3AB 4-R Ceramic Cartridge Fuse - Equivalent & Substitute Parts

Part Overview

The 3AB 4-R is a 4 A, 250 V AC ceramic cartridge fuse manufactured by Bel Fuse Inc. This fast-blow fuse is designed for applications requiring reliable overcurrent protection in AC circuits. The part is actively produced and maintained in inventory, with 1,038 units currently available. Substitute parts are identified when equivalent electrical and mechanical parameters are met, enabling component interchangeability for procurement flexibility and supply chain continuity.

Substiute Parts

3AB 4-R

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

Current PartRFQ

0314004.MXP

Littelfuse Inc.In Stock: 21450314004.MXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3AB 4-R is determined by the following critical parameters:

• Current Rating: 4 A (exact match required)
• Voltage Rating - AC: 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required for mechanical compatibility)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Requires Holder (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (minimum required)

The substitute part 0314004.MXP (Littelfuse Inc., Series 314) meets all critical electrical and mechanical parameters. Additional DC voltage rating and enhanced breaking capacity in the substitute part do not disqualify it from substitution, as these represent equal or superior performance characteristics within the same product category.

Parameter Comparison

Engineering Selection Recommendations

Both the 3AB 4-R and 0314004.MXP are active products with full regulatory compliance. Selection between these parts should be based on:

• Supply availability: The 3AB 4-R has 1,038 units in stock; 0314004.MXP has 2,064 units in stock.
• Approval agency requirements: The 3AB 4-R carries CE, CSA, cURus, and PSE certifications. The 0314004.MXP carries CE, CSA, K-MARK, PSE, and UL certifications. Verify that required certifications align with your application's regulatory requirements.
• Breaking capacity: The 0314004.MXP provides higher breaking capacity (750 A AC, 10 kA DC) compared to the 3AB 4-R (200 A). This represents enhanced performance for high-fault-current applications.
• Melting I²t characteristics: The 0314004.MXP has a lower melting I²t value (10.4 vs. 36), indicating faster thermal response. Confirm compatibility with circuit protection requirements.

Frequently Asked Questions (FAQ)

Q: Can 0314004.MXP be used as a direct replacement for 3AB 4-R?

A: Yes. Both parts share identical current rating (4 A), AC voltage rating (250 V), fuse type (ceramic cartridge), package dimensions (3AB, 3AG, 1/4" x 1-1/4"), and response time (fast blow). Mechanical and electrical compatibility is confirmed.

Q: What is the significance of the DC voltage rating difference?

A: The 3AB 4-R does not specify a DC voltage rating. The 0314004.MXP is rated for 125 V DC, providing additional capability for dual-voltage applications. This does not prevent substitution in AC-only circuits.

Q: How do the melting I²t values affect substitution?

A: Melting I²t determines the thermal energy required to melt the fuse element. The 0314004.MXP (10.4) responds faster than the 3AB 4-R (36). Verify that the faster response time of the substitute part is compatible with your circuit's protection coordination requirements.

Q: Are both parts physically interchangeable in the same holder?

A: Yes. Both parts conform to the 3AB, 3AG package standard with dimensions 1/4" diameter x 1-1/4" length (6.35 mm x 31.75-31.80 mm). Both require a compatible fuse holder for installation.

Q: Which certifications should I prioritize for my application?

A: Identify the regulatory standards required by your end-use application and geographic market. The 3AB 4-R supports CE, CSA, cURus, and PSE. The 0314004.MXP supports CE, CSA, K-MARK, PSE, and UL. Select the part whose certification portfolio matches your requirements.