Ülepingekaitsevahendi

Ülepingekaitsevahendi, known in English as a surge protector or surge suppressor, is an electrical device designed to protect electrical equipment from voltage spikes or surges. These surges can occur due to various reasons, including lightning strikes, power outages, or internal switching operations within the power grid. A surge protector works by diverting excess voltage away from sensitive electronic devices.

The core component of most surge protectors is a metal oxide varistor (MOV). MOVs are semiconductor devices whose resistance changes dramatically with voltage. Under normal operating voltages, the MOV has very high resistance, allowing electricity to flow to the connected device unimpeded. However, when a voltage surge occurs, the MOV's resistance rapidly drops, creating a low-resistance path for the excess electricity to flow to the ground wire, thereby protecting the connected equipment.

Surge protectors are rated based on their joule rating, which indicates how much energy they can absorb before failing. A higher joule rating generally means better protection and a longer lifespan for the device. They also have a clamping voltage rating, which is the voltage at which the MOV begins to divert power. Lower clamping voltages offer better protection. It is important to note that surge protectors are not designed to protect against sustained overvoltage conditions, which require different types of protective devices. Surge protectors are commonly found in power strips, as standalone units, and integrated into various electronic devices.