Equivalent & Substitute Parts for 3JS 2

Part Overview

The 3JS 2 is a 2A 350VAC/140VDC slow-blow glass cartridge fuse in 2AG form factor (5mm x 15mm axial). Manufactured by Bel Fuse Inc., this through-hole component is designed for circuit protection in applications requiring moderate current ratings and dual voltage operation. The main part number 3JS 2 carries an obsolete product status, necessitating identification of active equivalent alternatives for ongoing procurement and design continuity.

Substiute Parts

3JS 2

Bel Fuse Inc.In Stock: 7723JS 2 Datasheet

Current PartRFQ

3JS 2-R

Bel Fuse Inc.In Stock: 20203JS 2-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3JS 2 is determined by strict equivalence across the following critical parameters:

• Current Rating: 2 A (exact match required)
• Voltage Rating - AC: 350 V (exact match required)
• Voltage Rating - DC: 140 V (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 2AG, 5mm x 15mm (Axial) (exact match required)
• Mounting Type: Through Hole (exact match required)
• Breaking Capacity @ Rated Voltage: 100A AC, 150A DC (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)

The substitute part 3JS 2-R meets all critical electrical and mechanical parameters, differing only in product status (active vs. obsolete), packaging configuration (bulk vs. standard), and minor variations in DC cold resistance and melting I²t values within acceptable engineering tolerances.

Parameter Comparison

Engineering Selection Recommendations

The 3JS 2-R is the direct active equivalent for the obsolete 3JS 2. Both parts maintain identical electrical ratings, mechanical form factors, and thermal operating ranges. The 3JS 2-R carries active product status with improved RoHS3 compliance, making it the appropriate selection for new designs and ongoing procurement. Both parts hold equivalent regulatory approvals (CE, CSA, cURus, PSE), ensuring compatibility with existing certification requirements. The minor variation in DC cold resistance (0.094 Ohms vs. 0.063 Ohms) and melting I²t (22.6 vs. 23) remain within acceptable engineering tolerances for slow-blow fuse applications at this current rating.

Frequently Asked Questions (FAQ)

Q: Can 3JS 2-R be used as a direct replacement for 3JS 2 in existing designs?

A: Yes. The 3JS 2-R is electrically and mechanically equivalent to the 3JS 2 across all critical parameters: current rating, voltage ratings (AC/DC), fuse type, response time, package form factor, and breaking capacity. Both parts are approved by the same regulatory agencies.

Q: What is the difference between 3JS 2 and 3JS 2-R?

A: The primary differences are product status (3JS 2 is obsolete; 3JS 2-R is active), packaging configuration (3JS 2-R is supplied in bulk), and compliance status (3JS 2-R is RoHS3 compliant). Electrical and mechanical specifications are equivalent.

Q: Are there any thermal or performance differences between these parts?

A: Both parts operate across the same temperature range (-55°C ~ 125°C) and maintain identical breaking capacity ratings (100A AC, 150A DC). Minor variations in DC cold resistance and melting I²t are within acceptable tolerances for slow-blow fuse applications.

Q: What certifications do these fuses carry?

A: Both 3JS 2 and 3JS 2-R hold CE, CSA, cURus, and PSE approvals, ensuring compliance with international safety standards.

Q: Is the 2AG package form factor standard across both parts?

A: Yes. Both parts use the 2AG cartridge form factor with identical dimensions (5mm x 15mm axial), ensuring mechanical compatibility in through-hole applications.