Nonresettable

Nonresettable is an adjective describing components, systems, or data that cannot be reset to an initial or default state after a triggering event. When a device is nonresettable, recovery to its original state requires replacement or physical intervention rather than software or user action.

In hardware, nonresettable devices are often used for fail-safe protection or auditing. A classic example is a nonresettable fuse, or one-time fuse, which permanently interrupts current when a fault occurs. After it blows, the circuit cannot be reset; the fuse must be replaced. This is in contrast to resettable fuses (PTCs) that restore conductivity after the fault is removed. Nonresettable protection is common in power supplies, automotive safety systems, and certain consumer electronics where a persistent fault or tamper-evident condition must be clearly indicated.

In metering and safety equipment, nonresettable elements include tamper-evident seals and nonresettable trip counters in breakers or safety interlocks. These features provide auditable evidence of faults or unauthorized access, since their state cannot be undone by a user.

In computing and data storage, nonresettable can describe memory or counters that cannot be erased or restored to zero. One-time programmable (OTP) memory is a typical example, where each memory cell is written once and cannot be reprogrammed. Nonresettable counters or logs may be used to ensure integrity in auditing, compliance, or cryptographic protocols.

Overall, nonresettable denotes a design choice prioritizing permanence of a fault indication, data integrity, or tamper-evidence over the ability to recover with a simple reset. Examples span electrical protection, metering, and certain forms of digital storage.