3AP 10-R Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The 3AP 10-R is a 10 A, 250 V AC/DC glass cartridge fuse manufactured by Bel Fuse Inc. in the 3AB/3AG form factor with fast-blow response characteristics. This component is classified as obsolete, necessitating identification of active equivalent alternatives for ongoing system support and procurement. Substitute parts must maintain identical electrical ratings, mechanical dimensions, and performance characteristics to ensure direct interchangeability in through-hole applications.

Substiute Parts

3AP 10-R

Bel Fuse Inc.In Stock: 9123AP 10-R Datasheet

Current PartRFQ

0318010.HXP

Littelfuse Inc.In Stock: 115720318010.HXP Datasheet

DirectRFQ

0318010.MXP

Littelfuse Inc.In Stock: 12360318010.MXP Datasheet

DirectRFQ

0318010.VXP

Littelfuse Inc.In Stock: 9420318010.VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3AP 10-R is determined by strict equivalence across the following parameters:

• Current Rating: 10 A (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)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Breaking Capacity: 200 A (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)

All three substitute parts—0318010.HXP, 0318010.MXP, and 0318010.VXP—manufactured by Littelfuse Inc. meet these criteria and are classified as active products with current availability.

Parameter Comparison

Engineering Selection Recommendations

All three Littelfuse 318 series substitutes (0318010.HXP, 0318010.MXP, 0318010.VXP) are direct functional equivalents to the obsolete 3AP 10-R. Selection among these three variants should be based on procurement availability and inventory status:

• 0318010.HXP: 11,500 pcs in stock (highest availability)
• 0318010.MXP: 1,211 pcs in stock
• 0318010.VXP: 881 pcs in stock

All three parts carry expanded regulatory approvals (CE, CSA, KC, PSE, UL) compared to the original part, providing enhanced compliance coverage. Dimensional tolerances between the original and substitute parts are within acceptable mechanical clearance limits for standard through-hole fuse holders. The minor variations in melting I²t (298 vs. 316) and DC cold resistance (0.0093 vs. 0.009 Ohms) remain within the performance envelope for this fuse category and do not affect functional interchangeability.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 0318010 series parts be used as direct replacements for the 3AP 10-R?

A: Yes. All three Littelfuse variants (0318010.HXP, 0318010.MXP, 0318010.VXP) meet the electrical and mechanical specifications required for direct substitution. Current rating, voltage rating, package dimensions, response time, and breaking capacity are identical.

Q: What is the difference between 0318010.HXP, 0318010.MXP, and 0318010.VXP?

A: These three part numbers represent the same electrical and mechanical specification within the Littelfuse 318 series. The suffix designations (.HXP, .MXP, .VXP) indicate internal manufacturing or packaging variants. All three are functionally equivalent for circuit protection applications.

Q: Are there dimensional differences between the 3AP 10-R and the Littelfuse substitutes?

A: Minor dimensional variations exist. The 3AP 10-R measures 0.272" Dia x 1.280" L, while the Littelfuse parts measure 0.275" Dia x 1.288" L. These differences are within standard mechanical tolerances for 3AB/3AG form factor fuses and do not prevent installation in standard through-hole fuse holders.

Q: Do the substitute parts have the same regulatory approvals?

A: The Littelfuse substitutes carry expanded approvals (CE, CSA, KC, PSE, UL) compared to the original 3AP 10-R (CE, CSA, cULus). This provides broader compliance coverage for international applications.

Q: What is the significance of the melting I²t difference?

A: The original 3AP 10-R has a melting I²t of 316, while the Littelfuse substitutes have 298. Both values fall within the fast-blow fuse category and maintain the same 10 A current rating and 250 V voltage rating. This difference does not affect functional interchangeability in standard circuit protection applications.

Q: Which substitute part should I select for new designs?

A: For new designs, any of the three Littelfuse variants is acceptable. Selection should prioritize availability: 0318010.HXP offers the highest stock level (11,500 pcs), making it the preferred choice for volume procurement.