Littelfuse 0279.800V Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0279.800V is an 800 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™ 279 series and carries active product status with full compliance to CSA, QPL, and UL approval agencies. Equivalent and substitute parts are identified when component availability, supply chain constraints, or design flexibility require alternative sourcing while maintaining identical electrical and mechanical performance specifications.

Substiute Parts

0279.800V

Littelfuse Inc.In Stock: 7810279.800V Datasheet

Current PartRFQ

0273.800V

Littelfuse Inc.In Stock: 7430273.800V Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The Littelfuse 0273.800V qualifies as a parametric equivalent to the 0279.800V based on identical electrical and mechanical specifications. Substitution is valid when the following criteria are met:

• Current rating: 800 mA (exact match)
• Voltage rating: 125 V AC and 125 V DC (exact match)
• Response time: Fast Blow (exact match)
• Mounting configuration: Through Hole, Radial, Can, Vertical (exact match)
• Breaking capacity: 10 kA @ rated voltage (exact match)
• Melting I²t: 0.113 (exact match)
• Physical dimensions: 0.250" Dia x 0.350" H (exact match)
• DC cold resistance: 0.271 Ohms (exact match)
• Operating temperature range: -55°C to 85°C (exact match)
• Regulatory compliance: CSA, QPL, UL (exact match)
• RoHS compliance: ROHS3 Compliant (exact match)

The primary difference between these parts is the series designation: MICRO™ 279 versus MICRO™ 273. Both are manufactured by Littelfuse Inc. and maintain identical performance characteristics across all specified parameters.

Parameter Comparison

Engineering Selection Recommendations

Both the 0279.800V and 0273.800V maintain active product status with identical regulatory certifications (CSA, QPL, UL) and full RoHS3 compliance. Selection between these parts is determined by availability and supply chain requirements rather than electrical or mechanical performance differences. Both parts satisfy identical circuit protection requirements for 800 mA, 125 V AC/DC applications with fast-blow response characteristics. The MICRO™ 273 series (0273.800V) serves as a direct functional replacement when the MICRO™ 279 series (0279.800V) is unavailable.

Frequently Asked Questions (FAQ)

Q: Can the 0273.800V be used as a direct replacement for the 0279.800V in existing designs?

A: Yes. The 0273.800V is electrically and mechanically identical to the 0279.800V across all specified parameters, including current rating, voltage rating, response time, physical dimensions, and regulatory approvals. No circuit modifications are required.

Q: Are there any differences in mounting or PCB layout considerations between these parts?

A: No. Both parts share identical mounting specifications: through-hole, radial, can, vertical configuration with dimensions of 0.250" Dia x 0.350" H (6.35 mm x 8.89 mm). PCB footprints and mounting hole patterns are identical.

Q: Do both parts carry the same regulatory approvals?

A: Yes. Both the 0279.800V and 0273.800V carry CSA, QPL, and UL approvals and are ROHS3 compliant. Regulatory compliance is identical.

Q: What is the difference between the MICRO™ 279 and MICRO™ 273 series?

A: The series designation reflects internal Littelfuse product line organization. From an engineering standpoint, the 800 mA, 125 V AC/DC specifications are identical between both series. The series difference does not affect electrical performance, breaking capacity, or thermal characteristics.

Q: Are there any temperature or environmental performance differences?

A: No. Both parts operate across the identical temperature range of -55°C to 85°C with identical DC cold resistance of 0.271 Ohms and melting I²t of 0.113.