Bel Fuse Inc. 5HT 3.15 Ceramic Fuse - Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 5HT 3.15 is a 3.15 A, 250 V AC ceramic cartridge fuse in 5mm x 20mm form factor with slow-blow response characteristics. This part is classified as obsolete, making identification of active equivalent and substitute components essential for ongoing system support and new design implementations. The fuse requires a compatible holder for installation and is designed for applications requiring reliable overcurrent protection with ceramic construction and thermal stability across -55°C to 125°C operating range.

Substiute Parts

5HT 3.15

Bel Fuse Inc.In Stock: 10115HT 3.15 Datasheet

Current PartRFQ

5HT 3.15-R

Bel Fuse Inc.In Stock: 1355195HT 3.15-R Datasheet

DirectRFQ

0001.2509

SCHURTER Inc.In Stock: 388110001.2509 Datasheet

DirectRFQ

0034.2521

SCHURTER Inc.In Stock: 18710034.2521 Datasheet

SimilarRFQ

02153.15HXP

Littelfuse Inc.In Stock: 191502153.15HXP Datasheet

SimilarRFQ

BK1/S505-3.15-R

Eaton - Electronics DivisionIn Stock: 1790BK1/S505-3.15-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 5HT 3.15 is determined by strict alignment with the following electrical and mechanical parameters:

• Current Rating: 3.15 A (exact match required)
• Voltage Rating (AC): 250 V (minimum requirement)
• Fuse Type: Cartridge, Ceramic
• Package / Case: 5mm x 20mm (mechanical compatibility)
• Response Time: Slow Blow (functional equivalence)
• Breaking Capacity: 1.5 kA or higher (safety margin acceptable)

Substitute parts are classified into two categories:

Direct Equivalents meet all primary electrical and mechanical parameters with active product status and current manufacturing support.

Similar Substitutes meet core electrical specifications but may have variations in secondary parameters such as DC voltage rating, response time classification, breaking capacity, or thermal characteristics. These require engineering evaluation for specific application contexts.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: 5HT 3.15-R (Bel Fuse Inc.)

The 5HT 3.15-R is the direct active equivalent manufactured by the original supplier. It maintains identical electrical specifications (3.15 A, 250 V AC, slow-blow response, 1.5 kA breaking capacity) and mechanical form factor (5mm x 20mm). The part is ROHS3 compliant and carries the same approval certifications as the obsolete 5HT 3.15, with the addition of cURus certification. This part is recommended as the primary replacement for all applications previously using the 5HT 3.15.

Secondary Recommendations:

02153.15HXP (Littelfuse Inc.) provides full electrical and mechanical compatibility with identical current rating, AC voltage, slow-blow response, and 1.5 kA breaking capacity. ROHS3 compliance and comprehensive approval certifications (CCC, CE, CSA, KC, PSE, SEMKO, UL, VDE) support broad application deployment. The melting I²t value of 43.255 is higher than the original specification, which may affect thermal response characteristics in specific circuit designs.

BK1/S505-3.15-R (Eaton - Electronics Division) meets all primary electrical parameters with identical current, voltage, response time, and breaking capacity specifications. ROHS3 compliance and extensive certification coverage (BSI, CCC/CQC, CSA, cURus, IMQ, KC, PSE/JET, SEMKO, VDE) enable use across diverse regulatory environments. The melting I²t of 36.6 represents a moderate deviation from the original specification.

0001.2509 (SCHURTER Inc.) is electrically compatible for AC applications with enhanced DC voltage rating (300 V DC versus unspecified DC rating on original). This part is suitable for applications requiring dual AC/DC voltage protection. The melting I²t of 33.7 is within acceptable variance of the original 31.

Not Recommended: 0034.2521 (SCHURTER Inc.)

The 0034.2521 exhibits significant deviations from the original specification: medium-blow response time (versus slow-blow), reduced breaking capacity (1.0 kA versus 1.5 kA), lower melting I²t (20.4 versus 31), and restricted operating temperature range (-40°C to 85°C versus -55°C to 125°C). These parameters indicate functional incompatibility with the original design intent. This part is suitable only for applications with explicitly different thermal and response requirements.

Frequently Asked Questions (FAQ)

Q: Can I use 5HT 3.15-R as a direct replacement for the obsolete 5HT 3.15?

A: Yes. The 5HT 3.15-R is manufactured by Bel Fuse Inc. and maintains identical electrical specifications (3.15 A, 250 V AC, slow-blow response, 1.5 kA breaking capacity) and mechanical form factor (5mm x 20mm). It is the recommended primary replacement.

Q: What is the difference between "Direct" and "Similar" substitute classifications?

A: Direct substitutes meet all primary electrical and mechanical parameters with active product status. Similar substitutes meet core electrical specifications but may have variations in secondary parameters such as DC voltage rating, response time, breaking capacity, or thermal characteristics. Similar substitutes require engineering evaluation for specific application contexts.

Q: Why is 0034.2521 listed as "not recommended"?

A: The 0034.2521 has a medium-blow response time instead of slow-blow, reduced breaking capacity (1.0 kA versus 1.5 kA), lower melting I²t (20.4 versus 31), and restricted operating temperature range (-40°C to 85°C versus -55°C to 125°C). These deviations indicate functional incompatibility with the original design specification.

Q: Are all substitute parts ROHS3 compliant?

A: All active substitute parts listed are ROHS3 compliant. The original 5HT 3.15 is RoHS non-compliant. This compliance upgrade is standard for current manufacturing.

Q: Do all substitute parts have the same approval certifications?

A: No. While all substitute parts carry multiple certifications, the specific agencies vary. The 5HT 3.15-R includes cURus certification not present on the original. The 02153.15HXP and BK1/S505-3.15-R carry UL certification. Verify certification requirements for your specific application and regulatory jurisdiction.

Q: What does melting I²t represent, and why do substitute parts have different values?

A: Melting I²t is a thermal characteristic indicating the energy required to melt the fuse element. Variations in melting I²t among substitute parts reflect differences in element design and material composition. Higher values indicate slower thermal response; lower values indicate faster response. Select based on your circuit's thermal protection requirements.

Q: Can I use substitute parts with different DC voltage ratings in AC-only applications?

A: Yes. For AC-only applications, the AC voltage rating is the controlling parameter. Parts with higher DC voltage ratings (such as 0001.2509 with 300 V DC) are compatible with AC circuits rated at 250 V AC. The additional DC rating capability does not affect AC performance.

Q: What is the mechanical compatibility requirement for these fuses?

A: All listed substitute parts use the 5mm x 20mm cartridge form factor and require a compatible fuse holder. Verify that your existing fuse holder accepts this standard form factor before installation.