Littelfuse 0446004.ZR Surface Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0446004.ZR is a 4A 350VAC/125VDC surface mount board fuse in 2-SMD gull wing package configuration. This component is classified as obsolete, making identification of active equivalent parts essential for ongoing production and maintenance applications. The part delivers fast-blow response characteristics suitable for circuit protection in industrial and commercial electronics requiring dual voltage rating capability.

Substiute Parts

0446004.ZR

Littelfuse Inc.In Stock: 9510446004.ZR Datasheet

Current PartRFQ

0446004.ZRP

Littelfuse Inc.In Stock: 7990446004.ZRP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete 0446004.ZR is determined by strict equivalence across the following critical parameters:

• Current Rating: 4 A (exact match required)
• Voltage Rating - AC: 350 V (exact match required)
• Voltage Rating - DC: 125 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Package / Case: 2-SMD, Gull Wing (exact match required)
• Breaking Capacity @ Rated Voltage: 100A AC, 50A DC (exact match required)
• Melting I²t: 17 (exact match required)
• Operating Temperature Range: -40°C ~ 125°C (exact match required)
• DC Cold Resistance: 0.024 Ohms (exact match required)

The substitute part 0446004.ZRP maintains identical electrical and mechanical specifications while offering active product status and improved compliance characteristics.

Parameter Comparison

Engineering Selection Recommendations

The 0446004.ZRP is the direct active equivalent for the obsolete 0446004.ZR. Selection of the substitute part is justified by:

• Identical electrical performance across all rated parameters (current, voltage AC/DC, breaking capacity, melting I²t, and cold resistance)
• Identical mechanical configuration (surface mount, 2-SMD gull wing package, dimensions)
• Identical thermal operating range (-40°C ~ 125°C)
• Active product status ensuring ongoing availability and supply chain continuity
• ROHS3 compliance of the substitute part versus non-compliance of the main part
• Tape & Reel packaging of the substitute part supports automated assembly processes

For applications requiring the original part specifications, the 0446004.ZRP provides complete functional and physical compatibility with the added benefit of current product status and improved regulatory compliance.

Frequently Asked Questions (FAQ)

Q: Can the 0446004.ZRP be used as a direct replacement for the 0446004.ZR?

A: Yes. The 0446004.ZRP is a parametric equivalent with identical electrical ratings (4A, 350VAC, 125VDC), response time (fast blow), package configuration (2-SMD gull wing), and mechanical dimensions. The substitute part is electrically and mechanically interchangeable.

Q: What is the difference between the main part and the substitute?

A: The primary differences are product status (obsolete versus active), packaging format (unspecified versus Tape & Reel), RoHS compliance (non-compliant versus ROHS3 compliant), and approval agencies (CSA/METI/UL versus CSA/UL). All electrical and mechanical specifications are identical.

Q: Why is the 0446004.ZR classified as obsolete?

A: Product status is determined by manufacturer lifecycle decisions. The active equivalent 0446004.ZRP ensures continued access to functionally identical fuse components.

Q: Are there any compatibility concerns when switching from 0446004.ZR to 0446004.ZRP?

A: No compatibility concerns exist. Both parts share identical current ratings, voltage ratings, response characteristics, package type, and physical dimensions. PCB layouts and circuit designs require no modification.

Q: What does the Tape & Reel packaging of the 0446004.ZRP provide?

A: Tape & Reel packaging supports automated pick-and-place assembly processes, improving manufacturing efficiency compared to bulk packaging formats.

Q: Is the ROHS3 compliance of the 0446004.ZRP a functional advantage?

A: ROHS3 compliance reflects adherence to current environmental and material restriction regulations. For applications subject to regulatory requirements or customer specifications mandating RoHS compliance, the 0446004.ZRP meets these requirements while the 0446004.ZR does not.