Littelfuse 0257020.U Automotive Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0257020.U is a 20A 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 delivers fast-blow response characteristics suitable for automotive electrical protection circuits requiring 20-ampere current limiting at 32 volts DC.

Substiute Parts

0257020.U

Littelfuse Inc.In Stock: 9720257020.U Datasheet

Current PartRFQ

0287020.PXCN

Littelfuse Inc.In Stock: 2673440287020.PXCN Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete Littelfuse 0257020.U is determined by strict equivalence across the following parameters:

• Current Rating: 20 A (exact match required)
• Voltage Rating - DC: 32 V (exact match required)
• Package / Case: Blade, ATO/ATC (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 1kA (exact match required)
• Melting I²t: 520 (exact match required)
• Operating Temperature Range: -40°C ~ 105°C (exact match required)
• DC Cold Resistance: 0.00338 Ohms (exact match required)

The substitute part Littelfuse 0287020.PXCN meets all electrical and mechanical parameters required for direct replacement in ATO/ATC holder applications.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0287020.PXCN is the direct active equivalent for the obsolete 0257020.U. Both parts are manufactured by Littelfuse Inc. and maintain identical electrical and mechanical specifications across all critical parameters. The 0287020.PXCN carries active product status with UL approval certification, ensuring continued availability and compliance support. Both parts are ROHS3 compliant and suitable for automotive electrical protection applications requiring 20-ampere fast-blow response at 32 volts DC in ATO/ATC holder configurations.

Frequently Asked Questions (FAQ)

Q: Can the 0287020.PXCN directly replace the 0257020.U without modification?

A: Yes. The 0287020.PXCN is a direct replacement. All electrical parameters (current rating, voltage rating, response time, breaking capacity, melting I²t, and DC cold resistance) are identical. The physical dimensions are equivalent within manufacturing tolerance (0.750" vs 0.752" length; 0.200" vs 0.201" width; 0.480" vs 0.484" height). Both parts fit standard ATO/ATC holder applications without modification.

Q: What is the significance of the product status change from Obsolete to Active?

A: The obsolete status of 0257020.U indicates it is no longer manufactured or supported. The 0287020.PXCN maintains active product status, ensuring ongoing availability, technical support, and compliance documentation from Littelfuse Inc.

Q: Are there differences in approval certifications between these parts?

A: The 0257020.U carries cULus approval, while the 0287020.PXCN carries UL approval. Both certifications are recognized standards for automotive electrical components. The 0287020.PXCN's UL certification provides current regulatory compliance.

Q: What packaging options are available for the 0287020.PXCN?

A: The 0287020.PXCN is supplied in bulk packaging, differing from the 0257020.U which was supplied in 500-piece packaging. Procurement quantities should be adjusted accordingly based on application requirements.

Q: Are both parts RoHS compliant?

A: Yes. Both the 0257020.U and 0287020.PXCN are ROHS3 compliant, meeting environmental and material restriction requirements for automotive applications.