Bel Fuse Inc. 3ABP 4 Ceramic Cartridge Fuse - Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 3ABP 4 is a 4 A, 250 V AC ceramic cartridge fuse with fast-blow response characteristics, designed for through-hole mounting in 3AB/3AG form factor. This component is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system maintenance and new design implementations. Littelfuse Inc. Series 324 fuses provide direct electrical and mechanical compatibility as substitute options.

Substiute Parts

3ABP 4

Bel Fuse Inc.In Stock: 10113ABP 4 Datasheet

Current PartRFQ

0324004.HXP

Littelfuse Inc.In Stock: 11540324004.HXP Datasheet

DirectRFQ

0324004.MXP

Littelfuse Inc.In Stock: 44160324004.MXP Datasheet

DirectRFQ

0324004.VXP

Littelfuse Inc.In Stock: 8050324004.VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3ABP 4 with Littelfuse 324 series fuses (0324004.HXP, 0324004.MXP, 0324004.VXP) is based on the following matched electrical and mechanical parameters:

• Current Rating: 4 A (identical)
• Voltage Rating - AC: 250 V (identical)
• Fuse Type: Cartridge, Ceramic (identical)
• Response Time: Fast Blow (identical)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (Axial) (identical)
• Mounting Type: Through Hole (identical)
• Operating Temperature Range: -55°C ~ 125°C (identical)
• Physical Dimensions: 0.275" Dia x 1.288" L (6.99mm x 32.72mm) - within acceptable tolerance for 3AB/3AG form factor

The Littelfuse alternatives provide enhanced DC voltage rating (125 V DC) and superior breaking capacity specifications compared to the obsolete Bel Fuse part, while maintaining full AC circuit protection equivalence.

Parameter Comparison

Engineering Selection Recommendations

All three Littelfuse 324 series alternatives (0324004.HXP, 0324004.MXP, 0324004.VXP) are suitable direct substitutes for the obsolete 3ABP 4. Selection among these three variants should be based on:

Product Availability: 0324004.MXP offers the highest inventory level (4400 pcs), followed by 0324004.HXP (1051 pcs) and 0324004.VXP (702 pcs).

Regulatory Compliance: All three Littelfuse alternatives maintain ROHS3 compliance and active product status, addressing the non-compliance status of the original Bel Fuse component. Certification coverage differs slightly: 0324004.HXP and 0324004.MXP include K-MARK certification, while 0324004.VXP includes KC certification.

Performance Enhancement: The Littelfuse substitutes provide superior breaking capacity (750 A AC, 10 kA DC versus 200 A) and explicit DC voltage rating (125 V), offering enhanced circuit protection margins in applications requiring DC operation.

Mechanical Compatibility: Physical dimensions are within acceptable tolerance for 3AB/3AG form factor compatibility. All alternatives maintain identical current rating, AC voltage rating, response time, and operating temperature range.

Frequently Asked Questions (FAQ)

Q: Can Littelfuse 324 series fuses directly replace the Bel Fuse 3ABP 4 in existing circuits?

A: Yes. The Littelfuse alternatives match all critical electrical parameters: 4 A current rating, 250 V AC voltage rating, fast-blow response, and 3AB/3AG form factor. Physical dimensions are within acceptable tolerance for through-hole mounting compatibility.

Q: What is the significance of the melting I²t difference between the original and substitute parts?

A: The Littelfuse substitutes have lower melting I²t values (10.4 versus 36), indicating faster thermal response. This represents an improvement in circuit protection characteristics and does not compromise compatibility in applications designed for 4 A fast-blow fuses.

Q: Are there DC voltage considerations when substituting?

A: The original 3ABP 4 does not specify DC voltage rating. The Littelfuse alternatives explicitly rate 125 V DC, providing defined DC circuit protection capability. For AC-only applications, this additional specification does not affect compatibility.

Q: How do the three Littelfuse variants differ from each other?

A: The three Littelfuse part numbers (0324004.HXP, 0324004.MXP, 0324004.VXP) are electrically and mechanically identical. Differences are limited to packaging designation and regulatory certifications: 0324004.HXP and 0324004.MXP include K-MARK, while 0324004.VXP includes KC certification. Selection should be based on inventory availability and regional certification requirements.

Q: What is the impact of RoHS compliance on substitution?

A: The original 3ABP 4 is RoHS non-compliant, while all Littelfuse alternatives are ROHS3 compliant. For new designs or systems subject to RoHS regulations, the Littelfuse substitutes provide regulatory alignment without functional compromise.

Q: Are the physical dimensions identical between the original and substitute parts?

A: Dimensions are within acceptable tolerance for 3AB/3AG form factor. Original: 0.272" Dia x 1.280" L; Littelfuse alternatives: 0.275" Dia x 1.288" L. These minor variations remain within standard mechanical compatibility for through-hole mounting in 3AB/3AG fuse holders.