Littelfuse 0676004.DRT4P Ceramic Axial Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0676004.DRT4P is a 4A 250VAC ceramic cartridge fuse with fast-blow response characteristics, designed for through-hole mounting in axial configuration. This part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for circuit protection applications requiring identical current and voltage ratings.

Substiute Parts

0676004.DRT4P

Littelfuse Inc.In Stock: 8110676004.DRT4P Datasheet

Current PartRFQ

0876004.MRET1P

Littelfuse Inc.In Stock: 8600876004.MRET1P Datasheet

DirectRFQ

0674004.DRT4

Littelfuse Inc.In Stock: 9550674004.DRT4 Datasheet

Parametric EquivalentRFQ

0676004.DRT4

Littelfuse Inc.In Stock: 11450676004.DRT4 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 0676004.DRT4P is determined by the following critical parameters:

• Current Rating: 4 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Cartridge, Non-Standard (Axial) (exact match required)

Substitute parts are grouped into two categories:

Direct Manufacturer Substitute: Parts with identical electrical characteristics and active product status, differing only in packaging format or minor dimensional tolerances within acceptable mechanical compatibility ranges.

Parametric Equivalent: Parts meeting all critical electrical parameters with active product status, but with variations in breaking capacity, melting I²t, or compliance certifications that may affect application suitability.

Parameter Comparison

Engineering Selection Recommendations

0876004.MRET1P (Direct Manufacturer Substitute - Recommended for Active Designs)

This part is the primary substitute for new designs and production replacements. It maintains identical electrical ratings (4A, 250VAC, Fast Blow) and breaking capacity (40A). The part is active with ROHS3 compliance and carries cULus and VDE certifications. Dimensional variation (0.142" Dia x 0.394" L versus 0.154" Dia x 0.433" L) requires mechanical fit verification in existing PCB footprints or through-hole mounting hardware. The specified operating temperature range (-55°C ~ 125°C) provides defined thermal performance. Packaging format is Tape & Reel (TR), suitable for automated assembly processes.

0676004.DRT4 (Parametric Equivalent - Alternative for Compliance-Critical Applications)

This part matches the main part's electrical specifications and maintains identical dimensions (0.154" Dia x 0.433" L). It is active with full certification coverage (CCC, CSA, UL, VDE) matching the obsolete part's approval agencies. However, RoHS non-compliance status differs from the main part's ROHS3 compliance, requiring compliance verification against application requirements. This part is suitable for legacy system maintenance where dimensional and certification compatibility is prioritized.

0674004.DRT4 (Parametric Equivalent - Limited Substitution)

This part meets core electrical requirements (4A, 250VAC, Fast Blow) but differs in breaking capacity (50A versus 40A) and melting I²t (8.96 versus 14.6). These differences indicate different thermal response characteristics. RoHS non-compliance and reduced certification coverage (CSA, UL only) further limit applicability. This part is suitable only where increased breaking capacity is acceptable and compliance requirements align with CSA and UL standards.

Frequently Asked Questions (FAQ)

Q: Can 0876004.MRET1P be used as a direct replacement for 0676004.DRT4P in existing assemblies?

A: Electrical compatibility is confirmed (4A, 250VAC, Fast Blow, 40A breaking capacity). Mechanical compatibility requires verification due to dimensional differences: 0876004.MRET1P is 0.142" Dia x 0.394" L versus the original 0.154" Dia x 0.433" L. PCB footprint and mounting hardware clearances must be assessed before implementation.

Q: What is the significance of the melting I²t difference between 0876004.MRET1P (14.64) and 0674004.DRT4 (8.96)?

A: Melting I²t defines the thermal energy required to melt the fuse element. Lower I²t values indicate faster thermal response. The 0674004.DRT4 will respond more quickly to overcurrent conditions, which may affect circuit protection coordination in systems designed for the original part's thermal characteristics.

Q: Does the RoHS compliance difference affect substitution eligibility?

A: RoHS compliance is a regulatory and supply chain requirement, not an electrical performance parameter. The 0876004.MRET1P (ROHS3 compliant) is preferred for new designs and applications subject to RoHS regulations. The 0674004.DRT4 and 0676004.DRT4 (RoHS non-compliant) are suitable only where RoHS exemptions apply or legacy compliance standards are acceptable.

Q: Why is 0876004.MRET1P packaged in Tape & Reel format while the main part has no specified packaging?

A: Tape & Reel (TR) packaging is standard for automated assembly and high-volume production. The main part's unspecified packaging suggests bulk or tube packaging for lower-volume applications. Both formats contain identical components; packaging selection depends on assembly process requirements.

Q: Are all substitute parts certified by the same agencies as the original 0676004.DRT4P?

A: No. The original part carries CCC, CSA, UL, and VDE certifications. The 0876004.MRET1P carries cULus and VDE certifications (subset). The 0674004.DRT4 carries CSA and UL certifications (subset). The 0676004.DRT4 carries CCC, CSA, UL, and VDE certifications (full match). Application requirements determine whether reduced certification coverage is acceptable.