Equivalent & Substitute Parts for 3AB 7 Ceramic Fuse

Part Overview

The 3AB 7 is a 7A 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 features a 1/4" x 1-1/4" form factor. The main part number 3AB 7 is currently listed as obsolete, making identification of active equivalent parts essential for ongoing system maintenance and new designs.

Substiute Parts

3AB 7

Bel Fuse Inc.In Stock: 11843AB 7 Datasheet

Current PartRFQ

3AB 7-R

Bel Fuse Inc.In Stock: 14763AB 7-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 3AB 7 ceramic fuse is determined by strict equivalence across the following critical parameters:

• Current Rating: 7 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)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required for holder compatibility)
• Breaking Capacity: 200A (exact match required)
• Melting I²t: 141 (exact match required)

The substitute part 3AB 7-R meets all these criteria and is manufactured by the same supplier (Bel Fuse Inc.), ensuring mechanical and electrical compatibility with existing 3AB/3AG holders.

Parameter Comparison

Engineering Selection Recommendations

The 3AB 7-R is the direct active equivalent for the obsolete 3AB 7 ceramic fuse. Selection of the 3AB 7-R is based on:

• Identical electrical and mechanical specifications across all critical parameters
• Active product status ensuring continued availability and supply chain reliability
• Enhanced regulatory compliance: ROHS3 certification (versus non-compliant status of the main part)
• Maintained approval certifications (CE, CSA, cULus, PSE) suitable for the same applications
• Same manufacturer (Bel Fuse Inc.) guaranteeing consistency in design and performance

For applications requiring RoHS compliance or new designs, the 3AB 7-R is the appropriate selection. For legacy systems currently using 3AB 7, direct replacement with 3AB 7-R maintains full functional and mechanical compatibility.

Frequently Asked Questions (FAQ)

Q: Can the 3AB 7-R be used as a direct replacement for the 3AB 7?

A: Yes. The 3AB 7-R is electrically and mechanically identical to the 3AB 7 across all specified parameters, including current rating, voltage rating, fuse type, response time, package dimensions, and breaking capacity. It installs in the same 3AB/3AG holder without modification.

Q: What is the difference between 3AB 7 and 3AB 7-R?

A: The primary differences are product status and compliance. The 3AB 7 is obsolete and RoHS non-compliant, while the 3AB 7-R is an active product with ROHS3 compliance. Both maintain identical electrical and mechanical performance.

Q: Are there any compatibility concerns when switching from 3AB 7 to 3AB 7-R?

A: No compatibility concerns exist. Both fuses share identical dimensions (0.250" Dia x 1.252" L), holder requirements (3AB, 3AG), and electrical characteristics. The 3AB 7-R is a direct form-fit-function replacement.

Q: What holder types are compatible with the 3AB 7-R?

A: The 3AB 7-R requires a 3AB or 3AG type holder, identical to the 3AB 7. The 1/4" x 1-1/4" form factor ensures compatibility with all standard holders designed for this cartridge fuse series.

Q: Does the 3AB 7-R meet current regulatory requirements?

A: Yes. The 3AB 7-R holds ROHS3 compliance and maintains all relevant approval certifications (CE, CSA, cULus, PSE), making it suitable for applications with modern regulatory requirements.