Final answer:
Cartridge fuses and fuseholders are primarily classified by voltage rating, amperage rating, and size, which are all critical for ensuring circuit safety and proper fit.
Step-by-step explanation:
Cartridge fuses and fuseholders are classified according to several characteristics, but the primary classifications are voltage rating, amperage rating, and size. These ratings are crucial for ensuring that the fuse can safely and effectively interrupt the circuit if the current exceeds safe levels. The amperage rating, also known simply as the amp rating, is directly related to the purpose of the fuse, which is to prevent too much current from passing through an electrical circuit. The fuse amperage should match or exceed the current requirements of the circuit it is protecting. The voltage rating indicates the maximum voltage the fuse can handle, and the size can affect whether the fuse fits properly in the circuit's fuseholder.