How should Type S fuse adapters be designed in relation to their fuse holders?

Type S fuse adapters are designed to enhance safety and prevent misuse in electrical systems. The key feature of these adapters is that they must remain permanently locked in place within their fuse holders. This locking mechanism prevents the use of incorrect fuse types or sizes, which could lead to inadequate protection of the circuit or possible electrical hazards.

By ensuring that Type S fuse adapters are secured, they mitigate risks associated with unauthorized or accidental replacement of fuses with incompatible types, maintaining the electrical system's integrity. This permanency is essential for compliance with safety standards and regulations, ensuring that only the correct, rated fuses are used within the electrical circuits.

The other options suggest features that do not align with the primary objective of Type S fuse adapters. Options suggesting that adapters should be easily removable or adjustable would compromise safety, while a color-coded indicator might be helpful in some applications but does not address the critical function of securing the adapter in place.