Equivalent & Substitute Parts for 3AB 4 Ceramic Fuse

Part Overview

The 3AB 4 is a 4A 250VAC ceramic cartridge fuse manufactured by Bel Fuse Inc., designed for fast-blow protection in AC/DC applications. This fuse requires a dedicated holder (3AB or 3AG type) and is currently classified as obsolete. Due to its obsolete status, identifying compatible substitute parts is essential for system maintenance and component replacement in legacy equipment.

Substiute Parts

3AB 4

Bel Fuse Inc.In Stock: 11523AB 4 Datasheet

Current PartRFQ

3AB 4-R

Bel Fuse Inc.In Stock: 11153AB 4-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 3AB 4 ceramic fuse is determined by strict equivalence across the following critical parameters:

• Current Rating: 4 A (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Response Time: Fast Blow (exact match required)
• Physical Package: 3AB, 3AG, 1/4" x 1-1/4" (exact match required for holder compatibility)
• Breaking Capacity: 200A (exact match required)
• Melting I²t: 36 (exact match required)

The 3AB 4-R from Bel Fuse Inc. meets all these criteria and qualifies as a direct substitute. This part maintains identical electrical and mechanical specifications while offering improved compliance status.

Parameter Comparison

Engineering Selection Recommendations

The 3AB 4-R is the appropriate substitute for the obsolete 3AB 4 ceramic fuse. Both parts are manufactured by Bel Fuse Inc. and maintain identical electrical and mechanical specifications across all critical parameters. The 3AB 4-R offers the following advantages:

• Active product status ensures continued availability and supply chain reliability
• ROHS3 compliance meets current environmental regulations
• Maintained certifications (CE, CSA, cURus, PSE) support regulatory requirements
• Marginally lower DC cold resistance (0.024 Ohms vs. 0.026 Ohms) provides equivalent performance
• Direct physical and electrical compatibility with existing 3AB and 3AG fuse holders

Selection of the 3AB 4-R eliminates obsolescence risk while maintaining full functional equivalence in 250VAC, 4A fast-blow protection applications.

Frequently Asked Questions (FAQ)

Q: Can the 3AB 4-R be used as a direct replacement for the 3AB 4?

A: Yes. The 3AB 4-R is electrically and mechanically identical to the 3AB 4 across all specified parameters, including current rating, voltage rating, response time, breaking capacity, and physical dimensions. It is compatible with all 3AB and 3AG fuse holders.

Q: What is the primary reason to substitute the 3AB 4 with the 3AB 4-R?

A: The 3AB 4 is classified as obsolete, making long-term availability uncertain. The 3AB 4-R maintains active product status, ensuring reliable supply and continued manufacturer support.

Q: Are there any compliance differences between these parts?

A: The 3AB 4-R is ROHS3 compliant, whereas the 3AB 4 is RoHS non-compliant. Both parts maintain equivalent certifications (CE, CSA, PSE) with the 3AB 4-R additionally certified as cURus.

Q: Will the 3AB 4-R fit in existing fuse holders designed for the 3AB 4?

A: Yes. Both parts share identical physical dimensions (0.250" Dia x 1.252" L) and the same package designation (3AB, 3AG, 1/4" x 1-1/4"), ensuring mechanical compatibility with all existing holders.

Q: Is there any difference in electrical performance between the 3AB 4 and 3AB 4-R?

A: No. Both parts have identical current ratings (4A), voltage ratings (250V AC), response time (fast blow), breaking capacity (200A), and melting I²t (36). The DC cold resistance differs marginally (0.026 Ohms vs. 0.024 Ohms), which does not affect functional performance in standard applications.