400 mA fast blow in a 2-SMD square end block
The Littelfuse 0451.400MR is a 400 mA fast-blow surface-mount fuse from the NANO² 451 series, rated for 125 V AC and 125 V DC with a breaking capacity of 50 A at rated voltage. The 0.0484 melting I²t and 0.56 ohm cold resistance define the energy-to-clear and steady-state voltage drop — the I²t figure governs inrush withstand for capacitive or inductive loads on the same rail.
Obsolete — sourcing through surplus and last-time-buy channels
The part is available through independent surplus and broker channels; quantities and pricing are confirmed per RFQ.
Approvals and temperature range
CSA and UL approved — the fuse carries agency recognition for use in North American and Canadian equipment.