Littelfuse 0447004.Y Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0447004.Y is a 4 A, 350 V AC / 125 V DC board mount fuse with fast blow response characteristics, designed for through-hole radial mounting in electronic circuits requiring overcurrent protection. This part is classified as obsolete, making identification of active equivalent components necessary for ongoing procurement and design continuity. The substitute part maintains identical electrical and mechanical specifications while offering improved availability and compliance status.

Substiute Parts

0447004.Y

Littelfuse Inc.In Stock: 7740447004.Y Datasheet

Current PartRFQ

0447004.YXP

Littelfuse Inc.In Stock: 11230447004.YXP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Littelfuse 0447004.Y is based on strict equivalence across all critical electrical and mechanical parameters. The substitute part 0447004.YXP is classified as a direct equivalent because it maintains identical specifications in the following key areas:

• Current Rating: 4 A (exact match)
• Voltage Ratings: 350 V AC / 125 V DC (exact match)
• Response Time: Fast Blow (exact match)
• Mounting Configuration: Through Hole Radial (exact match)
• Physical Dimensions: 0.430" L x 0.150" W x 0.404" H (exact match)
• Breaking Capacity: 100 A AC, 50 A DC (exact match)
• Thermal Characteristics: -40°C ~ 125°C operating range (exact match)
• Regulatory Approvals: CSA, METI, UL (exact match)

The primary distinction between the main part and substitute is product status and packaging configuration, not electrical or mechanical performance.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0447004.YXP is the direct substitute for the obsolete 0447004.Y. Selection of the substitute part is based on the following engineering criteria:

• Product Status: The main part is classified as obsolete, while the substitute maintains active status with confirmed inventory availability (1087 pcs in stock).
• Regulatory Compliance: The substitute part achieves ROHS3 compliance and REACH unaffected status, providing enhanced environmental and regulatory alignment compared to the non-compliant main part.
• Electrical Equivalence: All electrical parameters, including current rating, voltage ratings, response time, breaking capacity, and thermal characteristics, are identical between the two parts.
• Mechanical Compatibility: Physical dimensions and mounting configuration are identical, ensuring direct board-level compatibility without design modification.
• Certification Continuity: Both parts maintain identical regulatory approvals (CSA, METI, UL), ensuring no change in certification status or application scope.

The substitute part is suitable for direct replacement in all applications where the main part was originally specified.

Frequently Asked Questions (FAQ)

Q: Can the 0447004.YXP be used as a direct replacement for the 0447004.Y in existing designs?

A: Yes. The substitute part maintains identical electrical specifications (4 A, 350 V AC / 125 V DC), mechanical dimensions (0.430" L x 0.150" W x 0.404" H), and mounting configuration (through-hole radial). No design modification is required.

Q: What is the difference between the main part and the substitute?

A: The primary differences are product status (obsolete vs. active), packaging format (box vs. bulk), and RoHS compliance status (non-compliant vs. ROHS3 compliant). Electrical and mechanical performance are identical.

Q: Are the regulatory approvals the same for both parts?

A: Yes. Both the 0447004.Y and 0447004.YXP carry identical regulatory approvals from CSA, METI, and UL. The substitute part additionally achieves ROHS3 compliance and REACH unaffected status.

Q: What is the operating temperature range for these fuses?

A: Both parts operate across the temperature range of -40°C to 125°C, with identical thermal performance characteristics.

Q: Is the DC cold resistance the same between the two parts?

A: Yes. Both parts have a DC cold resistance of 0.024 Ohms, ensuring identical electrical behavior in circuit applications.

Q: What is the breaking capacity of these fuses?

A: Both parts have a breaking capacity of 100 A AC and 50 A DC at rated voltage, providing identical overcurrent protection performance.