If a lower current rating, or a lower time delay rating is used, the fuse may open under normal
circuit conditions. Substitute fuses must have the same style (physical dimensions) as the
PROPER FIT between the fuse and fuseholder is essential. If the clips on clip-type fuseholders are
sprung, the clips should be reformed, or clip clamps should be used. Any corrosion on fuses or
fuseholders must be removed with fine sandpaper.
PREVENTIVE MAINTENANCE of fuses involves checking for the proper fuse, corrosion, proper
fit, and open fuses; and correcting any discrepancies.
CIRCUIT BREAKERS have five main components: The frame, the operating mechanism, the arc
extinguisher, the terminal connectors, and the trip element.