Littelfuse 0429.200WRM Surface Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0429.200WRM is a 200 mA, 125 V AC/DC surface mount fuse in 1206 (3216 Metric) package format, designed for board-level circuit protection applications. This component features fast-blow response characteristics and is approved by CSA and UL standards. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

0429.200WRM

Littelfuse Inc.In Stock: 121910429.200WRM Datasheet

Current PartRFQ

0466.200NR

Littelfuse Inc.In Stock: 501280466.200NR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 0429.200WRM is determined by strict equivalence across the following critical parameters:

• Current Rating: 200 mA (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (exact match required)
• Response Time: Fast Blow (exact match required)
• Package / Case: 1206 (3216 Metric) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)
• Approval Agencies: CSA and UL certification (required)

The Littelfuse 0466.200NR meets all substitution criteria and is classified as a direct equivalent. This part maintains identical electrical specifications while offering improved product status and compliance characteristics.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0466.200NR is the direct functional equivalent for the obsolete 0429.200WRM. Both parts maintain identical electrical and thermal specifications, including current rating, voltage ratings, response time, and thermal characteristics. The 0466.200NR is classified as an active product with current manufacturing support and improved compliance status.

The 0466.200NR carries ROHS3 compliance, whereas the 0429.200WRM is non-compliant. For applications subject to RoHS regulations or requiring compliance documentation, the 0466.200NR is the appropriate selection. Both parts are certified by CSA and UL, meeting the same approval standards.

Physical dimensions differ slightly: the 0466.200NR measures 0.023" in height compared to 0.045" for the 0429.200WRM, while maintaining the same 0.125" length and 0.060" width. This reduced profile may provide layout advantages in space-constrained applications. DC cold resistance values differ (1.16 Ohms versus 0.938 Ohms), reflecting design improvements in the newer SlimLine™ 466 series.

Frequently Asked Questions (FAQ)

Q: Can the 0466.200NR be used as a direct replacement for the 0429.200WRM in existing designs?

A: Yes. Both parts share identical current rating (200 mA), voltage ratings (125 V AC/DC), response time (Fast Blow), package format (1206), and mounting type (Surface Mount). Electrical performance is equivalent. The reduced height of the 0466.200NR may require PCB layout verification to confirm clearance compatibility.

Q: What is the significance of the product status difference between these parts?

A: The 0429.200WRM is classified as obsolete, indicating discontinued manufacturing and limited availability. The 0466.200NR is active, ensuring ongoing supply, manufacturing support, and technical documentation availability.

Q: Does the RoHS compliance difference affect substitution eligibility?

A: RoHS compliance is a regulatory and supply chain consideration rather than an electrical performance factor. The 0466.200NR's ROHS3 compliance makes it suitable for applications requiring environmental compliance documentation. The 0429.200WRM remains electrically equivalent but may not satisfy regulatory requirements in certain markets or applications.

Q: Are there any mechanical considerations when substituting these parts?

A: The 0466.200NR is 0.022" shorter in height (0.023" versus 0.045"). Verify that PCB layout, solder paste stencil design, and component placement clearances accommodate this dimensional difference. Both parts use identical 1206 (3216 Metric) footprints.

Q: What certifications apply to both parts?

A: Both the 0429.200WRM and 0466.200NR carry CSA and UL approvals, meeting the same safety and performance standards for circuit protection applications.