Littelfuse 0675002.DRT4P Ceramic Axial Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0675002.DRT4P is a 2A 250VAC ceramic cartridge fuse with axial through-hole mounting. This component is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing system support and component procurement. The fuse is designed for general-purpose circuit protection applications requiring slow-blow response characteristics and ceramic construction for thermal stability.

Substiute Parts

0675002.DRT4P

Littelfuse Inc.In Stock: 9450675002.DRT4P Datasheet

Current PartRFQ

0875002.MRET1P

Littelfuse Inc.In Stock: 8220875002.MRET1P Datasheet

DirectRFQ

0675002.DRT4

Littelfuse Inc.In Stock: 10560675002.DRT4 Datasheet

Parametric EquivalentRFQ

0677002.DRT4

Littelfuse Inc.In Stock: 7550677002.DRT4 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0675002.DRT4P are identified based on strict electrical and mechanical parameter matching. The primary substitution criteria are:

Critical Matching Parameters:

• Current Rating: 2 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Response Time: Slow Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)

Secondary Considerations:

• Physical dimensions and package compatibility
• DC Cold Resistance tolerance
• Melting I²t characteristics
• Regulatory approvals and compliance status

Parameter Comparison

Engineering Selection Recommendations

0875002.MRET1P (Direct Substitute - Recommended)

This part is the primary substitute for the obsolete 0675002.DRT4P. It maintains all critical electrical parameters: 2A current rating, 250V AC voltage rating, ceramic cartridge construction, slow-blow response, and 50A breaking capacity. The part is currently in active production status with ROHS3 compliance and cULus regulatory approval. Physical dimensions differ slightly (0.142" Dia x 0.394" L versus 0.154" Dia x 0.433" L), requiring mechanical fit verification in the target application. DC cold resistance is lower (0.02887 Ohms versus 0.0405 Ohms), and melting I²t is higher (8.45 versus 6.7), indicating marginally faster thermal response. This part is suitable for direct replacement where mechanical envelope permits.

0675002.DRT4 (Parametric Equivalent - Alternative)

This part matches all critical electrical and mechanical parameters with the main part, including identical dimensions and DC cold resistance. It maintains the same 2A/250V rating, ceramic construction, and 50A breaking capacity. The part is in active production status. However, it is RoHS non-compliant, which may restrict use in applications with RoHS requirements. This option is suitable for legacy system support where RoHS compliance is not mandated.

0677002.DRT4 (Parametric Equivalent - Limited Compatibility)

This part shares the same current rating, voltage rating, fuse type, response time, and mounting configuration as the main part. However, the breaking capacity is reduced to 35A (versus 50A), and the melting I²t is significantly higher at 20.8 (versus 6.7), indicating substantially slower thermal response. This part is not recommended as a direct substitute due to the reduced breaking capacity and altered thermal characteristics. Use only if application requirements specifically permit lower breaking capacity and slower response time.

Frequently Asked Questions (FAQ)

Q: Can the 0875002.MRET1P be used as a direct replacement for the 0675002.DRT4P?

A: The 0875002.MRET1P is electrically equivalent and maintains all critical fuse parameters. However, physical dimensions differ: the substitute is 0.142" Dia x 0.394" L compared to 0.154" Dia x 0.433" L. Mechanical fit verification in the target circuit board or fuse holder is required before implementation.

Q: What is the difference between the direct substitute and parametric equivalents?

A: The 0875002.MRET1P is designated as a direct substitute with active production status and modern compliance certifications. The parametric equivalents (0675002.DRT4 and 0677002.DRT4) match electrical specifications but may have different production status, compliance ratings, or thermal characteristics. The 0677002.DRT4 has reduced breaking capacity (35A versus 50A) and is not recommended for direct replacement.

Q: Are there RoHS compliance differences between these parts?

A: Yes. The 0875002.MRET1P is ROHS3 compliant, matching the main part. The parametric equivalents 0675002.DRT4 and 0677002.DRT4 are RoHS non-compliant. Select the ROHS3-compliant option if your application or regulatory environment requires RoHS compliance.

Q: How do the thermal characteristics compare?

A: The main part (0675002.DRT4P) has a melting I²t of 6.7. The direct substitute 0875002.MRET1P has a higher melting I²t of 8.45, indicating slightly slower thermal response. The parametric equivalent 0677002.DRT4 has a melting I²t of 20.8, representing significantly slower response. DC cold resistance also varies: 0.0405 Ohms (main), 0.02887 Ohms (0875002.MRET1P), and 0.035 Ohms (0677002.DRT4).

Q: What regulatory approvals should I consider?

A: The main part carries CSA and UL approvals. The direct substitute 0875002.MRET1P has cULus approval. The parametric equivalents 0675002.DRT4 and 0677002.DRT4 have CSA, UL, and (for 0677002.DRT4) VDE approvals. Verify that the selected part's certifications meet your application's regulatory requirements.

Q: Is the 0677002.DRT4 suitable for my application?

A: The 0677002.DRT4 has a reduced breaking capacity of 35A compared to the 50A of the main part and direct substitute. Use this part only if your application specifications explicitly permit lower breaking capacity and slower thermal response (melting I²t of 20.8 versus 6.7).