Littelfuse 0664002.ZRLL Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0664002.ZRLL is a 2 A, 250 V AC/DC board mount fuse with slow blow response characteristics, designed for through-hole radial mounting in vertical orientation. This component belongs to the LT-5™ 664 series and is classified as obsolete. Due to its obsolete status, equivalent substitute parts from active product lines are necessary to maintain design continuity and ensure ongoing component availability for new production and field replacements.

Substiute Parts

0664002.ZRLL

Littelfuse Inc.In Stock: 10700664002.ZRLL Datasheet

Current PartRFQ

38212000000

Littelfuse Inc.In Stock: 1480138212000000 Datasheet

DirectRFQ

0034.6918

SCHURTER Inc.In Stock: 17400034.6918 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0664002.ZRLL are qualified based on strict electrical and mechanical parameter matching:

Qualifying Parameters for Substitution:

• Current Rating: 2 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded)
• Mounting Type: Through Hole
• Package / Case: Radial, Can, Vertical
• Response Time: Slow Blow
• Breaking Capacity @ Rated Voltage: 100 A
• Operating Temperature Range: -40°C ~ 85°C
• RoHS Compliance: ROHS3 Compliant

The two identified substitute parts meet all critical electrical parameters and mechanical form factors. Variations in secondary parameters such as melting I²t, DC cold resistance, and physical dimensions (within tolerance) do not preclude substitution when primary electrical and mechanical specifications align.

Parameter Comparison

Engineering Selection Recommendations

Littelfuse 38212000000 (TR5® 382 Series)

This substitute is from an active Littelfuse product line and represents the primary equivalent. It maintains identical electrical specifications (2 A, 250 V, slow blow, 100 A breaking capacity) and mechanical form factor. The part is actively manufactured and widely available. Approval agencies include CCC, cURus, KC, PSE/JET, SEMKO, and VDE. The melting I²t value of 17.8 is marginally higher than the original 16, and DC cold resistance is lower at 0.028 Ohms, both of which represent acceptable operational variations within the slow blow fuse category. Height dimension is 8.00mm versus the original 8.45mm, a difference of 0.45mm that remains within typical PCB layout tolerances for through-hole radial components.

SCHURTER 0034.6918 (MXT 250 Series)

This substitute from SCHURTER Inc. meets all critical electrical and mechanical parameters. It is an active product with approval from CCC, cURus, KC, PSE/JET, and VDE. The melting I²t matches the original at 16. Physical dimensions are 8.50mm diameter x 8.50mm height, representing a 0.05mm increase in height compared to the original, which is negligible for PCB mounting. This part provides an alternative source from a different manufacturer, supporting supply chain diversification.

Both substitutes are suitable for direct replacement in applications requiring 2 A, 250 V slow blow fuse protection with through-hole radial mounting.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 38212000000 be used as a direct replacement for the 0664002.ZRLL?

A: Yes. Both parts share identical current rating (2 A), voltage rating (250 V AC), response time (slow blow), mounting type (through hole), package style (radial, can, vertical), and breaking capacity (100 A). The minor differences in melting I²t (17.8 vs. 16) and DC cold resistance (0.028 vs. 0.039 Ohms) do not affect functional compatibility in slow blow fuse applications.

Q: What is the significance of the height dimension difference between the original and substitute parts?

A: The 0664002.ZRLL has a height of 8.45mm, while the 38212000000 measures 8.00mm and the 0034.6918 measures 8.50mm. These variations of less than 0.5mm are within standard PCB layout tolerances for through-hole radial components and do not require design modification for typical applications.

Q: Are there packaging differences between the substitutes?

A: Yes. The 0664002.ZRLL was supplied in bulk packaging. The 38212000000 is available in cut tape (CT) packaging, while the 0034.6918 is supplied in bulk. Packaging selection should be based on procurement and assembly requirements.

Q: Do all substitute parts meet the same regulatory approvals?

A: The 0664002.ZRLL carries approvals from CCC, CSA, KTL, METI, SEMKO, UL, and VDE. The 38212000000 is approved by CCC, cURus, KC, PSE/JET, SEMKO, and VDE. The 0034.6918 is approved by CCC, cURus, KC, PSE/JET, and VDE. While approval agencies differ slightly, all parts meet major international standards. Design engineers should confirm that substitute approvals align with specific application requirements.

Q: Why is the original part obsolete?

A: The 0664002.ZRLL (LT-5™ 664 series) has been discontinued by Littelfuse. The TR5® 382 series (38212000000) represents the current active product line offering equivalent functionality and specifications.

Q: Can I use the SCHURTER 0034.6918 if I need a Littelfuse part?

A: The SCHURTER 0034.6918 is electrically and mechanically equivalent and meets the same performance specifications. However, if your application or procurement specification requires a Littelfuse manufacturer part, the 38212000000 is the appropriate choice.