Part A
0451007.MRL
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 4553 PCS
- Package
- 2-SMD
- Series
- Fuses
Replacement verdict
Compatible functional replacement candidate
The 0451002.MRL and 0451007.MRL are both fast-acting surface-mount fuses from the same Littelfuse NANO2 series, sharing identical package, voltage rating, and operating temperature range. The primary distinction is the current rating, which must be validated against the actual circuit load requirements before substitution.
Current Rating
Validation required
Voltage Rating
High match
Package Type
High match
Operating Temperature
High match
Parts at a glance
Part B
0451002.MRL
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 4049 PCS
- Package
- 2-SMD
- Series
- Fuses
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 0451002.MRL | 0451007.MRL | Why it matters |
|---|---|---|---|
| Current Rating | 2 A | 7 A | Determines the maximum continuous current the fuse can carry without opening; a direct functional substitutability constraint. |
| Voltage Rating (DC) | 125 V | 125 V | Defines the maximum DC voltage the fuse can safely interrupt; must meet or exceed the circuit voltage. |
| Voltage Rating (AC) | 125 V | 125 V | Defines the maximum AC voltage the fuse can safely interrupt; must meet or exceed the circuit voltage. |
| Interrupting Rating | 50 A @ 125 VAC / 50 A @ 125 VDC | 50 A @ 125 VAC / 50 A @ 125 VDC | Indicates the maximum fault current the fuse can safely break without damage or hazard. |
| Nominal Melting I²t | 1.6 A²s | 17.6 A²s | Represents the energy required to melt the fuse element; affects opening speed and coordination with downstream components. |
| Nominal Voltage Drop | 0.14 V | 0.11 V | Lower voltage drop reduces power loss and heat generation in the circuit. |
| Nominal Cold Resistance | 0.0705 Ohm | 0.0155 Ohm | Affects inrush current behavior and steady-state power dissipation in the application. |
| Fuse Type | Fast-Acting (Nano2) | Fast-Acting (Nano2) | Determines the time-current response; fast-acting fuses protect sensitive components from rapid overcurrent events. |
| Package / Size | Nano2, 6.1 mm x 2.69 mm | Nano2, 6.1 mm x 2.69 mm | Physical footprint and mounting compatibility are essential for drop-in replacement. |
| Operating Temperature Range | -55°C to +125°C | -55°C to +125°C | Ensures reliable operation and proper derating across the application's environmental conditions. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 0451007.MRL | 0451002.MRL |
|---|---|---|
| Series | NANO²® 451 | NANO²® 451 |
| Part Status | Active | Active |
| Mounting Type | Surface Mount | Surface Mount |
| Fuse Type | Board Mount (Cartridge Style Excluded) | Board Mount (Cartridge Style Excluded) |
| Current Rating (Amps) | 7 A | 2 A |
| Voltage Rating - AC | 125 V | 125 V |
| Voltage Rating - DC | 125 V | 125 V |
| Response Time | Fast Blow | Fast Blow |
| Breaking Capacity @ Rated Voltage | 50A | 50A |
| Melting I²t | 10.32 | 0.53 |
| Approval Agency | CSA, PSE, UL | CSA, PSE, UL |
| Operating Temperature | -55°C ~ 125°C | -55°C ~ 125°C |
Frequently asked questions
What are the 0451002.MRL and 0451007.MRL fuses?
The 0451002.MRL and 0451007.MRL are Littelfuse NANO2 surface-mount fuses from the 451 series. The 0451002.MRL is rated 2 A and the 0451007.MRL is rated 7 A. Both are fast-acting ceramic body fuses designed for overcurrent protection on printed circuit boards.
What is the main difference between the 0451002.MRL and 0451007.MRL?
The primary difference is the current rating: the 0451002.MRL is rated 2 A and the 0451007.MRL is rated 7 A. They share the same NANO2 451 series form factor, fast-acting characteristic, and surface-mount package, but they differ in ampere rating and therefore in nominal cold resistance and melting I²t.
Are the 0451002.MRL and 0451007.MRL interchangeable?
No, they are not directly interchangeable. Although both are NANO2 451 series fuses with the same physical package, the 2 A and 7 A current ratings serve different circuit protection levels. Substitution must only be considered after verifying the circuit's normal operating current, inrush profile, and required breaking capacity against the Littelfuse 451 series datasheet.
What is the voltage rating of the 0451002.MRL and 0451007.MRL?
Both the 0451002.MRL and 0451007.MRL are rated 125 V AC and 125 V DC according to the Littelfuse 451 series NANO2 fuse datasheet. The voltage rating must not be exceeded in the application.
What package and mounting type do the 0451002.MRL and 0451007.MRL use?
Both fuses use the NANO2 surface-mount package, which is a compact ceramic body with solderable end terminations. They are designed for reflow soldering on PCB assemblies and are supplied on tape and reel in the .MRL ordering suffix.
What is the breaking capacity of the 0451002.MRL and 0451007.MRL?
The Littelfuse 451 series datasheet specifies a breaking capacity of 50 A at 125 V AC and 50 A at 125 V DC for these NANO2 fuses. This value defines the maximum fault current the fuse can safely interrupt at its rated voltage.
What are the operating temperature limits for the 0451002.MRL and 0451007.MRL?
The Littelfuse 451 series NANO2 fuses are specified for operation from -55 °C to +125 °C. Derating of the current rating may be required at elevated temperatures, so the temperature derating curve in the datasheet should be consulted.
Do the 0451002.MRL and 0451007.MRL carry recognized safety certifications?
Littelfuse 451 series NANO2 fuses are typically recognized under UL 248-14 and certified to CSA standards, with additional approvals depending on the specific rating. Designers should confirm the exact certification status for each ampere rating in the current Littelfuse datasheet or on the manufacturer's product page.