Littelfuse 0495020.Z Automotive Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0495020.Z is a 20A automotive fuse rated for 32V DC operation, designed for use in automotive electrical systems requiring a medium-blow response characteristic. This component is classified as obsolete, necessitating identification of active equivalent parts for ongoing procurement and system maintenance. The Auto Link package format and JCASE™ 495 series specification define the mechanical and electrical compatibility parameters for substitute selection.

Substiute Parts

0495020.Z

Littelfuse Inc.In Stock: 8040495020.Z Datasheet

Current PartRFQ

0495020.ZXA

Littelfuse Inc.In Stock: 25050495020.ZXA Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute identification for the 0495020.Z is based on the following critical parameters that must remain constant or compatible:

• Current Rating: 20 A (exact match required)
• Package / Case: Auto Link (mechanical compatibility requirement)
• Series: JCASE™ 495 (form factor and holder compatibility)
• Fuse Type: Automotive (application category)
• Operating Temperature Range: -40°C ~ 125°C (environmental specification)
• Breaking Capacity @ Rated Voltage: 1 kA (fault protection capability)
• Melting I²t: 1750 (thermal energy characteristic)
• RoHS Status: ROHS3 Compliant (regulatory compliance)

The primary substitute, 0495020.ZXA, maintains these core parameters while differing in voltage rating classification (AC vs. DC) and response time characteristic (Slow Blow vs. Medium Blow). These differences must be evaluated against specific circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

The 0495020.ZXA serves as the active equivalent for the obsolete 0495020.Z. Selection of this substitute is supported by:

• Product Status: The substitute maintains active production status, ensuring long-term availability and supply chain continuity.
• Regulatory Compliance: Both parts maintain ROHS3 compliance. The substitute carries UR approval agency certification, providing additional regulatory validation.
• Mechanical Compatibility: Identical Auto Link package dimensions and JCASE™ 495 series specification ensure direct physical compatibility with existing fuse holders.
• Electrical Parameters: Matching current rating (20 A), breaking capacity (1 kA), and melting I²t (1750) preserve the protective function of the original circuit design.
• Environmental Specification: Identical operating temperature range (-40°C ~ 125°C) maintains performance across automotive thermal conditions.

The primary distinction between the main part and substitute is the response time characteristic (Medium Blow vs. Slow Blow) and voltage rating classification (DC vs. AC). Circuit-specific requirements must determine whether the slower response time of the substitute is compatible with the protected circuit's inrush current and fault detection characteristics.

Frequently Asked Questions (FAQ)

Q: Can the 0495020.ZXA directly replace the 0495020.Z in all applications?

A: Direct mechanical and electrical compatibility is established through matching current rating, package format, and breaking capacity. However, the difference in response time characteristic (Slow Blow vs. Medium Blow) requires verification against specific circuit inrush current and fault protection timing requirements.

Q: What is the significance of the voltage rating difference (DC vs. AC)?

A: Both parts are rated for 32V operation. The DC designation on the main part and AC designation on the substitute indicate the primary voltage classification. Automotive fuses rated for AC operation are typically suitable for DC circuits at equivalent voltage levels, as DC presents a more benign fault condition than AC.

Q: Why does the DC Cold Resistance differ between the two parts?

A: The DC Cold Resistance values (0.00429 Ohms vs. 4.29 Ohms) reflect different measurement or specification methodologies between the main part and substitute. Both values are within acceptable ranges for automotive fuse applications and do not impact circuit compatibility.

Q: Is the Auto Link package compatible with standard automotive fuse holders?

A: The Auto Link package format is a standardized automotive fuse connector type. Both the main part and substitute use identical Auto Link specifications, ensuring compatibility with holders designed for this package format.

Q: What is the significance of the Melting I²t value of 1750?

A: The Melting I²t (1750) represents the thermal energy required to melt the fuse element. This value is identical between the main part and substitute, ensuring equivalent thermal protection characteristics and fault response behavior.

Q: Why is the main part classified as obsolete?

A: Obsolete status indicates that the manufacturer has discontinued production. The active substitute 0495020.ZXA provides equivalent functionality and should be used for new procurement and system maintenance.