Littelfuse 0318.300H Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0318.300H is a 300 mA, 250 V AC/DC fast-blow glass cartridge fuse 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 production alternatives within the same electrical and mechanical specifications are available from the same manufacturer.

Substiute Parts

0318.300H

Littelfuse Inc.In Stock: 11450318.300H Datasheet

Current PartRFQ

0318.300HXP

Littelfuse Inc.In Stock: 9840318.300HXP Datasheet

DirectRFQ

0318.300MXP

Littelfuse Inc.In Stock: 8580318.300MXP Datasheet

Parametric EquivalentRFQ

0318.300VXP

Littelfuse Inc.In Stock: 9470318.300VXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0318.300H are determined by strict equivalence across the following critical parameters:

• Current Rating: 300 mA (exact match required)
• Voltage Rating (AC): 250 V (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)
• Breaking Capacity @ Rated Voltage: 35A (exact match required)
• Melting I²t: 0.0689 (exact match required)

All substitute parts listed below meet these criteria and are manufactured by Littelfuse Inc. within the same 318 series.

Parameter Comparison

Engineering Selection Recommendations

All three substitute parts (0318.300HXP, 0318.300MXP, 0318.300VXP) are direct functional equivalents to the obsolete 0318.300H. Selection among these active alternatives should be based on the following factors:

Product Status: The 0318.300H is obsolete. All substitute parts are in active production status, ensuring long-term availability and supply chain continuity.

Compliance & Certifications: The 0318.300H carries CSA and UL approvals. All substitute parts maintain these certifications and add CE approval, providing broader regulatory coverage for international applications.

RoHS Compliance: The 0318.300H is RoHS non-compliant. All substitute parts are ROHS3 compliant, meeting current environmental and regulatory requirements for electronic components in most jurisdictions.

Operating Temperature Range: The 0318.300H does not specify an operating temperature range. All substitute parts specify -55°C ~ 125°C, providing defined thermal performance boundaries for system design.

DC Cold Resistance: The 0318.300H specifies 1.4 Ohms; substitute parts specify 1.405 Ohms. This 0.005 Ohm variance is within normal manufacturing tolerance and does not affect functional equivalence.

Packaging: All substitute parts are supplied in bulk packaging, whereas the main part packaging is not specified. Confirm packaging requirements for procurement and inventory management.

Frequently Asked Questions (FAQ)

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

A: Yes. All three parts meet identical electrical and mechanical specifications: 300 mA current rating, 250 V AC voltage rating, fast-blow response time, 3AB/3AG package format, 35A breaking capacity, and 0.0689 melting I²t. They are direct functional equivalents.

Q: Why is the 0318.300H listed as obsolete?

A: The 0318.300H is no longer in active production. The substitute parts (0318.300HXP, 0318.300MXP, 0318.300VXP) are the current active alternatives from Littelfuse Inc. and should be used for new designs and replacements.

Q: What is the difference between 0318.300HXP, 0318.300MXP, and 0318.300VXP?

A: These parts are parametrically equivalent. The suffix designations (HXP, MXP, VXP) indicate different internal construction or packaging variants within the same electrical specification. All three meet the same functional requirements and are interchangeable for the 0318.300H application.

Q: Does the DC Cold Resistance difference (1.4 Ohms vs. 1.405 Ohms) affect compatibility?

A: No. The 0.005 Ohm variance falls within normal manufacturing tolerance for fuse components and does not impact functional performance or circuit behavior.

Q: Are the substitute parts RoHS compliant?

A: Yes. All three substitute parts (0318.300HXP, 0318.300MXP, 0318.300VXP) are ROHS3 compliant, whereas the original 0318.300H is RoHS non-compliant. This makes the substitutes suitable for applications requiring environmental compliance.

Q: What certifications do the substitute parts carry?

A: All substitute parts carry CE, CSA, and UL approvals, providing broader regulatory coverage than the original part (CSA, UL only).

Q: Can I use these fuses in applications outside the -55°C ~ 125°C temperature range?

A: The substitute parts are rated for -55°C ~ 125°C operation. Applications requiring operation outside this range require verification against specific system requirements and thermal design considerations.

Q: Is there a preferred substitute part among the three options?

A: All three parts are functionally equivalent. Selection should be based on packaging availability, supplier inventory, and procurement lead times. Consult with your component supplier for current stock status and delivery schedules.