3AP 750 Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The 3AP 750 is a 750 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 equivalent substitute parts necessary for ongoing system maintenance and new design implementations. Active alternatives from Littelfuse Inc. provide direct functional equivalence while offering current product availability and updated compliance certifications.

Substiute Parts

3AP 750

Bel Fuse Inc.In Stock: 11303AP 750 Datasheet

Current PartRFQ

0318.750HXP

Littelfuse Inc.In Stock: 8350318.750HXP Datasheet

SimilarRFQ

0318.750MXP

Littelfuse Inc.In Stock: 11420318.750MXP Datasheet

SimilarRFQ

0318.750VXP

Littelfuse Inc.In Stock: 11100318.750VXP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3AP 750 is determined by strict equivalence across the following parameters:

• Current Rating: 750 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Response Time: Fast Blow (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (Axial) (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Mounting Type: Through Hole (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)

All three Littelfuse 318 series parts (0318.750HXP, 0318.750MXP, 0318.750VXP) meet these criteria and are qualified as direct substitutes for the 3AP 750.

Parameter Comparison

Engineering Selection Recommendations

All three Littelfuse 318 series substitutes (0318.750HXP, 0318.750MXP, 0318.750VXP) provide functional equivalence to the obsolete 3AP 750. Selection among these three active alternatives should be based on:

Product Availability: All three Littelfuse parts are in active production status with current inventory availability (818–1063 pieces in stock), compared to the 3AP 750's obsolete status.

Compliance Posture: The Littelfuse substitutes carry ROHS3 compliance certification, addressing modern regulatory requirements. The original 3AP 750 is RoHS non-compliant. Both the original and substitutes maintain CE, CSA, and UL certifications.

Electrical Performance Variance: The Littelfuse substitutes exhibit higher melting I²t values (1.84 versus 0.75) and lower breaking capacity ratings (35A versus 200A) compared to the 3AP 750. These differences reflect design variations between manufacturers but do not affect substitution eligibility within the specified electrical and mechanical parameter constraints.

Packaging: All substitutes are supplied in bulk packaging format, consistent with standard component procurement practices.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 0318.750HXP, 0318.750MXP, and 0318.750VXP be used interchangeably with the 3AP 750?

A: Yes. All three Littelfuse parts meet the substitution criteria: identical current rating (750 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), mounting type (through hole), and operating temperature range (-55°C to 125°C).

Q: What is the difference between the three Littelfuse substitute options?

A: The 0318.750HXP, 0318.750MXP, and 0318.750VXP are functionally equivalent across all specified electrical and mechanical parameters. Differentiation between these part numbers reflects internal Littelfuse product line segmentation and packaging designations. Selection should be based on supplier availability and procurement requirements.

Q: Why does the 3AP 750 have a higher breaking capacity (200A) than the Littelfuse substitutes (35A)?

A: Breaking capacity represents the maximum current the fuse can safely interrupt without rupturing the fuse body. This parameter varies by manufacturer design and does not affect the fuse's primary function of protecting circuits at its rated current (750 mA). Both designs are suitable for applications within the specified electrical parameters.

Q: Are there compliance differences between the original 3AP 750 and the Littelfuse substitutes?

A: The original 3AP 750 is RoHS non-compliant, while all three Littelfuse substitutes carry ROHS3 compliance certification. Both maintain CE, CSA, and UL approvals. For new designs or systems requiring RoHS compliance, the Littelfuse substitutes are the appropriate choice.

Q: Can I use these fuses in applications rated for 250 V DC?

A: The specified voltage rating is 250 V AC. The fuses are rated for AC/DC operation at this voltage level. Confirmation of DC suitability for your specific application circuit should be verified against the fuse manufacturer's technical documentation.

Q: What is the physical size tolerance between the 3AP 750 and Littelfuse substitutes?

A: The 3AP 750 measures 0.272" diameter x 1.280" length (6.90mm x 32.50mm). The Littelfuse substitutes measure 0.275" diameter x 1.288" length (6.99mm x 32.72mm). These dimensional variations are within standard mechanical tolerances for 3AB/3AG package format fuses and do not affect mechanical fit in standard fuse holders.