How are glass tubular fuses rated?

Glass tubular fuses are rated primarily by amperage, which indicates the maximum current that the fuse can allow to pass through it without blowing. This rating is crucial because it ensures that the fuse will protect the electrical circuit by interrupting the flow of current if it exceeds safe levels.

When a current exceeds the amperage rating of the fuse, the heat generated causes the fusible element inside the fuse to melt, thereby breaking the circuit and preventing potential damage to equipment or fire hazards.

While voltage is important in ensuring the fuse can operate safely within a given electrical system, the direct rating that determines when a fuse will blow is based on the amperage. Resistance and wattage are factors related to the overall function and design of electrical systems but are not used as primary ratings for glass tubular fuses. Amperage ratings specifically address the protective function of the fuse, making them the essential characteristic for its operation.