Littelfuse 37011250430 Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 37011250430 is a 1.25 A, 250 V AC/DC board mount fuse with fast blow response characteristics, designed for through-hole radial mounting in TR5® 370 series applications. This component is actively produced and maintains full compliance with international safety standards including CCC, cURus, PSE, SEMKO, and VDE certifications. Substitute parts are identified when equivalent electrical and mechanical parameters are required due to inventory constraints, design revisions, or supply chain considerations.

Substiute Parts

37011250430

Littelfuse Inc.In Stock: 75137011250430 Datasheet

Current PartRFQ

37011250410

Littelfuse Inc.In Stock: 179537011250410 Datasheet

DirectRFQ

37311250410

Littelfuse Inc.In Stock: 135237311250410 Datasheet

Parametric EquivalentRFQ

0034.6015

SCHURTER Inc.In Stock: 17410034.6015 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 37011250430 are classified based on strict electrical and mechanical parameter alignment:

Direct Manufacturer Equivalents (Littelfuse): Parts 37011250410 and 37311250410 share identical current rating (1.25 A), voltage rating (250 V AC), response time (Fast Blow), mounting type (Through Hole), and package configuration (Radial, Can, Vertical). Both maintain the same operating temperature range (-40°C ~ 85°C) and RoHS3 compliance. These parts differ only in series designation (TR5® 370 vs. TR5® 373) and internal electrical characteristics (Melting I²t values: 0.31 vs. 0.2).

Cross-Manufacturer Equivalent (SCHURTER): Part 0034.6015 matches all critical electrical parameters: 1.25 A current rating, 250 V AC voltage rating, Fast Blow response, Through Hole mounting, and Radial, Can, Vertical package. Physical dimensions are 0.335" Dia x 0.335" H (8.50mm x 8.50mm), representing a 0.05mm height variance from the main part. Breaking capacity is specified at 35 A versus 50 A for Littelfuse parts.

Substitution eligibility is determined by matching: current rating, voltage rating, response time classification, mounting method, and package form factor.

Parameter Comparison

Engineering Selection Recommendations

Littelfuse 37011250410: Direct manufacturer equivalent with identical electrical specifications and breaking capacity (50 A). Maintains full certification alignment with CCC, cURus, PSE, SEMKO, and VDE. Suitable for direct substitution in TR5® 370 series applications. Higher inventory availability (1750 pcs) supports supply chain continuity.

Littelfuse 37311250410: Parametric equivalent from TR5® 373 series with matching electrical ratings and breaking capacity. Certifications limited to CSA and cULus; does not include PSE or SEMKO approvals present in the main part. Melting I²t value (0.2) differs from main part (0.31), indicating different thermal response characteristics. Selection requires confirmation that application requirements align with TR5® 373 series specifications and reduced certification scope.

SCHURTER 0034.6015: Cross-manufacturer equivalent with matching electrical parameters and operating temperature range. Physical height variance of 0.05mm (8.50mm vs. 8.00mm) requires PCB layout verification for clearance compatibility. Breaking capacity rated at 35 A versus 50 A for Littelfuse parts; applications requiring higher fault current protection should retain Littelfuse options. Certification scope includes CCC, cURus, and VDE but excludes PSE and SEMKO. Melting I²t (0.68) indicates slower thermal response compared to main part (0.31).

Frequently Asked Questions (FAQ)

Q: Can 37011250410 be used as a direct replacement for 37011250430?

A: Yes. Both parts share identical current rating (1.25 A), voltage rating (250 V AC), response time (Fast Blow), mounting configuration (Through Hole Radial), and physical dimensions (0.335" Dia x 0.315" H). Certification profiles and breaking capacity (50 A) are equivalent. The parts differ only in series designation within the TR5® 370 family.

Q: What is the significance of the Melting I²t parameter in substitute selection?

A: Melting I²t defines the thermal energy required to melt the fuse element and is provided in the specifications. The main part 37011250430 specifies 0.31, while 37311250410 specifies 0.2 and 0034.6015 specifies 0.68. These values indicate different thermal response profiles. Applications with specific thermal protection requirements should reference the original design specification to confirm compatibility.

Q: Is the 0.05mm height difference between 37011250430 and 0034.6015 significant?

A: The main part measures 0.315" H (8.00mm), while the SCHURTER equivalent measures 0.335" H (8.50mm). This 0.05mm variance requires verification against PCB layout, component clearance requirements, and any height-restricted mounting environments. Mechanical fit confirmation is necessary before implementation.

Q: Why does 0034.6015 have a lower breaking capacity (35 A vs. 50 A)?

A: Breaking capacity represents the maximum fault current the fuse can safely interrupt at rated voltage. The SCHURTER part is rated for 35 A breaking capacity compared to 50 A for Littelfuse equivalents. Applications requiring protection against higher fault currents should retain Littelfuse options. Verify the application's maximum available fault current against the selected part's breaking capacity rating.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All parts listed—37011250430, 37011250410, 37311250410, and 0034.6015—maintain ROHS3 Compliant status and are REACH Unaffected, supporting environmental and regulatory requirements.

Q: What certification differences exist between substitute options?

A: The main part 37011250430 and direct equivalent 37011250410 carry CCC, cURus, PSE, SEMKO, and VDE certifications. The parametric equivalent 37311250410 is certified only by CSA and cULus. The cross-manufacturer equivalent 0034.6015 carries CCC, cURus, and VDE certifications but lacks PSE and SEMKO approvals. Applications requiring specific regional certifications should confirm alignment with the selected substitute part's approval agency list.