Bel Fuse Inc. 5ST 100 Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 5ST 100 is a 100 mA, 250 V AC/DC slow-blow glass cartridge fuse in 5mm x 20mm form factor, designed for circuit protection in industrial and commercial applications. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new design implementations. Substitute parts must maintain identical electrical ratings, mechanical dimensions, and functional characteristics to ensure direct compatibility in existing fuse holders.

Substiute Parts

5ST 100

Bel Fuse Inc.In Stock: 9725ST 100 Datasheet

Current PartRFQ

5ST 100-R

Bel Fuse Inc.In Stock: 68035ST 100-R Datasheet

DirectRFQ

0034.3107

SCHURTER Inc.In Stock: 47610034.3107 Datasheet

DirectRFQ

0218.100MXP

Littelfuse Inc.In Stock: 105850218.100MXP Datasheet

DirectRFQ

0218.100TXP

Littelfuse Inc.In Stock: 12430218.100TXP Datasheet

DirectRFQ

0218.100VXP

Littelfuse Inc.In Stock: 9730218.100VXP Datasheet

DirectRFQ

0218.100HXP

Littelfuse Inc.In Stock: 8090218.100HXP Datasheet

SimilarRFQ

0218.100MXF4P

Littelfuse Inc.In Stock: 12070218.100MXF4P Datasheet

SimilarRFQ

GDC-100MA

Eaton - Electronics DivisionIn Stock: 985GDC-100MA Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 5ST 100 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)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Slow Blow (exact match required)
• Physical Dimensions: 5mm x 20mm (exact match required)
• Mounting Configuration: Requires Holder (exact match required)

All substitute parts listed below meet these criteria and are therefore electrically and mechanically interchangeable with the 5ST 100. Differences in secondary parameters such as melting I²t, DC cold resistance, and breaking capacity do not preclude substitution when primary electrical and mechanical specifications are identical.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts listed above are electrically and mechanically equivalent to the 5ST 100 and are suitable for direct replacement in existing applications. Selection among available substitutes should be based on the following factors:

Product Status and Availability: The 5ST 100-R (Bel Fuse Inc.) is the direct active equivalent of the obsolete 5ST 100, maintaining identical electrical and mechanical specifications while offering improved RoHS3 compliance and higher inventory availability.

Regulatory Compliance: All active substitute parts are RoHS3 compliant, addressing environmental and regulatory requirements. The original 5ST 100 is RoHS non-compliant and should be replaced in new designs or systems requiring compliance certification.

Certification Coverage: Littelfuse 218 series parts (0218.100MXP, 0218.100TXP, 0218.100VXP, 0218.100HXP) provide comprehensive international approvals including CCC, CE, CSA, UL, and VDE. SCHURTER 0034.3107 offers CCC, cURus, and VDE certifications. Eaton GDC-100MA provides cURus and IMQ certifications. Selection should align with system certification requirements.

Inventory and Lead Time: Littelfuse 0218.100MXP offers the highest inventory level (10,490 units), followed by Bel Fuse 5ST 100-R (6,712 units) and SCHURTER 0034.3107 (4,715 units), supporting rapid procurement for production environments.

Frequently Asked Questions (FAQ)

Q: Can the 5ST 100-R directly replace the obsolete 5ST 100?

A: Yes. The 5ST 100-R is the active equivalent of the 5ST 100, maintaining identical current rating (100 mA), voltage rating (250 V AC), response time (slow blow), and physical dimensions (5mm x 20mm). The primary difference is product status (active vs. obsolete) and RoHS3 compliance.

Q: Are all listed substitute parts mechanically compatible with existing 5ST 100 fuse holders?

A: Yes. All substitute parts conform to the 5mm x 20mm cartridge fuse standard and are designed for use in standard 5x20mm fuse holders. Physical dimensions are equivalent across all listed parts.

Q: What is the significance of the different melting I²t values among substitute parts?

A: Melting I²t is a secondary thermal characteristic that does not affect substitution eligibility when primary electrical parameters (current rating, voltage rating, response time) are identical. All listed parts are slow-blow fuses rated at 100 mA, 250 V and will function identically in circuit protection applications.

Q: Does the higher breaking capacity of 0218.100MXF4P (80 A vs. 35 A) affect its suitability as a substitute?

A: No. Breaking capacity is the maximum fault current the fuse can safely interrupt. A higher breaking capacity does not compromise functionality in applications designed for the 5ST 100. The 0218.100MXF4P remains electrically and mechanically equivalent for all standard circuit protection applications.

Q: Which substitute part should be selected for new product designs requiring environmental compliance?

A: Any of the active, RoHS3-compliant substitute parts are suitable for new designs. The 5ST 100-R (Bel Fuse Inc.) is recommended as the primary choice due to direct manufacturer equivalence. Littelfuse 218 series parts (0218.100MXP, 0218.100TXP, 0218.100VXP, 0218.100HXP) offer broader international certification coverage if multi-region compliance is required.

Q: Are there any temperature or operating condition limitations that would restrict substitution?

A: No. All substitute parts maintain the identical operating temperature range (-55°C to 125°C) as the 5ST 100. Substitution is unrestricted across the specified temperature envelope.