MS 2.5 Equivalent & Substitute Parts Reference

Part Overview

The MS 2.5 is a 2.5 A, 125 V AC/DC board mount axial fuse manufactured by Bel Fuse Inc. with slow blow response characteristics. This part is classified as obsolete, making equivalent and substitute components necessary for ongoing system support and new design implementations. The MS 2.5 series provides through-hole axial mounting with a compact 0.125" diameter and 0.280" length profile, suitable for applications requiring reliable overcurrent protection in low-voltage circuits.

Substiute Parts

MS 2.5

Bel Fuse Inc.In Stock: 713MS 2.5 Datasheet

Current PartRFQ

0034.6817

SCHURTER Inc.In Stock: 9590034.6817 Datasheet

DirectRFQ

047302.5MRT1L

Littelfuse Inc.In Stock: 4766047302.5MRT1L Datasheet

DirectRFQ

047302.5YRT1L

Littelfuse Inc.In Stock: 1077047302.5YRT1L Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MS 2.5 is determined by the following critical parameters:

• Current Rating: 2.5 A (exact match required)
• Voltage Rating - AC: 125 V (exact match required)
• Voltage Rating - DC: 125 V (exact match required)
• Response Time: Slow Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Axial (exact match required)
• Operating Temperature Range: -55°C to 125°C (minimum requirement)

The substitute parts identified below meet all critical electrical and mechanical parameters. Parts 047302.5MRT1L and 047302.5YRT1L are direct equivalents from Littelfuse Inc., differing only in packaging format (Cut Tape vs. Tape & Reel). Part 0034.6817 from SCHURTER Inc. does not meet substitution criteria due to lower current rating (1.6 A vs. 2.5 A) and different package geometry (Radial, Can, Vertical vs. Axial).

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalents (Recommended for MS 2.5 Replacement):

047302.5MRT1L and 047302.5YRT1L from Littelfuse Inc. are functionally equivalent to the MS 2.5. Both parts maintain identical electrical specifications: 2.5 A current rating, 125 V AC/DC voltage rating, slow blow response, and through-hole axial mounting. The Littelfuse parts are active products with current manufacturing support and ROHS3 compliance, providing superior long-term availability compared to the obsolete MS 2.5. Selection between these two Littelfuse variants depends on packaging requirements: 047302.5MRT1L is supplied in Cut Tape format, while 047302.5YRT1L is supplied in Tape & Reel format.

Non-Equivalent Alternative:

0034.6817 from SCHURTER Inc. does not qualify as a substitute for the MS 2.5 due to current rating mismatch (1.6 A vs. 2.5 A) and incompatible package geometry (Radial, Can, Vertical vs. Axial). This part cannot be used as a direct replacement in circuits designed for 2.5 A protection.

Frequently Asked Questions (FAQ)

Q: Can 0034.6817 be used as a substitute for MS 2.5?

A: No. The 0034.6817 has a current rating of 1.6 A, which is lower than the MS 2.5's 2.5 A rating. Additionally, its package geometry (Radial, Can, Vertical) is incompatible with the axial through-hole mounting of the MS 2.5. This part cannot provide equivalent protection in circuits designed for the MS 2.5.

Q: What is the difference between 047302.5MRT1L and 047302.5YRT1L?

A: Both parts are electrically and mechanically identical. The difference is packaging: 047302.5MRT1L is supplied in Cut Tape (CT) format, while 047302.5YRT1L is supplied in Tape & Reel (TR) format. Selection depends on your procurement and assembly process requirements.

Q: Are the Littelfuse equivalents physically compatible with the MS 2.5 footprint?

A: The Littelfuse parts have slightly larger diameter (0.135" vs. 0.125") and identical length (0.280"). Both maintain through-hole axial mounting and are compatible with standard PCB layouts designed for the MS 2.5, though minor dimensional variation should be verified for space-constrained applications.

Q: What certifications do the substitute parts carry?

A: 047302.5MRT1L and 047302.5YRT1L carry CSA, PSE, and UR approvals. The MS 2.5 carries CE, CSA, and cURus approvals. Verify that the substitute part's certification portfolio meets your application's regulatory requirements.

Q: Why is the MS 2.5 obsolete?

A: The MS 2.5 is classified as obsolete by Bel Fuse Inc. The Littelfuse PICO® II 473 series (047302.5MRT1L and 047302.5YRT1L) represents the current active equivalent technology for this protection class.