Equivalent & Substitute Parts for Littelfuse 0272.050V Board Mount Fuse

Part Overview

The Littelfuse 0272.050V is a 50 mA, 125 V AC/DC board mount fuse in the MICRO™ 272 series, designed for through-hole radial mounting applications. This fast-blow fuse is actively manufactured and widely stocked. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and application-specific voltage or thermal requirements.

Substiute Parts

0272.050V

Littelfuse Inc.In Stock: 23750272.050V Datasheet

Current PartRFQ

30300500421

Littelfuse Inc.In Stock: 116830300500421 Datasheet

MFR RecommendedRFQ

0278.050V

LittelfuseIn Stock: 22560278.050V Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following criteria:

Parametric Equivalent (Full Compatibility): Parts matching all critical electrical parameters—current rating (50 mA), AC voltage (125 V), DC voltage (125 V), response time (Fast Blow), mounting type (Through Hole), and package style (Radial, Can, Vertical)—are classified as parametric equivalents. These parts are interchangeable without circuit modification.

Manufacturer Recommended Substitute (Conditional Compatibility): Parts meeting the current rating (50 mA) and AC voltage (125 V) but with reduced DC voltage rating (63 V instead of 125 V) are listed as manufacturer-recommended substitutes. These parts are suitable only for applications where the DC voltage requirement does not exceed 63 V.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: The 0278.050V (MICRO™ 278 series) is the parametric equivalent and provides identical electrical and thermal performance. Both parts carry CSA, QPL, and UL certifications and operate across the full temperature range of -55°C to 125°C. Selection between 0272.050V and 0278.050V depends on series availability and procurement lead times.

For DC Voltage-Constrained Applications: The 30300500421 (TR3® 303 series) is suitable only when the circuit DC voltage does not exceed 63 V. This part carries CSA and UL certifications but operates within a narrower temperature range (-25°C to 70°C) and has a lower breaking capacity (50 A versus 10 kA). Use this substitute only when DC voltage requirements are confirmed below 63 V.

Compliance Considerations: All three parts are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99. Selection should account for the specific approval agency requirements of the end application.

Frequently Asked Questions (FAQ)

Q: Can the 30300500421 be used as a direct replacement for the 0272.050V?

A: No. The 30300500421 has a reduced DC voltage rating of 63 V compared to the 0272.050V's 125 V DC rating. It is suitable only for applications where the DC voltage does not exceed 63 V. Additionally, its operating temperature range is limited to -25°C to 70°C, which may not be acceptable for applications requiring the full -55°C to 125°C range.

Q: What is the difference between the 0272.050V and 0278.050V?

A: Both parts are parametric equivalents with identical electrical specifications: 50 mA current rating, 125 V AC/DC voltage rating, fast-blow response, 10 kA breaking capacity, and -55°C to 125°C operating temperature. They differ only in series designation (MICRO™ 272 versus MICRO™ 278) and are interchangeable for all applications.

Q: Are all substitute parts RoHS compliant?

A: Yes. The 0272.050V, 0278.050V, and 30300500421 are all ROHS3 compliant and REACH unaffected.

Q: What certifications apply to each part?

A: The 0272.050V and 0278.050V carry CSA, QPL, and UL certifications. The 30300500421 carries CSA and UL certifications. Verify that the required certifications match your application's regulatory requirements before selection.

Q: Can these fuses be used in high-temperature applications?

A: The 0272.050V and 0278.050V support operation up to 125°C. The 30300500421 is limited to 70°C maximum. For applications requiring sustained operation above 70°C, use the 0272.050V or 0278.050V.