5MT 100-R Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The 5MT 100-R is a 100 mA, 250 V AC/DC glass cartridge fuse manufactured by Bel Fuse Inc. in a 5mm x 20mm form factor with medium blow response time. This part is classified as obsolete, making equivalent substitute parts necessary for ongoing system maintenance and new designs. Substitute parts must maintain identical electrical ratings, mechanical dimensions, and functional characteristics to ensure direct compatibility in existing fuse holder assemblies.

Substiute Parts

5MT 100-R

Bel Fuse Inc.In Stock: 7375MT 100-R Datasheet

Current PartRFQ

20101000001

LittelfuseIn Stock: 87920101000001 Datasheet

SimilarRFQ

20101000021

Littelfuse Inc.In Stock: 105620101000021 Datasheet

SimilarRFQ

20101000431P

Littelfuse Inc.In Stock: 119320101000431P Datasheet

SimilarRFQ

BK/GMC-100-R

Eaton - Electronics DivisionIn Stock: 828BK/GMC-100-R Datasheet

SimilarRFQ

BK1/GMC-100-R

Eaton - Electronics DivisionIn Stock: 770BK1/GMC-100-R Datasheet

SimilarRFQ

GMC-100-R

Eaton - Electronics DivisionIn Stock: 1061GMC-100-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 5MT 100-R is determined by strict equivalence across the following critical parameters:

• Current Rating: 100 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Medium Blow (exact match required)
• Mounting Type: Requires Holder (exact match required)

All substitute parts listed below meet these criteria. Variations in secondary parameters such as breaking capacity, melting I²t, DC cold resistance, and operating temperature range do not disqualify substitution but should be evaluated for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts are active products with current manufacturing status, providing supply continuity for the obsolete 5MT 100-R. Selection should be based on the following criteria:

Littelfuse 201 Series (20101000001, 20101000021, 20101000431P): These parts carry cULus certification and are suitable for applications requiring North American compliance. The 20101000431P variant includes integrated holder packaging, eliminating the need for separate holder procurement. Operating temperature range is -25°C to 70°C.

Eaton GMC Series (BK/GMC-100-R, BK1/GMC-100-R, GMC-100-R): These parts provide broader international certification coverage including CSA, UL, and KC-MARK approvals. The BK1/GMC-100-R variant includes additional MITI certification. All three variants are functionally equivalent with identical electrical characteristics. Operating temperature range is not specified in available data.

Compliance Considerations: All substitute parts maintain ROHS3 compliance and REACH unaffected status, matching the original part's environmental regulatory standing. Approval agency selection should align with target market requirements and system certification needs.

Frequently Asked Questions (FAQ)

Q: Can the 5MT 100-R be directly replaced with any of the listed substitute parts?

A: Yes. All listed parts maintain identical current rating (100 mA), voltage rating (250 V AC), fuse type (cartridge glass), package dimensions (5mm x 20mm), response time (medium blow), and mounting type (requires holder). Direct substitution is electrically and mechanically compatible.

Q: What is the difference between the Littelfuse 20101000001 and 20101000021 parts?

A: Both parts are functionally equivalent with identical electrical ratings and certifications. The primary difference is inventory availability and potential manufacturing date variations. Both are suitable for direct substitution.

Q: Does the 20101000431P include a fuse holder?

A: The 20101000431P is packaged in Tape & Reel format with holder integration, as indicated by the "5mm x 20mm w/Holder" package designation. The other Littelfuse variants (20101000001, 20101000021) require a separate holder assembly.

Q: Are there operating temperature differences between substitute options?

A: The Littelfuse 201 series operates from -25°C to 70°C. The Eaton GMC series does not specify an operating temperature range in available documentation. The original 5MT 100-R operates from -55°C to 125°C. For applications requiring extended temperature operation, verify specific environmental requirements against available substitute specifications.

Q: Which substitute part has the lowest DC cold resistance?

A: The Eaton GMC series parts (BK/GMC-100-R, BK1/GMC-100-R, GMC-100-R) have a DC cold resistance of 4.775 Ohms, compared to 11.9 Ohms for the original 5MT 100-R. The Littelfuse 201 series does not specify DC cold resistance values.

Q: What certifications should I prioritize for my application?

A: Selection depends on target market and system certification requirements. Littelfuse parts carry cULus certification suitable for North American markets. Eaton parts provide broader international coverage with CSA, UL, and KC-MARK certifications. Verify your system's certification requirements before final part selection.

Q: Is the breaking capacity difference significant for substitution?

A: The original 5MT 100-R and Eaton GMC series have 35A breaking capacity, while Littelfuse 201 series parts have 80A breaking capacity. Both values exceed the 100 mA rated current by a substantial margin. Breaking capacity differences do not affect substitution eligibility for standard circuit protection applications.