Littelfuse 0278.005V Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0278.005V is a 5 mA, 125 V AC/DC board mount fuse in the MICRO™ 278 series, designed for through-hole radial mounting applications. This fast-blow fuse provides circuit protection in compact form factor with a breaking capacity of 10 kA at rated voltage. The part is actively manufactured and maintains full compliance with RoHS3, REACH, and major approval agencies including UL, CSA, and QPL. Substitute parts are identified when equivalent electrical and mechanical parameters are maintained across the same product category.

Substiute Parts

0278.005V

Littelfuse Inc.In Stock: 10850278.005V Datasheet

Current PartRFQ

0272.005V

Littelfuse Inc.In Stock: 8730272.005V Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The Littelfuse 0272.005V qualifies as a parametric equivalent to the 0278.005V based on identical electrical and mechanical specifications. Both parts share the following critical substitution parameters:

• Current Rating: 5 mA
• Voltage Rating: 125 V AC / 125 V DC
• Response Time: Fast Blow
• Mounting Type: Through Hole
• Package / Case: Radial, Can, Vertical
• Breaking Capacity: 10 kA
• Operating Temperature Range: -55°C ~ 125°C
• Physical Dimensions: 0.235" Dia x 0.287" H (5.97mm x 7.30mm)
• DC Cold Resistance: 280 Ohms

Both parts are manufactured by Littelfuse Inc., maintain active product status, and carry identical compliance certifications (UL, CSA, QPL, RoHS3, REACH Unaffected).

Parameter Comparison

Engineering Selection Recommendations

Both the 0278.005V and 0272.005V are suitable for direct substitution in applications requiring 5 mA, 125 V AC/DC board mount fuses with fast-blow response characteristics. Selection between these parts may be based on availability and inventory status. The 0278.005V (MICRO™ 278 series) currently maintains 1036 pieces in stock, while the 0272.005V (MICRO™ 272 series) maintains 819 pieces in stock. Both parts carry identical electrical performance specifications, mechanical dimensions, and regulatory compliance certifications, ensuring functional equivalence in circuit protection applications.

Frequently Asked Questions (FAQ)

Q: Can the 0272.005V replace the 0278.005V in existing designs?

A: Yes. Both parts are parametric equivalents with identical current ratings, voltage ratings, response times, physical dimensions, and breaking capacity. The primary difference is the series designation (MICRO™ 272 versus MICRO™ 278). No circuit redesign is required.

Q: Are the physical dimensions identical between these two fuses?

A: Yes. Both parts measure 0.235" diameter by 0.287" height (5.97mm x 7.30mm) and use identical radial, can, vertical package configuration. PCB footprints and mounting hole spacing are compatible.

Q: Do both parts meet the same regulatory standards?

A: Yes. Both the 0278.005V and 0272.005V carry identical approvals from UL, CSA, and QPL. Both are RoHS3 compliant and REACH unaffected.

Q: What is the operating temperature range for these fuses?

A: Both parts operate across -55°C to 125°C, providing consistent thermal performance across industrial and commercial temperature environments.

Q: Is there a difference in response time between these substitutes?

A: No. Both parts are fast-blow fuses with identical melting I²t values of 8.1E-09, ensuring equivalent protection response in overcurrent conditions.