3SB 12 Equivalent & Substitute Parts

Part Overview

The 3SB 12 is a 12 A, 125 V AC/DC slow blow glass cartridge fuse manufactured by Bel Fuse Inc. This component is designed for use with 3AB and 3AG fuse holders and provides circuit protection in applications requiring a 1/4" x 1-1/4" form factor. The main part (3SB 12) carries an obsolete product status, making identification of active equivalent parts essential for ongoing system support and procurement.

Substiute Parts

3SB 12

Bel Fuse Inc.In Stock: 8923SB 12 Datasheet

Current PartRFQ

3SB 12-R

Bel Fuse Inc.In Stock: 22613SB 12-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 3SB 12-R qualifies as a direct substitute for the 3SB 12 based on identical electrical and mechanical parameters. Substitution is valid when the following criteria are met:

• Current Rating: 12 A (identical)
• Voltage Rating (AC): 125 V (identical)
• Response Time: Slow Blow (identical)
• Fuse Type: Cartridge, Glass (identical)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (identical)
• Breaking Capacity @ Rated Voltage: 10 kA (identical)
• Melting I²t: 1277 (identical)
• Operating Temperature Range: -55°C ~ 125°C (identical)
• DC Cold Resistance: 0.008 Ohms (identical)
• Size / Dimension: 0.250" Dia x 1.252" L (6.35 mm x 31.80 mm) (identical)

The 3SB 12-R maintains full compatibility with all mechanical mounting requirements and electrical performance specifications of the original 3SB 12.

Parameter Comparison

Engineering Selection Recommendations

The 3SB 12-R is the appropriate selection for applications currently using the obsolete 3SB 12. Both parts maintain identical electrical performance and mechanical compatibility. The 3SB 12-R offers the advantage of active product status, ensuring continued availability and supply chain reliability. Additionally, the 3SB 12-R achieves ROHS3 compliance, whereas the original 3SB 12 is non-compliant. The 3SB 12-R carries expanded regulatory approvals including cULus certification, providing enhanced compliance coverage for North American applications.

Frequently Asked Questions (FAQ)

Q: Can the 3SB 12-R be used as a direct replacement for the 3SB 12?

A: Yes. The 3SB 12-R is a direct substitute. All electrical parameters (current rating, voltage rating, response time, breaking capacity, melting I²t, and DC cold resistance) and mechanical specifications (package type, dimensions, and mounting requirements) are identical.

Q: What is the difference between the 3SB 12 and 3SB 12-R?

A: The primary differences are product status and regulatory compliance. The 3SB 12 is obsolete, while the 3SB 12-R is active. The 3SB 12-R is ROHS3 compliant and includes cULus certification, whereas the 3SB 12 is RoHS non-compliant and does not carry cULus approval.

Q: Are there any compatibility issues when substituting the 3SB 12-R for the 3SB 12?

A: No. Both parts are compatible with 3AB and 3AG fuse holders and maintain identical form factors (0.250" Dia x 1.252" L). No mechanical or electrical modifications are required.

Q: What certifications does the 3SB 12-R carry?

A: The 3SB 12-R is certified by CE, CSA, cULus, and PSE. The original 3SB 12 carries CE, CSA, PSE, and UL certifications.

Q: Is the 3SB 12-R RoHS compliant?

A: Yes. The 3SB 12-R is ROHS3 compliant. The original 3SB 12 is RoHS non-compliant.