Littelfuse 0257003.U Automotive Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0257003.U is a 3A 32VDC automotive blade fuse designed for ATO/ATC holder applications. This fuse is classified as obsolete, making identification of active equivalent parts essential for ongoing system maintenance and component procurement. The part operates across a temperature range of -40°C to 105°C and meets cULus approval standards. Due to its obsolete status, sourcing active alternatives with identical electrical and mechanical specifications is necessary for system continuity.

Substiute Parts

0257003.U

Littelfuse Inc.In Stock: 11580257003.U Datasheet

Current PartRFQ

0287003.PXCN

Littelfuse Inc.In Stock: 72320287003.PXCN Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Littelfuse 0257003.U is determined by strict equivalence across the following critical parameters:

• Current Rating: 3 A (exact match required)
• Voltage Rating - DC: 32 V (exact match required)
• Package / Case: Blade, ATO/ATC (exact match required)
• Fuse Type: Automotive (exact match required)
• Breaking Capacity @ Rated Voltage: 1 kA (exact match required)
• Melting I²t: 7.4 (exact match required)
• DC Cold Resistance: 0.0311 Ohms (exact match required)
• Operating Temperature Range: -40°C to 105°C (exact match required)

The substitute part 0287003.PXCN meets all these criteria and is classified as active, making it a direct functional equivalent for the obsolete 0257003.U.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0287003.PXCN is the direct substitute for the obsolete 0257003.U. Both parts are manufactured by Littelfuse Inc. and maintain identical electrical and mechanical specifications across all critical parameters. The substitute part carries active product status, ensuring ongoing availability and supply chain continuity. Both parts comply with ROHS3 standards and meet automotive fuse industry requirements. The 0287003.PXCN is available in bulk packaging with significantly higher inventory levels (7211 pcs vs. 1051 pcs), supporting procurement reliability. UL approval certification on the substitute part provides equivalent regulatory compliance to the cULus approval of the original part.

Frequently Asked Questions (FAQ)

Q: Can the 0287003.PXCN be used as a direct replacement for the 0257003.U in existing applications?

A: Yes. Both parts are identical in current rating (3 A), voltage rating (32 V DC), package type (Blade, ATO/ATC), breaking capacity (1 kA), melting I²t (7.4), and operating temperature range (-40°C to 105°C). Physical dimensions are equivalent within manufacturing tolerance. The substitute part is compatible with all ATO/ATC fuse holders designed for the original part.

Q: What is the difference between the two part numbers?

A: The 0257003.U is obsolete and packaged individually. The 0287003.PXCN is the active equivalent, packaged in bulk. The substitute part is designated as ATOF® series (fast-blow response) versus the ATO® series designation of the original part. Both maintain identical electrical performance and thermal characteristics.

Q: Are there any compliance or certification differences?

A: The original part carries cULus approval. The substitute part carries UL approval. Both certifications meet automotive fuse standards. Both parts are ROHS3 compliant. The substitute part includes REACH Unaffected status, providing additional regulatory documentation.

Q: What are the physical dimension tolerances between the two parts?

A: Original part: 0.750" L x 0.200" W x 0.480" H (19.05mm x 5.08mm x 12.19mm). Substitute part: 0.752" L x 0.201" W x 0.484" H (19.10mm x 5.10mm x 12.30mm). Dimensional variations are within standard manufacturing tolerances for blade fuse construction and do not affect holder compatibility.

Q: Is the substitute part available in the same packaging as the original?

A: The original part is packaged in individual units (500 pc container). The substitute part is available in bulk packaging. For applications requiring individual packaging, bulk quantities can be repackaged to meet specific requirements.