Equivalent & Substitute Parts for 066302.5ZRLL

Part Overview

The Littelfuse 066302.5ZRLL is a 2.5 A, 250 V AC board mount fuse with slow blow response characteristics, designed for through-hole radial mounting in vertical orientation. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing design support and production continuity. The part belongs to the LT-5™ 663 series and meets multiple international approval standards including UL, VDE, CSA, and CCC certification.

Substiute Parts

066302.5ZRLL

Littelfuse Inc.In Stock: 1150066302.5ZRLL Datasheet

Current PartRFQ

37212500001

Littelfuse Inc.In Stock: 1637337212500001 Datasheet

DirectRFQ

0034.6619

SCHURTER Inc.In Stock: 48810034.6619 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 066302.5ZRLL is determined by strict alignment of the following critical parameters:

Primary Matching Criteria:

• Current Rating: 2.5 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)
• Fuse Type: Board Mount, Cartridge Style Excluded (exact match required)
• Package / Case: Radial, Can, Vertical (exact match required)

Secondary Compatibility Factors:

• Breaking Capacity @ Rated Voltage: 35 A minimum
• RoHS3 Compliance: Required for environmental and regulatory alignment
• Approval Agencies: Overlap in certifications (UL, VDE, CCC, CSA)

Both identified substitute parts meet all primary matching criteria and maintain compatibility with the original design specifications.

Parameter Comparison

Engineering Selection Recommendations

Littelfuse 37212500001 (TR5® 372 Series)

This substitute is manufactured by the same supplier as the original part and maintains identical electrical specifications for current, voltage, and response characteristics. The part is active in production with substantial inventory availability (16,275 pcs). It carries the same RoHS3 compliance and overlapping approval certifications (CCC, VDE, SEMKO). The melting I²t value of 35 is lower than the original 55, and the height dimension is reduced by 0.018" (0.45mm), which may require PCB layout verification. This option provides direct manufacturer continuity.

SCHURTER 0034.6619 (MST 250 Series)

This substitute provides equivalent electrical performance with additional DC voltage rating capability (125 V DC) and extended operating temperature range (-55°C ~ 125°C). The breaking capacity for DC applications is higher at 50 A. The melting I²t value of 30 is lower than the original specification. Physical dimensions are identical to the original part (0.335" Dia x 0.335" H). This option is suitable for applications requiring enhanced thermal performance or dual AC/DC voltage operation.

Both substitutes are active production parts with established supply chains and full RoHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can 37212500001 be used as a direct replacement for 066302.5ZRLL?

A: Yes, 37212500001 meets all primary electrical and mechanical matching criteria. However, the reduced height dimension (0.315" vs 0.333") requires verification that PCB footprint and clearance specifications remain satisfied in your application.

Q: What is the significance of the different melting I²t values?

A: The melting I²t parameter defines the thermal energy required to melt the fuse element. The original part specifies 55, while substitutes provide 35 (Littelfuse) and 30 (SCHURTER). Lower values indicate faster thermal response. Verify that your circuit protection requirements align with the substitute's thermal characteristics.

Q: Is the SCHURTER 0034.6619 suitable for DC applications?

A: The SCHURTER part includes a 125 V DC voltage rating, making it suitable for circuits operating at DC voltages up to 125 V. The original 066302.5ZRLL does not specify DC voltage capability. Select this substitute only if your application requires DC voltage protection.

Q: Are there packaging differences between these substitutes?

A: Yes. The original part packaging is not specified. The Littelfuse 37212500001 is supplied in Cut Tape (CT) packaging, while the SCHURTER 0034.6619 is supplied in Bulk packaging. Verify that your procurement and assembly processes accommodate these packaging formats.

Q: Which approval certifications are common across all three parts?

A: All three parts carry CCC and VDE certifications. The original and Littelfuse substitute share CSA and SEMKO approvals. The SCHURTER substitute includes cURus, KC, and PSE/JET certifications. Confirm that your application requirements align with the certification profile of your selected substitute.

Q: Can dimensional differences affect PCB assembly?

A: Yes. The Littelfuse substitute is 0.018" shorter in height, while the SCHURTER substitute matches the original height exactly. Verify that your PCB footprint, solder joint clearances, and component placement specifications accommodate the selected substitute's physical dimensions.