Littelfuse 0251.500M Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0251.500M is a 500 mA, 125 V AC/DC board mount axial fuse in the PICO® II 251 series. This component is classified as obsolete, making identification of active equivalent parts essential for ongoing design support and procurement. The part features fast-blow response characteristics and is approved by CCC, CSA, cURus, and TUV agencies. Due to its obsolete status, active substitute parts with identical electrical and mechanical specifications are available to ensure design continuity.

Substiute Parts

0251.500M

Littelfuse Inc.In Stock: 12340251.500M Datasheet

Current PartRFQ

0251.500MXL

Littelfuse Inc.In Stock: 35610251.500MXL Datasheet

Parametric EquivalentRFQ

0251.500VXL

Littelfuse Inc.In Stock: 9930251.500VXL Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 0251.500M is determined by strict equivalence across all critical electrical and mechanical parameters. The substitute parts 0251.500MXL and 0251.500VXL maintain identical specifications in the following key areas:

• Current Rating: 500 mA
• Voltage Rating: 125 V AC / 125 V DC
• Response Time: Fast Blow
• Mounting Type: Through Hole
• Package / Case: Axial
• Physical Dimensions: 0.110" Dia x 0.280" L (2.80mm x 7.11mm)
• Breaking Capacity: 50A AC, 300A DC
• DC Cold Resistance: 0.302 Ohms
• Melting I²t: 0.0598
• Approval Agencies: CCC, CSA, cURus, TUV
• Operating Temperature Range: -55°C ~ 125°C

Both substitute parts are active products with improved RoHS3 compliance status, distinguishing them from the obsolete main part.

Parameter Comparison

Engineering Selection Recommendations

Both 0251.500MXL and 0251.500VXL are direct functional equivalents to the 0251.500M. The primary distinction is product status and regulatory compliance. The 0251.500M is obsolete, while both substitute parts are active products with ROHS3 compliance and REACH unaffected status. For new designs or ongoing procurement, either 0251.500MXL or 0251.500VXL may be selected based on packaging availability and inventory requirements. Both parts maintain identical electrical performance, mechanical fit, and agency approvals required for the application.

Frequently Asked Questions (FAQ)

Q: Can 0251.500MXL and 0251.500VXL be used interchangeably with 0251.500M?

A: Yes. Both substitute parts are parametric equivalents with identical electrical ratings (500 mA, 125 V AC/DC), response characteristics (fast blow), physical dimensions (0.110" Dia x 0.280" L), and agency approvals (CCC, CSA, cURus, TUV). They are direct replacements for through-hole axial board mount applications.

Q: What is the difference between 0251.500MXL and 0251.500VXL?

A: Both parts are electrically and mechanically identical. The difference lies in packaging designation (MXL vs. VXL suffix). Selection between them depends on procurement and inventory management preferences. Both are active products with ROHS3 compliance.

Q: Why is the 0251.500M listed as obsolete?

A: The 0251.500M has been superseded by active equivalent parts. Littelfuse continues to support the PICO® II 251 series through the 0251.500MXL and 0251.500VXL variants, which offer improved regulatory compliance (ROHS3).

Q: Are there any dimensional or mounting differences between these parts?

A: No. All three parts share identical dimensions (0.110" Dia x 0.280" L / 2.80mm x 7.11mm) and through-hole axial mounting configuration. Direct PCB footprint compatibility is maintained.

Q: Do the substitute parts have the same breaking capacity?

A: Yes. All parts maintain 50A AC and 300A DC breaking capacity at rated voltage, with identical melting I²t values of 0.0598 and DC cold resistance of 0.302 Ohms.