MS 375 Equivalent & Substitute Parts Reference

Part Overview

The MS 375 is a 375 mA board mount axial fuse rated for 125 V AC/DC operation, manufactured by Bel Fuse Inc. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement. The MS 375 maintains slow blow response characteristics suitable for applications requiring transient current protection without nuisance trips.

Substiute Parts

MS 375

Bel Fuse Inc.In Stock: 940MS 375 Datasheet

Current PartRFQ

0473.375MRT1L

Littelfuse Inc.In Stock: 154950473.375MRT1L Datasheet

DirectRFQ

0473.375YRT1L

Littelfuse Inc.In Stock: 12050473.375YRT1L Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MS 375 are qualified based on the following electrical and mechanical parameters:

• Current Rating: 375 mA (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)
• Fuse Type: Board Mount, Axial configuration (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)

The substitute parts 0473.375MRT1L and 0473.375YRT1L, both from Littelfuse Inc. PICO® II 473 series, meet all critical electrical parameters. These parts differ from the original MS 375 in packaging format (Cut Tape and Tape & Reel respectively) and minor dimensional variations within acceptable mechanical tolerances for board mount applications.

Parameter Comparison

Engineering Selection Recommendations

The MS 375 is obsolete; therefore, substitution with active production parts is required for new procurement and design continuity.

Both Littelfuse PICO® II 473 series substitutes (0473.375MRT1L and 0473.375YRT1L) are active production components with current inventory availability. Both parts maintain CSA and UR certifications, meeting regulatory requirements for the application.

Selection between the two Littelfuse substitutes depends on packaging requirements:

• 0473.375MRT1L: Cut Tape (CT) packaging, 15,400 units in stock
• 0473.375YRT1L: Tape & Reel (TR) packaging, 1,120 units in stock

Both substitutes are ROHS3 compliant and REACH unaffected, providing environmental compliance advantages over the obsolete MS 375.

Frequently Asked Questions (FAQ)

Q: Can 0473.375MRT1L and 0473.375YRT1L be used interchangeably with MS 375?

A: Yes. Both Littelfuse parts meet all critical electrical parameters: 375 mA current rating, 125 V AC/DC voltage rating, slow blow response, through hole mounting, and axial package configuration. The difference is packaging format (Cut Tape vs. Tape & Reel), not electrical performance.

Q: What is the difference between the two Littelfuse substitutes?

A: 0473.375MRT1L and 0473.375YRT1L are electrically identical. The difference is packaging: MRT1L uses Cut Tape format suitable for manual or small-scale assembly, while YRT1L uses Tape & Reel format for automated pick-and-place equipment.

Q: Are there dimensional differences between MS 375 and the Littelfuse substitutes?

A: Minor dimensional variations exist. MS 375 is 0.125" diameter × 0.280" length; Littelfuse parts are 0.135" diameter × 0.280" length. These differences are within acceptable mechanical tolerances for board mount through-hole applications and do not affect electrical performance or board compatibility.

Q: Do the substitutes have the same breaking capacity as MS 375?

A: The Littelfuse substitutes specify 50A breaking capacity at rated voltage. The MS 375 specifies 50A AC and 300A DC. For 125 V AC/DC applications, the 50A specification is sufficient for the 375 mA fuse rating.

Q: What certifications do the substitute parts carry?

A: Both Littelfuse substitutes carry CSA and UR certifications. The original MS 375 carried CE, CSA, and cURus certifications. CSA and UR certifications are maintained across all parts, ensuring regulatory compliance for North American applications.

Q: Are the substitute parts RoHS compliant?

A: Yes. Both Littelfuse substitutes are ROHS3 compliant. The original MS 375 RoHS status was not specified. This provides environmental compliance improvement for new designs.