MS 7TR Board Mount Fuse - Equivalent & Substitute Parts

Part Overview

The MS 7TR is a 7A 125VAC/VDC board mount axial fuse manufactured by Bel Fuse Inc., designed for through-hole PCB applications. This part carries an obsolete product status, making identification of active equivalent alternatives essential for ongoing production and maintenance applications. The MS 7TR specifications define a slow-blow fuse with 50A AC and 300A DC breaking capacity, suitable for circuit protection in industrial and commercial electronics requiring moderate current ratings and dual voltage operation.

Substiute Parts

MS 7TR

Bel Fuse Inc.In Stock: 1100MS 7TR Datasheet

Current PartRFQ

MRF 4-BULK

Bel Fuse Inc.In Stock: 1104MRF 4-BULK Datasheet

DirectRFQ

0473007.MRT1L

Littelfuse Inc.In Stock: 14840473007.MRT1L Datasheet

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0473007.YRT1L

Littelfuse Inc.In Stock: 749120473007.YRT1L Datasheet

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0473007.MAT1L

Littelfuse Inc.In Stock: 11680473007.MAT1L Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MS 7TR is determined by the following critical parameters: current rating (7A), voltage ratings (125VAC/125VDC), response time (slow blow), mounting type (through hole), and package configuration (axial). Parts meeting these specifications are classified as direct equivalents. The Littelfuse PICO® II 473 series parts (0473007.MRT1L, 0473007.YRT1L, 0473007.MAT1L) satisfy all primary electrical and mechanical requirements, differing only in packaging format (Cut Tape vs. bulk) and minor dimensional tolerances within acceptable engineering limits. The MRF 4-BULK part from Bel Fuse Inc. does not qualify as a direct substitute due to reduced current rating (4A vs. 7A), increased voltage rating (250VAC vs. 125VAC), and different package configuration (radial vs. axial).

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse PICO® II 473 series (0473007.MRT1L, 0473007.YRT1L, 0473007.MAT1L) represents the primary substitute option for the obsolete MS 7TR. All three variants maintain electrical equivalence with identical current, voltage, and response time specifications. Selection between these three parts depends on packaging requirements: 0473007.MRT1L and 0473007.MAT1L are supplied in Cut Tape format, while 0473007.YRT1L offers the highest inventory availability (74,878 pcs). The Littelfuse alternatives carry active product status and ROHS3 compliance, supporting long-term supply chain continuity. Minor dimensional variations (0.135" vs. 0.125" diameter) and reduced DC cold resistance (0.0092 vs. 0.011 Ohms) fall within acceptable engineering tolerances for board mount fuse applications. CSA and UR certifications on Littelfuse parts satisfy regulatory requirements for most industrial applications, though designs requiring cURus certification should be evaluated against specific application standards.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse PICO® II 473 series parts directly replace the MS 7TR without PCB modification?

A: Yes. The 0473007.MRT1L, 0473007.YRT1L, and 0473007.MAT1L parts are mechanically and electrically compatible with the MS 7TR. Axial package configuration and through-hole mounting remain identical. Minor diameter tolerance differences (3.43mm vs. 3.18mm) are within standard PCB pad design margins.

Q: What is the difference between 0473007.MRT1L, 0473007.YRT1L, and 0473007.MAT1L?

A: These three parts are electrically and mechanically identical. The designations reflect packaging format variations within the Cut Tape supply chain. Selection should prioritize inventory availability and procurement lead time requirements.

Q: Is the MRF 4-BULK a suitable substitute for the MS 7TR?

A: No. The MRF 4-BULK operates at 4A current rating and 250VAC voltage, differing from the MS 7TR specifications of 7A and 125VAC. Additionally, the MRF 4-BULK uses radial package configuration rather than axial, requiring PCB redesign. This part is not electrically or mechanically compatible.

Q: What certifications should I verify for my specific application?

A: The MS 7TR carries CE, CSA, and cURus approvals. Littelfuse substitutes carry CSA and UR certifications. Verify that UR certification meets your application requirements if cURus was previously specified. Consult your design standards and regional regulatory requirements.

Q: Are there supply chain advantages to using the Littelfuse alternatives?

A: Yes. The Littelfuse PICO® II 473 series parts carry active product status with substantial inventory levels (1,400 to 74,878 pcs available), compared to the obsolete MS 7TR status. This ensures long-term availability and supports production continuity.