Littelfuse 0672.300DRT4P Equivalent & Substitute Parts

Part Overview

The Littelfuse 0672.300DRT4P is a 300 mA, 250 V AC/DC glass cartridge fuse with axial through-hole mounting. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing system maintenance and new design implementations. The glass construction and fast-blow response characteristics define its primary application profile. Substitute parts must maintain electrical equivalence across current rating, voltage rating, response time, and mechanical compatibility parameters.

Substiute Parts

0672.300DRT4P

Littelfuse Inc.In Stock: 10460672.300DRT4P Datasheet

Current PartRFQ

0874.300MRET1P

Littelfuse Inc.In Stock: 12270874.300MRET1P Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 0672.300DRT4P is based on strict electrical and mechanical parameter matching:

Electrical Equivalence Requirements:

• Current Rating: 300 mA (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)

Mechanical Compatibility Requirements:

• Mounting Type: Through Hole (exact match required)
• Package / Case: Cartridge, Non-Standard (Axial) (exact match required)

Compliance Requirements:

• Approval Agency certifications must be present (CSA, UL, or cULus acceptable)
• RoHS3 Compliance required
• REACH Unaffected status required

The Littelfuse 0874.300MRET1P meets all substitution criteria. While the fuse element material differs (ceramic vs. glass), both constructions satisfy the electrical and mechanical parameters specified for this application category.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0874.300MRET1P is the designated substitute for the obsolete 0672.300DRT4P. Both components carry equivalent electrical ratings (300 mA, 250 V AC, fast-blow response, 50 A breaking capacity) and identical mounting configurations (through-hole, axial cartridge).

The 0874.300MRET1P holds active product status with cULus certification, providing regulatory continuity for applications requiring CSA/UL compliance. Both parts maintain ROHS3 compliance and REACH unaffected status, satisfying environmental and regulatory requirements.

Physical dimensions differ slightly (0874.300MRET1P is marginally smaller), and DC cold resistance and melting I²t values show minor variations due to ceramic vs. glass construction. These differences do not affect functional equivalence within the specified electrical parameters.

Frequently Asked Questions (FAQ)

Q: Can the 0874.300MRET1P directly replace the 0672.300DRT4P in existing designs?

A: Yes. Both components share identical electrical ratings (300 mA, 250 V AC, fast-blow response) and mechanical mounting configurations (through-hole, axial cartridge). The ceramic construction of the substitute does not alter functional performance within the specified parameters.

Q: What is the significance of the fuse element material difference (glass vs. ceramic)?

A: Both glass and ceramic cartridge fuses meet the same electrical and mechanical specifications for this application. The material difference reflects manufacturing evolution; ceramic construction is the current standard for this product category.

Q: Are there compliance differences between the two parts?

A: The main part carries CSA and UL certifications; the substitute carries cULus certification. cULus certification encompasses both Canadian (CSA) and U.S. (UL) standards, providing equivalent regulatory coverage.

Q: Do the dimensional differences affect mechanical fit?

A: The 0874.300MRET1P is slightly smaller (0.142" Dia x 0.394" L vs. 0.154" Dia x 0.433" L). Both maintain the axial cartridge form factor and through-hole mounting compatibility. Verify mechanical clearance in the specific application socket or holder.

Q: What is the inventory status of these parts?

A: The 0672.300DRT4P (obsolete) has 1036 pcs in stock. The 0874.300MRET1P (active) has 1150 pcs in stock, ensuring availability for new procurements and replacements.