Littelfuse 0676.500DRT4P Ceramic Cartridge Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0676.500DRT4P is a 500 mA, 250 V AC 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 and substitute components to maintain design continuity and ensure procurement availability for new production and field replacements.

Substiute Parts

0676.500DRT4P

Littelfuse Inc.In Stock: 9970676.500DRT4P Datasheet

Current PartRFQ

0224.500DRT1P

LittelfuseIn Stock: 9290224.500DRT1P Datasheet

MFR RecommendedRFQ

0674.500DRT4

LittelfuseIn Stock: 8520674.500DRT4 Datasheet

Parametric EquivalentRFQ

0676.500DRT4

Littelfuse Inc.In Stock: 11940676.500DRT4 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 0676.500DRT4P is determined by strict alignment of electrical and mechanical parameters. The primary substitution criteria are:

• Current rating: 500 mA (exact match required)
• Voltage rating (AC): 250 V (exact match required)
• Response time: Fast Blow (exact match required)
• Mounting type: Through Hole (exact match required)
• Physical dimensions and package compatibility

Two categories of substitutes are identified:

Parametric Equivalent (Preferred): The 0676.500DRT4 maintains identical electrical specifications, fuse type (ceramic), and physical dimensions as the obsolete 0676.500DRT4P. This part is active and represents the direct functional replacement.

Functional Substitute (Alternative): The 0224.500DRT1P provides equivalent current and AC voltage ratings with fast-blow response but differs in fuse material (glass vs. ceramic), package type (2AG vs. non-standard axial), and physical dimensions. This substitute is suitable only when mechanical and thermal characteristics of glass fuses are acceptable within the application circuit.

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: 0676.500DRT4

The 0676.500DRT4 is the recommended replacement for the obsolete 0676.500DRT4P. This parametric equivalent maintains identical electrical ratings (500 mA, 250 V AC), fuse type (ceramic), response characteristics (fast blow), and physical dimensions (3.90mm x 11.00mm). Both parts carry CSA and UL approvals. The primary distinction is RoHS compliance status: the obsolete part is ROHS3 compliant while the active replacement is RoHS non-compliant. This difference must be evaluated against specific procurement and regulatory requirements for the end application.

Secondary Selection: 0224.500DRT1P

The 0224.500DRT1P serves as a functional substitute when circuit design permits substitution of fuse material and package type. This glass cartridge fuse maintains the 500 mA current rating and 250 V AC voltage rating with identical fast-blow response. However, the following differences require circuit-level evaluation:

• Fuse material change from ceramic to glass affects thermal and mechanical characteristics
• Physical dimensions increase from 3.90mm x 11.00mm to 4.70mm x 14.48mm, requiring verification of mechanical fit within fuse holder or socket
• DC cold resistance increases from 0.15 Ohms to 0.265 Ohms, affecting circuit impedance
• Melting I²t increases from 0.13 to 0.365, altering thermal response characteristics
• DC voltage rating of 125 V is specified, whereas the ceramic fuses do not specify DC rating

The 0224.500DRT1P carries CE, CSA, and UL approvals and is ROHS3 compliant, providing broader regulatory coverage than the ceramic alternatives.

Frequently Asked Questions (FAQ)

Q: Can the 0676.500DRT4 be used as a direct replacement for the 0676.500DRT4P?

A: Yes. The 0676.500DRT4 is a parametric equivalent with identical current rating (500 mA), AC voltage rating (250 V), fuse type (ceramic), response time (fast blow), and physical dimensions (3.90mm x 11.00mm). Both parts are approved by CSA and UL. The primary consideration is RoHS compliance status, which differs between the two parts.

Q: What are the key differences between the ceramic fuses (0676 series) and the glass fuse (0224.500DRT1P)?

A: The primary differences are fuse material, physical dimensions, and thermal characteristics. Ceramic fuses (0676.500DRT4P and 0676.500DRT4) measure 3.90mm x 11.00mm with melting I²t of 0.13 and DC cold resistance of 0.15 Ohms. The glass fuse (0224.500DRT1P) measures 4.70mm x 14.48mm with melting I²t of 0.365 and DC cold resistance of 0.265 Ohms. Both maintain 500 mA current rating and 250 V AC voltage rating with fast-blow response.

Q: Will the 0224.500DRT1P fit in a socket designed for the 0676.500DRT4P?

A: Physical compatibility must be verified. The 0224.500DRT1P has larger dimensions (0.185" Dia x 0.570" L vs. 0.154" Dia x 0.433" L) and uses a different package type (2AG vs. non-standard axial). Mechanical fit within the existing fuse holder or socket cannot be assumed and requires physical verification or socket redesign.

Q: Are there any compliance or regulatory differences between these substitutes?

A: The 0676.500DRT4P (obsolete) and 0224.500DRT1P are both ROHS3 compliant. The 0676.500DRT4 (active replacement) is RoHS non-compliant. The 0224.500DRT1P carries CE approval in addition to CSA and UL, providing broader regulatory coverage. Specific procurement and end-use requirements must determine which compliance profile is acceptable.

Q: How do the electrical characteristics differ between these fuses?

A: All three fuses maintain the same 500 mA current rating and 250 V AC voltage rating. The ceramic fuses (0676 series) have lower DC cold resistance (0.15 Ohms) and lower melting I²t (0.13) compared to the glass fuse (0.265 Ohms and 0.365 respectively). The glass fuse specifies a 125 V DC rating, while the ceramic fuses do not specify DC voltage. These differences affect circuit impedance and thermal response characteristics.