Littelfuse 042901.5WRM Surface Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 042901.5WRM is a 1.5 A, 63 V AC/DC surface mount board fuse in 1206 (3216 Metric) package format with fast blow response characteristics. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing design support and production continuity. The part operates across a temperature range of -55°C to 90°C and is designed for direct board mounting applications requiring fast-acting overcurrent protection.

Substiute Parts

042901.5WRM

Littelfuse Inc.In Stock: 9633042901.5WRM Datasheet

Current PartRFQ

046601.5NR

LittelfuseIn Stock: 105384046601.5NR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 042901.5WRM is determined by strict equivalence across the following critical parameters:

• Current Rating: 1.5 A (exact match required)
• Voltage Rating: 63 V AC and 63 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)
• Operating Temperature Range: -55°C to 90°C (minimum requirement)

The Littelfuse 046601.5NR meets all substitution criteria. This part belongs to the SlimLine™ 466 series and maintains identical electrical specifications while offering improved product status (Active) and enhanced compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 046601.5NR is the direct substitute for the obsolete 042901.5WRM. Selection of the 046601.5NR is supported by the following factors:

• Electrical equivalence across all critical parameters (current, voltage, response time)
• Active product status ensuring long-term availability and supply chain continuity
• ROHS3 compliance, addressing modern regulatory requirements
• CSA and UL approvals, providing recognized safety certifications
• Identical package footprint and mounting characteristics, enabling direct board-level substitution
• Reduced physical height (0.023" vs 0.045"), offering improved PCB design flexibility

The 046601.5NR maintains functional and mechanical compatibility while providing enhanced compliance and certification status relative to the obsolete original part.

Frequently Asked Questions (FAQ)

Q: Can the 046601.5NR be used as a direct replacement for the 042901.5WRM on existing PCBs?

A: Yes. Both parts share identical electrical specifications (1.5 A, 63 V AC/DC, Fast Blow response) and package dimensions (1206 / 3216 Metric). The 046601.5NR has a reduced height (0.023" vs 0.045"), which does not affect PCB compatibility.

Q: What are the key differences between these two parts?

A: The primary differences are product status (Obsolete vs Active), compliance certifications (RoHS non-compliant vs ROHS3 Compliant), and approval agencies (none specified vs CSA, UL). Electrical and mechanical specifications are identical.

Q: Is the 046601.5NR available in the same packaging as the 042901.5WRM?

A: The 046601.5NR is supplied in Tape & Reel (TR) packaging, which is standard for high-volume production. The original part packaging specification was not provided in the available data.

Q: Are there any thermal or environmental considerations when substituting these parts?

A: Both parts operate across the same temperature range (-55°C to 90°C) and share identical moisture sensitivity levels (MSL 1 - Unlimited). No thermal or environmental derating adjustments are required.

Q: What certifications does the 046601.5NR carry?

A: The 046601.5NR holds CSA and UL approvals, providing recognized safety certifications for board-mounted fuse applications. The original part carried no specified approvals.