Littelfuse 20108000021 Equivalent & Substitute Parts

Part Overview

The Littelfuse 20108000021 is an 800 mA, 250 V AC glass cartridge fuse in 5mm x 20mm form factor with medium blow response time. This fuse is designed for circuit protection in AC applications and requires a compatible holder for installation. The part maintains active product status with ROHS3 compliance and cULus approval. Substitute parts are identified to provide alternative sourcing options while maintaining equivalent electrical and mechanical performance within specified parameters.

Substiute Parts

20108000021

Littelfuse Inc.In Stock: 76520108000021 Datasheet

Current PartRFQ

0034.2515

SCHURTER Inc.In Stock: 17750034.2515 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by matching the following critical parameters:

• Current Rating: 800 mA (exact match required)
• Voltage Rating - AC: 250 V (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Response Time: Medium Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 80A (exact match required)

The SCHURTER Inc. part 0034.2515 meets all substitution criteria. This part provides equivalent electrical performance for AC applications at the specified current and voltage ratings, with identical physical dimensions and breaking capacity.

Parameter Comparison

Engineering Selection Recommendations

Both the Littelfuse 20108000021 and SCHURTER 0034.2515 are active products with ROHS3 compliance and REACH unaffected status. The Littelfuse part carries cULus approval. Both parts are electrically and mechanically equivalent for 250 V AC, 800 mA applications in 5mm x 20mm form factor.

The SCHURTER part provides additional DC voltage rating capability (125 V DC) and extended operating temperature range (-40°C ~ 85°C versus -25°C ~ 70°C), which may be advantageous in applications requiring broader environmental performance. The Melting I²t value differs between parts (1.1 versus 1.68), reflecting different thermal characteristics within the medium blow response classification.

Selection between these parts should be based on specific application requirements, approval certifications needed, and inventory availability.

Frequently Asked Questions (FAQ)

Q: Can the SCHURTER 0034.2515 be used as a direct replacement for the Littelfuse 20108000021?

A: Yes, for AC applications at 250 V and 800 mA. Both parts share identical current rating, AC voltage rating, fuse type, package dimensions, response time, and breaking capacity. The SCHURTER part is mechanically and electrically compatible in the same holder.

Q: What is the significance of the different Melting I²t values?

A: Melting I²t (1.1 for Littelfuse, 1.68 for SCHURTER) indicates the thermal energy required to melt the fuse element. Both parts maintain medium blow response classification, but the different values reflect manufacturing variations within this response category. This does not affect substitutability for the specified application parameters.

Q: Does the SCHURTER part's DC voltage rating affect AC-only applications?

A: No. The SCHURTER part's 125 V DC rating is an additional capability that does not impact performance in AC circuits. For AC applications, the 250 V AC rating is the controlling specification for both parts.

Q: Are there any approval or certification differences between these parts?

A: The Littelfuse part carries cULus approval. The SCHURTER part does not list a specific approval agency in the provided data. Approval requirements should be verified against application-specific standards and regulatory requirements.

Q: Can these fuses be used interchangeably in the same holder?

A: Yes. Both parts have identical physical dimensions (5mm x 20mm, 0.205" Dia x 0.787" L) and require the same holder type. Physical installation is interchangeable.