Littelfuse 0663002.ZRLL Board Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0663002.ZRLL is a 2 A, 250 V AC board mount fuse with slow blow response characteristics, designed for through-hole radial mounting in vertical orientation. This part is classified as obsolete, making identification of active equivalent and substitute components essential for ongoing production and maintenance applications. Substitute parts must maintain identical electrical ratings and mechanical compatibility to ensure proper circuit protection without redesign.

Substiute Parts

0663002.ZRLL

Littelfuse Inc.In Stock: 7000663002.ZRLL Datasheet

Current PartRFQ

37212000001

Littelfuse Inc.In Stock: 20202037212000001 Datasheet

DirectRFQ

0034.6618

SCHURTER Inc.In Stock: 55800034.6618 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following mandatory parameters:

• Current Rating: 2 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Response Time: Slow Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Radial, Can, Vertical (exact match required)
• Breaking Capacity @ Rated Voltage: 35 A minimum (exact match required)

Two substitute parts meet these criteria:

1. Littelfuse 37212000001 (TR5® 372 Series) - Active status, alternative packaging
2. SCHURTER 0034.6618 (MST 250 Series) - Active status, extended DC voltage rating

Both substitutes maintain the core electrical and mechanical specifications required for direct board-level replacement of the obsolete 0663002.ZRLL.

Parameter Comparison

Engineering Selection Recommendations

Littelfuse 37212000001 is the primary substitute for the obsolete 0663002.ZRLL. Both parts are manufactured by Littelfuse, share identical electrical ratings (2 A, 250 V AC, slow blow), and maintain the same mounting and package geometry. The TR5® 372 series is in active production with high inventory availability. Minor dimensional variation in height (0.315" vs. 0.333") is within typical PCB layout tolerances for radial through-hole components. This part is suitable for direct replacement in AC-only applications.

SCHURTER 0034.6618 serves as an alternative substitute with extended operational capabilities. The MST 250 series maintains all core AC electrical specifications while adding 125 V DC voltage rating and extended operating temperature range (-55°C ~ 125°C). This part is appropriate for applications requiring dual AC/DC voltage protection or operation in wider temperature environments. The identical breaking capacity (35 A AC) and matching slow blow response ensure equivalent circuit protection. Dimensional variation (0.335" H vs. 0.333" H) is negligible for standard PCB applications.

Both substitutes carry ROHS3 compliance and appropriate regulatory certifications (CCC, CSA, VDE, UL, SEMKO). Selection between the two depends on application voltage requirements and environmental operating conditions.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 37212000001 be used as a direct replacement for the 0663002.ZRLL?

A: Yes. Both parts share identical current rating (2 A), AC voltage rating (250 V), response time (slow blow), mounting type (through hole), and breaking capacity (35 A). The minor height difference (0.315" vs. 0.333") does not affect PCB compatibility for standard radial through-hole layouts.

Q: What is the difference between the two substitute parts?

A: The Littelfuse 37212000001 is optimized for AC applications with identical specifications to the main part. The SCHURTER 0034.6618 adds 125 V DC voltage rating and extends the operating temperature range to -55°C ~ 125°C, making it suitable for applications requiring dual AC/DC protection or extreme temperature environments.

Q: Are there packaging differences between these substitutes?

A: Yes. The Littelfuse 37212000001 is supplied in Cut Tape (CT) packaging, while the SCHURTER 0034.6618 is supplied in Bulk packaging. Packaging selection depends on production volume and assembly line requirements.

Q: Do all three parts have the same physical dimensions?

A: The diameter is identical (0.335" / 8.50mm) across all three parts. Height varies slightly: 0.333" H (main part), 0.315" H (Littelfuse substitute), and 0.335" H (SCHURTER substitute). These variations are within standard PCB design tolerances for radial through-hole components.

Q: Which substitute should I choose for a new design?

A: For AC-only circuits operating within -40°C ~ 85°C, either substitute is acceptable. The Littelfuse 37212000001 offers continuity with the original manufacturer. For applications requiring DC voltage protection or extended temperature operation, the SCHURTER 0034.6618 provides additional capability.

Q: Are all substitutes RoHS compliant?

A: Yes. All three parts (main and both substitutes) are ROHS3 compliant and meet applicable regulatory certifications including CCC, VDE, and UL standards.