Littelfuse Inc. NANO²® 451 series, Board Mount (Cartridge Style Excluded) fuse, 0451.500MRSN, 500 mA, 125 VAC, 50 A breaking capacity, Fast Blow, 2-SMD Square End Block package, Tape & Reel.
| Parameter | Value |
|---|---|
| Series | NANO²® 451 |
| Fuse type | Board Mount (Cartridge Style Excluded) |
| Mounting | Surface Mount |
| Voltage rating - AC | 125 V |
| Breaking capacity @ rated voltage | 50A |
| Current rating | 500 mA |
| Response time | Fast Blow |
| Operating temperature | -55°C ~ 125°C |
| Size (Dimension) | 0.240\" L x 0.106\" W x 0.106\" H (6.10mm x 2.69mm x 2.69mm) |
| Approval agency | CSA, UR |
| Package | Tape & Reel (TR) |
| Melting i2t | 0.0795 |
| Case | 2-SMD, Square End Block |
| DC cold resistance | 0.42 Ohms |
The Littelfuse 0451.500MRSN is a 500 mA fast-blow surface-mount fuse from the NANO²® 451 series, rated for 125 VAC with a 50 A breaking capacity at rated voltage. The 0.0795 melting I²t and 0.42 Ohms DC cold resistance define the energy-to-clear and voltage drop in the circuit — the low I²t keeps downstream silicon safe during a fault, while the resistance matters for IR-drop in low-voltage rails.
The fuse is rated for 50 A breaking capacity at 125 VAC — it safely interrupts a fault current up to that level without rupturing or sustaining an arc.