BlueSea Systems 2023 Catalog CIRCUIT PROTECTION 64 1.518" 38.57mm 1.37" 34.93mm 2.13" 54.23mm 5.17" 131.32mm 4.22" 107.11mm ST-Blade Fuse Blocks Independent Source Consolidates branch circuits and eliminates in-line fuses • Independent source fuse block • Can be used for 24-hour circuits and switched circuit in same block • Screw terminals for securing wires accept ring terminals • Clear insulating cover with label recesses and storage for one fuse, satisfies ABYC/USCG insulation requirements • Easy to open, push button latch for easy access to fuses • Tin-plated copper buses and fuse clips • Fuse Block with cover includes 20 write-on circuit labels and two Terminal Block Jumpers Part # 9217 (p. 103) • Small format standard and custom labels available • Fuses sold separately (p. 57) Part # Circuits Cover 5035 6 Yes 5037 6 - 5035 5037 Related Products Terminal Block Jumpers page 103 ATO or ATC Fuses page 57 easyID ATC Fuses page 57 24-Hour Circuits Two Terminal Block Jumpers included. Optional Two pack available PN 9217 Switched Circuits Terminal Block Jumper Switch Fish Finder GPS Stereo Clock Radio Bilge Pump For the full list of specifications see page 73 Fuse Sizing Best Practices - 80% Rule It is a common misconception that a fuse should be rated for the same amperage as the circuit. Fuses include a metal component designed to heat up when current runs through them. The more current, the hotter the metal gets. When too much current runs through the fuse, the metal heats up enough to separate, breaking the circuit. This means that rating a fuse at the same amperage as the circuit will produce the maximum heat in the fuse without actually breaking the circuit. For this reason the National Electrical Code recommends limiting the amount of current in a circuit to 80% of the fuse rating in that circuit. In other words a 40A fuse would be appropriate for a circuit with a maximum of 32A continuous. This is why you will see many fuse blocks with maximum continuous amperage ratings around 80% of the largest available fuse. Application Diagram Two 24-Hour Circuits and Four Switched Circuits Voltage Max. Operating 32V DC Amperage Max. Operating 30A per circuit Amperage Max. Operating 40A per jumped circuit group Fuse Type ATO or ATC Fuses Screw Terminal #8-32 Screws with captive star lock washer Mounting #8 Screw (M4) TECH TIP