Fuse carrier box 12 circuits and 1 positive input with lid - Without packaging/notice - Blue Sea Systems

• For ATC/ATO
• Negative bar
• Transparent lid
• Maximum amplification per circuit : 30A
• Max. amplification per parallel circuit: 100A
• Fusibles sold separately

Best practices in fuse size – 80% rule

It is often wrongly believed that a fuse should be designed for the same amplification as the circuit. The fuses include a metallic component designed to heat when the current crosses them. The more current, the warmer the metal. When too much power passes through the fuse, the metal heats enough to separate, cutting the circuit. This means that evaluating a fuse with the same amplification that the circuit will produce the maximum heat in the fuse without actually cutting the circuit. For this reason, the National Electricity Code recommends limiting the amount of current in a circuit to 80% of the nominal value of the fuse in this circuit. In other words, a 40 A fuse would be appropriate for a circuit with a maximum of 32 A continuous. This is why you will see many fusible blocks with maximum continuous intensity of about 80% of the largest available fuse.