Littelfuse 0255.500M Equivalent & Substitute Parts

Part Overview

The Littelfuse 0255.500M is a 500 mA, 125 V AC/DC board mount axial fuse from the PICO® 255 series. This component is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and component procurement. The PICO® 255 series has been superseded by newer product lines with enhanced performance characteristics and broader regulatory compliance.

Substiute Parts

0255.500M

Littelfuse Inc.In Stock: 10370255.500M Datasheet

Current PartRFQ

0251.500MXL

Littelfuse Inc.In Stock: 35610251.500MXL Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 0255.500M is determined by strict equivalence across the following electrical and mechanical parameters:

• Current Rating: 500 mA (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity: 50 A AC, 300 A DC (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Axial (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)

The Littelfuse 0251.500MXL from the PICO® II 251 series meets all electrical and mechanical substitution criteria. Physical dimensions show a minor increase in diameter (0.110" vs. 0.095"), which remains compatible with standard through-hole board mount applications designed for axial fuses in this current and voltage class.

Parameter Comparison

Engineering Selection Recommendations

The 0251.500MXL is the direct active substitute for the obsolete 0255.500M. Both components share identical electrical specifications: 500 mA current rating, 125 V AC/DC voltage rating, fast blow response, and 50 A AC / 300 A DC breaking capacity.

The 0251.500MXL offers enhanced regulatory compliance with ROHS3 certification and expanded approval agency recognition (CCC, CSA, cURus, TUV versus CSA, UL for the original part). The substitute part is actively manufactured and maintained in production inventory, ensuring long-term availability for system support and new designs.

Physical dimensions show a minor diameter increase (0.110" versus 0.095"), with length remaining constant at 0.280". This dimensional change is within standard tolerance for through-hole axial fuse mounting and does not affect electrical performance or circuit board compatibility for applications designed to accommodate standard axial fuse packages in this current class.

Frequently Asked Questions (FAQ)

Q: Can the 0251.500MXL be used as a direct replacement for the 0255.500M in existing designs?

A: Yes. Both parts share identical electrical ratings (500 mA, 125 V AC/DC, fast blow response) and breaking capacity specifications. The minor diameter increase (0.110" versus 0.095") is compatible with standard through-hole board mount applications for axial fuses in this current and voltage class.

Q: What is the difference in physical size between these two parts?

A: The 0251.500MXL has a diameter of 0.110" (2.80mm) compared to 0.095" (2.41mm) for the 0255.500M. The length remains identical at 0.280" (7.11mm) for both parts. The increased diameter does not affect electrical performance or standard board mount compatibility.

Q: Why is the 0255.500M listed as obsolete?

A: The 0255.500M belongs to the PICO® 255 series, which has been superseded by the PICO® II 251 series. Littelfuse has transitioned production to the newer series, which offers improved regulatory compliance and broader certification coverage.

Q: Are there any compliance differences between the two parts?

A: The 0251.500MXL is ROHS3 compliant and carries expanded regulatory approvals (CCC, CSA, cURus, TUV). The 0255.500M is RoHS non-compliant and carries CSA and UL approvals. For new designs or systems requiring RoHS compliance, the 0251.500MXL is the appropriate selection.

Q: Is the 0251.500MXL available in production quantities?

A: Yes. The 0251.500MXL is an active product with current manufacturing status and documented inventory availability, ensuring reliable procurement for both replacement and new design applications.