What is an internal fuse described as?

An internal fuse refers specifically to a type of fuse that is located within the equipment or component it protects, as described in the correct answer. It serves a critical role in protecting the internal circuits of devices, such as transformers, by interrupting the flow of electricity if a fault occurs, thereby preventing damage to the equipment.

In this case, the internal fuse is positioned inside the H1 bushing of a transformer, which is a common setup in electrical systems. This placement helps ensure that any faults are managed internally, providing a more streamlined and efficient protection mechanism compared to external options.

The concept of an internal fuse being the same as a cutout fuse but located inside highlights the distinction between different types of fuses and their protective functions within electrical systems. Understanding this configuration is crucial for comprehending transformer protection and the overall safety mechanisms in high-voltage circuits.