3AP 300-R Equivalent & Substitute Parts

Part Overview

The 3AP 300-R 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 substitute parts essential for ongoing system maintenance and new design implementations. Active alternatives from Littelfuse Inc. and Eaton Electronics Division provide direct functional equivalence while maintaining current product support and availability.

Substiute Parts

3AP 300-R

Bel Fuse Inc.In Stock: 10533AP 300-R 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 eligibility for the 3AP 300-R is determined by strict equivalence across the following parameters: current rating (300 mA), voltage rating (250 V AC), response time (fast blow), package format (3AB/3AG, 1/4" x 1-1/4" axial), fuse type (cartridge, glass), and mounting configuration (through hole). All identified substitute parts meet these core electrical and mechanical requirements. Secondary parameters including breaking capacity, melting I²t, DC cold resistance, and approval agency certifications are provided for engineering evaluation but do not disqualify substitution based on the primary parameter set.

Parameter Comparison

Engineering Selection Recommendations

All three Littelfuse 318 series variants (0318.300HXP, 0318.300MXP, 0318.300VXP) are functionally equivalent substitutes for the 3AP 300-R. These parts maintain active product status, carry CE/CSA/UL certifications, and comply with ROHS3 requirements. The Littelfuse options are preferred for applications requiring current RoHS3 compliance and sustained manufacturer support.

The Eaton BK/AGC-V-3/10 cartridge fuse provides electrical and mechanical equivalence with active product status and CSA/UL certifications. However, this part is RoHS non-compliant and should be selected only for applications where RoHS compliance is not a requirement.

Selection between the three active Littelfuse variants should be based on packaging format availability (all three are supplied in bulk packaging) and inventory requirements. All three Littelfuse parts exhibit identical electrical characteristics and certifications.

Frequently Asked Questions (FAQ)

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

A: Yes. All three Littelfuse 318 series parts are electrically and mechanically identical. They share the same current rating (300 mA), voltage rating (250 V AC), response time (fast blow), package format (3AB/3AG, 1/4" x 1-1/4" axial), and operating temperature range (-55°C ~ 125°C). Selection between them is based on packaging and inventory availability.

Q: What is the primary difference between the Littelfuse 318 series and the Eaton BK/AGC-V-3/10?

A: The primary difference is RoHS compliance status. The Littelfuse 318 series (0318.300HXP, 0318.300MXP, 0318.300VXP) are ROHS3 compliant, while the Eaton BK/AGC-V-3/10 is RoHS non-compliant. All other electrical and mechanical parameters are equivalent. Additionally, the Eaton part has a lower melting I²t value (0.027 versus 0.0689) and lower DC cold resistance (1.084 Ohms versus 1.405 Ohms).

Q: Why does the 3AP 300-R have a higher breaking capacity (200A) than the substitute parts (35A)?

A: Breaking capacity is a secondary parameter that does not affect substitution eligibility. The 3AP 300-R and all substitute parts are functionally equivalent for the specified 300 mA, 250 V AC/DC application. Breaking capacity differences reflect design variations between manufacturers but do not impact performance in standard circuit protection applications.

Q: Are all substitute parts available in the same package format as the original 3AP 300-R?

A: Yes. All substitute parts use the 3AB/3AG package format with 1/4" x 1-1/4" (axial) dimensions. Physical dimensions are nominally equivalent across all parts, with minor variations within manufacturing tolerance (0.266" to 0.275" diameter; 1.280" to 1.292" length).

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

A: For new designs requiring RoHS3 compliance and sustained manufacturer support, any of the three Littelfuse 318 series parts (0318.300HXP, 0318.300MXP, 0318.300VXP) are recommended. For applications without RoHS compliance requirements, the Eaton BK/AGC-V-3/10 is a valid alternative.