Littelfuse 42005000000 Equivalent & Substitute Parts

Part Overview

The Littelfuse 42005000000 is a 500 mA, 125 V AC / 80 V DC slow blow fuse designed for board mount surface mount applications in the 2410 (6125 Metric) package. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing design support and procurement continuity. The part operates across a temperature range of -55°C to 125°C and carries cURus approval certification.

Substiute Parts

42005000000

Littelfuse Inc.In Stock: 73842005000000 Datasheet

Current PartRFQ

0452.500MRL

Littelfuse Inc.In Stock: 1502150452.500MRL Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Littelfuse 42005000000 is determined by the following critical electrical and mechanical parameters:

Current Rating: 500 mA (exact match required)

Voltage Rating - AC: 125 V (exact match required)

Voltage Rating - DC: Minimum 80 V (substitute may exceed this specification)

Response Time: Slow Blow (exact match required)

Mounting Type: Surface Mount (exact match required)

Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)

Breaking Capacity @ Rated Voltage: 50 A (exact match required)

Operating Temperature Range: -55°C to 125°C (exact match required)

The Littelfuse 0452.500MRL qualifies as a direct substitute based on these parameters. While the substitute part features an enhanced DC voltage rating of 125 V (compared to the original 80 V DC specification), this represents an improvement in capability and does not compromise compatibility. The substitute maintains identical current rating, AC voltage rating, response time, mounting configuration, and thermal operating range.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0452.500MRL is the qualified substitute for the obsolete Littelfuse 42005000000. Selection of this substitute is supported by the following factors:

Product Status: The original part is classified as obsolete, while the substitute is active and maintains current manufacturing support and availability.

Regulatory Compliance: The substitute achieves ROHS3 compliance and REACH unaffected status, addressing modern regulatory requirements. The original part does not meet these standards. Both parts carry recognized safety certifications (cURus for the original; CSA and UR for the substitute).

Electrical Equivalence: The substitute maintains identical current rating (500 mA), AC voltage rating (125 V), response time (Slow Blow), and breaking capacity (50 A). The enhanced DC voltage rating (125 V versus 80 V) provides additional operational margin without introducing compatibility issues.

Thermal Performance: Both parts operate across the identical temperature range of -55°C to 125°C, ensuring thermal equivalence in application environments.

Physical Compatibility: Package geometry differs between the original (2410 / 6125 Metric) and substitute (2-SMD, Square End Block). PCB footprint redesign is required for implementation of the substitute part.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 0452.500MRL directly replace the 42005000000 without PCB modification?

A: No. While the parts are electrically equivalent, the package geometries differ. The original uses a 2410 (6125 Metric) package, while the substitute uses a 2-SMD, Square End Block package. PCB footprint redesign is necessary.

Q: What is the significance of the increased DC voltage rating in the substitute part?

A: The substitute part is rated for 125 V DC compared to the original 80 V DC specification. This represents an enhancement in capability and does not compromise compatibility with circuits designed for the original 80 V DC rating. The substitute will function correctly in all applications where the original part was specified.

Q: Are there any compliance differences between the original and substitute parts?

A: Yes. The substitute part achieves ROHS3 compliance and REACH unaffected status, while the original part is RoHS non-compliant. Both parts carry recognized safety certifications. The substitute is better suited for applications subject to modern regulatory requirements.

Q: What is the current availability status of these parts?

A: The original Littelfuse 42005000000 is obsolete. The substitute Littelfuse 0452.500MRL is active and maintains substantial inventory availability.

Q: Are the electrical characteristics identical between the two parts?

A: Yes. Both parts share identical current rating (500 mA), AC voltage rating (125 V), response time (Slow Blow), breaking capacity (50 A), and operating temperature range (-55°C to 125°C).