Littelfuse 0274.500V Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0274.500V is a 500 mA, 125 V AC/DC board mount fuse designed for through-hole radial, can, vertical mounting applications. This fast-blow fuse is part of the MICRO™ 274 series and maintains active product status with full compliance to CSA, QPL, and UL standards. Alternative models become necessary when inventory constraints occur, when specific series requirements change, or when design revisions require validated substitute components with identical electrical and mechanical characteristics.

Substiute Parts

0274.500V

Littelfuse Inc.In Stock: 9900274.500V Datasheet

Current PartRFQ

0279.500V

Littelfuse Inc.In Stock: 9030279.500V Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The Littelfuse 0279.500V qualifies as a parametric equivalent to the 0274.500V based on strict alignment of all critical electrical and mechanical parameters. Substitution is valid when the following conditions are met:

Matching Parameters (Substitution Basis):

• Current Rating: 500 mA (identical)
• Voltage Rating AC: 125 V (identical)
• Voltage Rating DC: 125 V (identical)
• Response Time: Fast Blow (identical)
• Fuse Type: Board Mount (Cartridge Style Excluded) (identical)
• Mounting Type: Through Hole (identical)
• Package / Case: Radial, Can, Vertical (identical)
• Breaking Capacity @ Rated Voltage: 10 kA (identical)
• Melting I²t: 0.0716 (identical)
• Size / Dimension: 0.250" Dia x 0.350" H (6.35 mm x 8.89 mm) (identical)
• DC Cold Resistance: 0.167 Ohms (identical)
• Approval Agency: CSA, QPL, UL (identical)
• RoHS Status: ROHS3 Compliant (identical)
• REACH Status: REACH Unaffected (identical)

The 0279.500V belongs to the MICRO™ 279 series, representing a design iteration within the same product family. Both parts are active products with full regulatory compliance.

Parameter Comparison

Engineering Selection Recommendations

Both the 0274.500V and 0279.500V are active products manufactured by Littelfuse Inc. with identical electrical ratings, mechanical dimensions, and regulatory certifications. Selection between these parts should be based on:

Product Availability: Choose based on current inventory status and procurement lead times. The 0274.500V has 894 units in stock, while the 0279.500V has 840 units available.

Series Continuity: If design documentation specifies the MICRO™ 274 series, use the 0274.500V. If the MICRO™ 279 series is acceptable or preferred, the 0279.500V is a direct substitute.

Regulatory Compliance: Both parts meet CSA, QPL, and UL standards, ROHS3 compliance, and REACH requirements. No compliance advantage exists between the two options.

Operating Temperature Range: The 0279.500V provides explicit operating temperature specification (-55°C ~ 85°C), while the 0274.500V does not include this parameter in the provided data. If operating temperature range documentation is required for design validation, the 0279.500V offers this specification.

Frequently Asked Questions (FAQ)

Q: Can the 0279.500V replace the 0274.500V in existing designs?

A: Yes. The 0279.500V is a parametric equivalent with identical current rating (500 mA), voltage ratings (125 V AC/DC), response time (fast blow), mounting type (through hole), package dimensions (0.250" Dia x 0.350" H), breaking capacity (10 kA), and all regulatory certifications. Direct substitution is valid from an electrical and mechanical standpoint.

Q: What is the difference between the MICRO™ 274 and MICRO™ 279 series?

A: Both series are part of Littelfuse's board mount fuse product line. The provided data indicates these are different design iterations within the same product family. All critical electrical and mechanical parameters are identical between the 0274.500V and 0279.500V variants.

Q: Are there any compatibility concerns with PCB footprints?

A: No. Both parts share identical dimensions (0.250" Dia x 0.350" H / 6.35 mm x 8.89 mm) and mounting type (through hole radial, can, vertical). PCB footprints designed for the 0274.500V will accommodate the 0279.500V without modification.

Q: Do both parts meet the same regulatory standards?

A: Yes. Both the 0274.500V and 0279.500V carry identical approvals: CSA, QPL, and UL. Both are ROHS3 compliant and REACH unaffected.

Q: Which part should I select if both are available?

A: Selection should be based on design series requirements and inventory availability. If the design specifies MICRO™ 274 series, use the 0274.500V. If MICRO™ 279 series is acceptable, either part is suitable. Consult procurement for current stock levels and lead times.