Equivalent & Substitute Parts for 3AG 4.6 Fuse

Part Overview

The 3AG 4.6 is a 4.6 A, 250 V AC/DC fast-blow glass cartridge fuse manufactured by Bel Fuse Inc. This component is classified as obsolete, necessitating identification of active equivalent and substitute parts for ongoing circuit protection applications. The fuse requires a compatible holder (3AB or 3AG type) and is designed for standard electrical protection in equipment rated up to 250 V AC.

Substiute Parts

3AG 3.5

Bel Fuse Inc.In Stock: 9303AG 3.5 Datasheet

Current PartRFQ

3AG 3.5-R

Bel Fuse Inc.In Stock: 23813AG 3.5-R Datasheet

DirectRFQ

FSA-3.5A

OptiFuseIn Stock: 4941FSA-3.5A Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3AG 4.6 fuse is determined by the following critical parameters:

• Current Rating: Must be 4.6 A
• Voltage Rating (AC): Must be 250 V minimum
• Fuse Type: Must be Cartridge, Glass
• Response Time: Must be Fast Blow
• Package / Case: Must be 3AB, 3AG, 1/4" x 1-1/4" (6.35mm x 31.80mm)
• Mounting Type: Must require compatible holder

All identified substitute parts meet these core electrical and mechanical requirements, ensuring direct functional compatibility within the same circuit protection application.

Parameter Comparison

Engineering Selection Recommendations

3AG 4.6-R (Bel Fuse Inc.): This part is the direct manufacturer equivalent of the obsolete 3AG 4.6. It maintains identical electrical specifications, package dimensions, and breaking capacity while offering active product status and ROHS3 compliance. The DC cold resistance is marginally lower (0.027 Ohms vs. 0.03 Ohms), representing improved performance characteristics. Approval agencies include CE, CSA, cURus, and PSE. This is the primary replacement for legacy 3AG 4.6 applications.

FSA-4.6A (OptiFuse): This parametric equivalent meets all core electrical and mechanical substitution criteria. It is ROHS3 compliant and carries cULus and UL 248 certifications. The breaking capacity is rated at 100A (compared to 200A for the Bel Fuse alternatives) and the melting I²t is 32.15 (compared to 28). These differences indicate a different thermal response profile. This part is suitable for applications where the lower breaking capacity and higher melting I²t are acceptable within the circuit design.

Frequently Asked Questions (FAQ)

Q: Can the 3AG 4.6-R be used as a direct replacement for the obsolete 3AG 4.6?

A: Yes. The 3AG 4.6-R is manufactured by the same company (Bel Fuse Inc.) and maintains identical current rating, voltage rating, fuse type, response time, package dimensions, and breaking capacity. It is the recommended direct replacement.

Q: What is the difference between the 3AG 4.6-R and FSA-4.6A?

A: Both parts share the same current rating (4.6 A), voltage rating (250 V), fuse type (Cartridge, Glass), response time (Fast Blow), and package dimensions. The FSA-4.6A has a lower breaking capacity (100A vs. 200A) and a higher melting I²t (32.15 vs. 28). These differences affect the fuse's thermal and electrical response characteristics under fault conditions.

Q: Are all substitute parts compatible with the same holder?

A: Yes. All three parts use the 3AB, 3AG package type with identical dimensions (0.250" Dia x 1.252" L / 6.35mm x 31.80mm), ensuring mechanical compatibility with standard 3AG-type fuse holders.

Q: What are the RoHS compliance differences?

A: The original 3AG 4.6 is RoHS non-compliant. Both substitute parts (3AG 4.6-R and FSA-4.6A) are ROHS3 compliant, meeting current environmental regulations for new designs and procurement.

Q: Which substitute part should be selected for new designs?

A: For new designs requiring direct electrical equivalence with the original 3AG 4.6 specifications, the 3AG 4.6-R is recommended. For applications where the FSA-4.6A's lower breaking capacity and higher melting I²t are acceptable, it provides an alternative from a different manufacturer with equivalent core functionality.