guarantees a continuous power supply during tap changes. In the context of tap-changing transformers, maintaining contact during adjustments is essential to prevent interruptions in the power supply. If contact is lost, it can lead to voltage fluctuations and possible outages, affecting the reliability of the electrical system.

In operational scenarios, when a tap change is made, it's vital that there is a seamless transition without disrupting the flow of electricity. This continuous connection allows the system to adjust to load changes without affecting the overall stability or availability of power. Therefore, the consistent contact of one finger of the bridging reactor serves a critical role in ensuring that the energy supply remains uninterrupted during these necessary adjustments.