3AP 300 Equivalent & Substitute Parts

Part Overview

The 3AP 300 is a 300 mA 250 V AC/DC fast-blow glass cartridge fuse manufactured by Bel Fuse Inc. in the 3AB/3AG package format (1/4" x 1-1/4" axial). This component is classified as obsolete, making identification of functionally equivalent active alternatives essential for ongoing system maintenance and new design implementations. Substitute parts must maintain identical electrical ratings, mechanical dimensions, and performance characteristics to ensure direct compatibility in existing circuit protection applications.

Substiute Parts

3AP 300

Bel Fuse Inc.In Stock: 9733AP 300 Datasheet

Current PartRFQ

0318.300HXP

Littelfuse Inc.In Stock: 9840318.300HXP Datasheet

SimilarRFQ

0318.300MXP

Littelfuse Inc.In Stock: 8580318.300MXP Datasheet

SimilarRFQ

0318.300VXP

Littelfuse Inc.In Stock: 9470318.300VXP Datasheet

SimilarRFQ

BK/AGC-V-3/10

Eaton - Electronics DivisionIn Stock: 1052BK/AGC-V-3/10 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution validity for the 3AP 300 is determined by strict equivalence across the following parameters:

• Current Rating: 300 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (Axial) (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (minimum requirement)

All substitute parts listed below satisfy these mandatory criteria. Secondary parameters including breaking capacity, melting I²t, DC cold resistance, and regulatory compliance status are provided for engineering evaluation but do not disqualify substitution eligibility.

Parameter Comparison

Engineering Selection Recommendations

All four substitute parts (0318.300HXP, 0318.300MXP, 0318.300VXP, and BK/AGC-V-3/10) are functionally equivalent to the 3AP 300 and satisfy the mandatory electrical and mechanical substitution criteria.

The Littelfuse 318 series parts (0318.300HXP, 0318.300MXP, 0318.300VXP) are active products with ROHS3 compliance and full CE/CSA/UL certification. These three variants are interchangeable and represent the primary recommendation for new designs and ongoing production requiring RoHS compliance.

The Eaton BK/AGC-V-3/10 is an active product with CSA and UL certification. This part does not carry RoHS3 compliance status. Selection of this alternative should be based on specific application requirements and regulatory environment.

The 3AP 300 original part carries PSE approval in addition to CE/CSA/UL certifications. Applications requiring PSE certification should evaluate substitute part certifications against regional regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 0318.300HXP, 0318.300MXP, and 0318.300VXP be used interchangeably?

A: Yes. All three Littelfuse variants share identical electrical ratings (300 mA, 250 V AC), fuse type (cartridge glass, fast blow), package format (3AB/3AG, 1/4" x 1-1/4" axial), and operating temperature range (-55°C ~ 125°C). They are direct substitutes for one another.

Q: What is the difference between the Littelfuse and Eaton substitute options?

A: The primary differences are RoHS compliance status and regulatory certifications. Littelfuse 318 series parts are ROHS3 compliant with CE/CSA/UL approval. The Eaton BK/AGC-V-3/10 is not ROHS3 compliant but carries CSA/UL approval. Both meet the mandatory electrical and mechanical substitution criteria.

Q: Are there dimensional differences between the 3AP 300 and substitute parts?

A: Minor dimensional variations exist within the 3AB/3AG package specification. The 3AP 300 measures 0.272" diameter x 1.280" length. Littelfuse variants measure 0.275" diameter x 1.288" length. The Eaton part measures 0.266" diameter x 1.292" length. These variations fall within standard package tolerances and do not affect mechanical compatibility in through-hole mounting applications.

Q: Does the difference in breaking capacity affect substitution validity?

A: The 3AP 300 specifies 200A breaking capacity, while all substitute parts specify 35A. Breaking capacity represents the maximum fault current the fuse can safely interrupt. Application of substitute parts in circuits where fault current may exceed 35A requires circuit design evaluation. For standard circuit protection applications within the 35A breaking capacity limit, substitution is valid.

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

A: For new designs requiring RoHS compliance, the Littelfuse 318 series (0318.300HXP, 0318.300MXP, or 0318.300VXP) is the appropriate selection. For applications with specific regulatory or certification requirements, evaluate the approval agency certifications listed in the parameter comparison table against application requirements.