MS 2 Fuse Board Mount Equivalent & Substitute Parts

Part Overview

The MS 2 is a 2 A, 125 V AC/DC board mount axial fuse manufactured by Bel Fuse Inc. with slow blow response characteristics. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement. The MS 2 serves as a protective device in through-hole applications requiring 2 ampere current limiting at 125 volt ratings across both AC and DC circuits.

Substiute Parts

MS 2

Bel Fuse Inc.In Stock: 1106MS 2 Datasheet

Current PartRFQ

0034.6071

SCHURTER Inc.In Stock: 15480034.6071 Datasheet

DirectRFQ

0473002.MRT1L

Littelfuse Inc.In Stock: 12170473002.MRT1L Datasheet

DirectRFQ

0473002.YRT1L

Littelfuse Inc.In Stock: 254850473002.YRT1L Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MS 2 are identified based on strict electrical and mechanical parameter alignment. The primary substitution criteria are:

• Current Rating: 2 A (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (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 ~ 125°C minimum (equal or broader range acceptable)

Two active substitute parts meet these criteria and are sourced from Littelfuse Inc., the PICO® II 473 series. The part 0034.6071 from SCHURTER Inc. does not qualify as a direct substitute due to differing current rating (500 mA vs. 2 A), voltage rating (250 V vs. 125 V), response time (Fast Blow vs. Slow Blow), and package configuration (Radial vs. Axial).

Parameter Comparison

Engineering Selection Recommendations

Both 0473002.MRT1L and 0473002.YRT1L from Littelfuse Inc. are active product status alternatives to the obsolete MS 2. These parts maintain identical electrical specifications across current rating, voltage ratings, and response time characteristics. Both are ROHS3 compliant and carry CSA and UR certifications, providing regulatory alignment for modern applications.

The dimensional difference between the MS 2 (0.125" diameter) and the Littelfuse substitutes (0.135" diameter) is minimal and within typical PCB design tolerances for through-hole axial components. The lower DC cold resistance of the Littelfuse parts (0.0712 Ohms vs. 0.105 Ohms) represents improved electrical performance characteristics.

Selection between 0473002.MRT1L and 0473002.YRT1L should be based on supply chain availability and REACH compliance requirements. The 0473002.YRT1L carries REACH Affected status with significantly higher inventory availability (25,387 pieces vs. 1,124 pieces), while 0473002.MRT1L maintains REACH Unaffected status.

Frequently Asked Questions (FAQ)

Q: Can the SCHURTER part 0034.6071 be used as a substitute for the MS 2?

A: No. The 0034.6071 differs in multiple critical parameters: current rating (500 mA vs. 2 A), voltage rating (250 V vs. 125 V), response time (Fast Blow vs. Slow Blow), and package configuration (Radial vs. Axial). These differences make it unsuitable for direct substitution.

Q: What is the difference between 0473002.MRT1L and 0473002.YRT1L?

A: Both parts are electrically and mechanically identical. The primary differences are REACH compliance status (MRT1L is REACH Unaffected; YRT1L is REACH Affected) and inventory availability (MRT1L has 1,124 pieces; YRT1L has 25,387 pieces in stock).

Q: Will the slightly larger diameter of the Littelfuse substitutes affect PCB compatibility?

A: The diameter increase from 0.125" to 0.135" is 0.010" (0.25 mm), which is within standard PCB design tolerances for through-hole axial components. No design modification is required.

Q: Are the Littelfuse substitutes certified to the same standards as the MS 2?

A: Both Littelfuse parts carry CSA and UR certifications. The MS 2 also includes CE and cURus certifications. The Littelfuse parts add PSE certification. All parts meet the core safety and regulatory requirements for board mount fuse applications.

Q: How does the lower DC cold resistance of the Littelfuse parts affect circuit performance?

A: The lower DC cold resistance (0.0712 Ohms vs. 0.105 Ohms) in the Littelfuse substitutes represents improved electrical characteristics, resulting in lower voltage drop across the fuse element during normal operation. This is a performance advantage with no negative impact on circuit compatibility.