Bel Fuse Inc. 3AP 8 Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 3AP 8 is an 8 A, 250 V AC/DC fast-blow glass cartridge fuse in 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. The fuse provides overcurrent protection in through-hole applications with a 200 A breaking capacity and operates across -55°C to 125°C temperature range.

Substiute Parts

3AP 8

Bel Fuse Inc.In Stock: 8953AP 8 Datasheet

Current PartRFQ

0318008.HXP

LittelfuseIn Stock: 8630318008.HXP Datasheet

DirectRFQ

0318008.MXP

Littelfuse Inc.In Stock: 27200318008.MXP Datasheet

DirectRFQ

0318008.VXP

Littelfuse Inc.In Stock: 7750318008.VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3AP 8 is determined by strict equivalence across the following electrical and mechanical parameters:

• Current Rating: 8 A (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Response Time: Fast Blow (exact match required)
• Package Format: 3AB, 3AG, 1/4" x 1-1/4" axial (exact match required)
• Mounting Type: Through Hole (exact match required)
• Breaking Capacity: 200 A (exact match required)

All substitute parts listed below meet these criteria. Littelfuse Inc. series 318 fuses (0318008.HXP, 0318008.MXP, 0318008.VXP) are direct functional equivalents manufactured to the same electrical and mechanical specifications as the obsolete Bel Fuse 3AP 8.

Parameter Comparison

Engineering Selection Recommendations

All three Littelfuse 318 series fuses (0318008.HXP, 0318008.MXP, 0318008.VXP) are functionally equivalent to the obsolete Bel Fuse 3AP 8 across all critical electrical and mechanical parameters. Selection among these three substitutes should be based on:

Product Availability: Littelfuse 0318008.MXP offers the highest inventory level (2612 pcs), followed by 0318008.VXP (706 pcs) and 0318008.HXP (797 pcs).

Compliance Status: All three Littelfuse substitutes are ROHS3 compliant and carry expanded regulatory approvals (CE, CSA, KC, PSE, UL) compared to the original Bel Fuse part. The original 3AP 8 is RoHS non-compliant and obsolete.

Physical Dimensions: Littelfuse substitutes exhibit minor dimensional variations (0.275" Dia x 1.288" L versus 0.272" Dia x 1.280" L) within standard manufacturing tolerances for 3AB/3AG cartridge fuses. These variations do not affect mechanical fit in standard through-hole fuse holders.

Electrical Performance: DC cold resistance and melting I²t values are within acceptable engineering tolerances for fast-blow glass cartridge fuses of this rating class.

Frequently Asked Questions (FAQ)

Q: Can Littelfuse 0318008.HXP, 0318008.MXP, and 0318008.VXP be used interchangeably as substitutes for the Bel Fuse 3AP 8?

A: Yes. All three Littelfuse parts meet identical electrical specifications (8 A, 250 V AC, fast-blow response) and mechanical requirements (3AB/3AG package, through-hole mounting, 1/4" x 1-1/4" form factor). Selection depends on availability and compliance requirements.

Q: What is the difference between the three Littelfuse substitute part numbers?

A: The part numbers 0318008.HXP, 0318008.MXP, and 0318008.VXP represent different packaging or distribution variants within the Littelfuse 318 series. All three are electrically and mechanically identical and carry the same electrical ratings and certifications.

Q: Will the Littelfuse substitutes fit in existing fuse holders designed for the Bel Fuse 3AP 8?

A: Yes. The 3AB/3AG package format and through-hole mounting type are standardized. Minor dimensional variations (approximately 0.003" in diameter and 0.008" in length) fall within standard manufacturing tolerances and do not affect fit in standard fuse holders.

Q: Are there any compliance or regulatory differences between the original Bel Fuse 3AP 8 and the Littelfuse substitutes?

A: The original Bel Fuse 3AP 8 is RoHS non-compliant and obsolete. All Littelfuse substitutes are ROHS3 compliant and carry active product status with expanded regulatory approvals (KC added to the original CE, CSA, PSE, UL certifications).

Q: How do the melting I²t values differ, and does this affect substitution?

A: The Bel Fuse 3AP 8 has a melting I²t of 184, while Littelfuse substitutes have 166. Both values are within the acceptable range for 8 A fast-blow cartridge fuses and do not prevent direct substitution in standard overcurrent protection applications.