Littelfuse 20101000021 Glass Cartridge Fuse 100mA 250VAC 5x20mm Equivalent & Substitute Parts

Part Overview

The Littelfuse 20101000021 is a glass cartridge fuse rated for 100 mA at 250 V AC/DC with a 5mm x 20mm form factor. This fuse is designed for applications requiring medium-blow response characteristics and is housed in a glass body requiring a dedicated fuse holder. The part maintains active product status with full cULus approval and ROHS3 compliance. Substitute parts are identified when identical electrical and mechanical parameters are maintained across the same fuse category and package specification.

Substiute Parts

20101000021

Littelfuse Inc.In Stock: 105620101000021 Datasheet

Current PartRFQ

20101000021P

Littelfuse Inc.In Stock: 105320101000021P Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the Littelfuse 20101000021 are identified based on 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)
• Package Dimensions: 5mm x 20mm (exact match required)
• Response Time: Medium Blow (exact match required)
• Breaking Capacity: 80A (exact match required)
• Melting I²t: 0.022 (exact match required)

The substitute part 20101000021P meets all these criteria and is therefore classified as a parametric equivalent. Both parts share identical electrical performance characteristics, thermal response, and mechanical compatibility with standard 5x20mm fuse holders.

Parameter Comparison

Engineering Selection Recommendations

Both the Littelfuse 20101000021 and 20101000021P are active products with identical electrical and mechanical specifications. Selection between these parts may be based on inventory availability and supply chain considerations. Both parts carry cULus approval and maintain ROHS3 compliance, ensuring regulatory conformance for applications requiring these certifications. The interchangeability of these parts is confirmed by matching current rating, voltage rating, fuse type, package dimensions, response characteristics, and thermal performance parameters.

Frequently Asked Questions (FAQ)

Q: Can the 20101000021P be used as a direct replacement for the 20101000021?

A: Yes. Both parts are parametric equivalents with identical current rating (100 mA), voltage rating (250 V AC), fuse type (cartridge glass), package dimensions (5mm x 20mm), response time (medium blow), breaking capacity (80A), and melting I²t (0.022). They are mechanically and electrically interchangeable.

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

A: No. Both parts carry cULus approval, are ROHS3 compliant, and have REACH Unaffected status. Regulatory compliance is identical.

Q: What is the significance of the series designation difference (201 vs 201P)?

A: The series designation reflects internal Littelfuse product line organization. This does not affect electrical performance, mechanical compatibility, or functional equivalence.

Q: Do both parts require the same fuse holder?

A: Yes. Both parts are 5mm x 20mm cartridge fuses requiring a standard 5x20mm fuse holder. Mechanical compatibility is identical.

Q: What determines whether a fuse can substitute for another?

A: Substitution requires exact matching of current rating, voltage rating, fuse type, package dimensions, response time, breaking capacity, and melting I²t. All these parameters must be identical for electrical and thermal equivalence.