Littelfuse TR5® 373 1.25A 250VAC Board Mount Fuse 37311250430

Part Overview

The Littelfuse 37311250430 is a 1.25A 250VAC board mount fuse with fast blow response characteristics, designed for through-hole radial mounting in electronic circuits requiring overcurrent protection. This component is classified as Active product status with full CSA and cULus approval certifications. Alternative equivalent parts become necessary when addressing supply chain constraints, regional certification requirements, or specific approval agency mandates for particular applications.

Substiute Parts

37311250430

Littelfuse Inc.In Stock: 86537311250430 Datasheet

Current PartRFQ

37311250410

Littelfuse Inc.In Stock: 135237311250410 Datasheet

DirectRFQ

37011250410

Littelfuse Inc.In Stock: 179537011250410 Datasheet

Parametric EquivalentRFQ

37011250430

Littelfuse Inc.In Stock: 75137011250430 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 37311250430 is determined by strict equivalence across the following critical parameters: current rating (1.25A), voltage rating (250VAC), response time (Fast Blow), mounting type (Through Hole), package configuration (Radial, Can, Vertical), breaking capacity (50A), and physical dimensions (0.335" Dia x 0.315" H). All identified substitute parts maintain these core electrical and mechanical specifications. Differences in series designation (TR5® 373 versus TR5® 370), melting I²t values, and approval agency certifications do not preclude substitution when the primary electrical parameters remain identical.

Parameter Comparison

Engineering Selection Recommendations

All four parts maintain Active product status and ROHS3 compliance. The 37311250430 and 37311250410 share identical TR5® 373 series designation and melting I²t value (0.2), differing only in packaging configuration. The 37011250410 and 37011250430 belong to the TR5® 370 series with melting I²t of 0.31, and carry expanded approval agency certifications including CCC, cURus, PSE, SEMKO, and VDE compared to the CSA and cULus certifications of the TR5® 373 variants. Selection between TR5® 373 and TR5® 370 series should be based on regional regulatory requirements and specific approval agency mandates for the target application. All parts are electrically and mechanically interchangeable within the specified parameter constraints.

Frequently Asked Questions (FAQ)

Q: Can 37011250410 or 37011250430 replace 37311250430 in all applications? A: Yes, provided the application does not mandate CSA or cULus certification exclusively. The TR5® 370 series parts carry broader international certifications (CCC, cURus, PSE, SEMKO, VDE) and are electrically equivalent across all critical parameters.

Q: What is the significance of the melting I²t difference between TR5® 373 (0.2) and TR5® 370 (0.31) series? A: Melting I²t represents the thermal energy required to melt the fuse element. The TR5® 370 series requires higher thermal energy, which may affect response characteristics in specific circuit conditions. Selection should align with circuit design specifications and thermal requirements.

Q: Are all substitute parts available in equivalent inventory quantities? A: Inventory levels vary. The 37311250410 has 1242 pcs in stock, 37011250410 has 1750 pcs, and 37011250430 has 667 pcs, compared to 762 pcs for the main part 37311250430. Verify current availability with your supplier.

Q: Do packaging differences exist between these parts? A: All four parts share identical packaging configuration: Radial, Can, Vertical through-hole mounting with 0.335" diameter and 0.315" height (8.50mm x 8.00mm). No mechanical adaptation is required for board-level substitution.

Q: Which part should be selected for applications requiring international compliance? A: The TR5® 370 series parts (37011250410 and 37011250430) provide broader international certification coverage. Select based on specific regional requirements: CCC for China, PSE for Japan, SEMKO for Sweden, VDE for Europe, and cURus for North America.