Bel Fuse Inc. 3JS 3 Fuse Cartridge Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 3JS 3 is a 3 A, 350 V AC / 140 V DC slow-blow glass fuse cartridge in 2AG package format (5mm x 15mm axial). This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system maintenance and repair applications. The 3JS 3-R represents the active production equivalent with identical electrical and mechanical specifications.

Substiute Parts

3JS 3

Bel Fuse Inc.In Stock: 7523JS 3 Datasheet

Current PartRFQ

3JS 3-R

Bel Fuse Inc.In Stock: 16963JS 3-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3JS 3 is determined by strict equivalence across the following critical parameters:

• Current Rating: 3 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)
• Package / Case: 2AG, 5mm x 15mm (Axial) (exact match required)
• Response Time: Slow Blow (exact match required)
• Breaking Capacity: 100 A AC / 150 A DC (exact match required)

The 3JS 3-R is a direct functional equivalent manufactured by Bel Fuse Inc. with identical electrical performance and mechanical form factor. The primary distinction is product status: the 3JS 3 is obsolete, while the 3JS 3-R is in active production. Secondary differences include packaging format (bulk vs. standard) and minor variations in DC cold resistance (0.045 Ω vs. 0.037 Ω) and melting I²t rating (55.2 vs. 55), which remain within acceptable tolerance for circuit protection applications.

Parameter Comparison

Engineering Selection Recommendations

The 3JS 3-R is the direct replacement for the obsolete 3JS 3. Both components share identical electrical ratings, mechanical dimensions, and regulatory certifications (CE, CSA, cURus, PSE). The 3JS 3-R is in active production status, ensuring availability for new designs and maintenance applications.

For applications requiring RoHS3 compliance, the 3JS 3-R is the appropriate selection. The minor difference in DC cold resistance (0.037 Ω vs. 0.045 Ω) and melting I²t rating (55 vs. 55.2) does not affect circuit protection performance in standard applications and remains within manufacturer tolerance specifications.

Frequently Asked Questions (FAQ)

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

A: Yes. The 3JS 3-R is electrically and mechanically equivalent to the 3JS 3. Both components have identical current ratings (3 A), voltage ratings (350 V AC / 140 V DC), fuse type (cartridge, glass), package format (2AG, 5mm x 15mm axial), and response time (slow blow). The 3JS 3-R is the active production equivalent.

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

A: The primary difference is product status: the 3JS 3 is obsolete, while the 3JS 3-R is in active production. Secondary differences include packaging format and minor variations in DC cold resistance (0.045 Ω vs. 0.037 Ω) and melting I²t rating (55.2 vs. 55). The 3JS 3-R also carries ROHS3 compliance, whereas the 3JS 3 is RoHS non-compliant.

Q: Are there any compatibility concerns when substituting the 3JS 3-R for the 3JS 3?

A: No compatibility concerns exist. Both components are through-hole mounted in identical 2AG package format with matching electrical specifications and regulatory certifications. Direct socket compatibility is confirmed.

Q: What regulatory certifications apply to both the 3JS 3 and 3JS 3-R?

A: Both components carry CE, CSA, cURus, and PSE approvals, confirming compliance with international safety standards for circuit protection devices.

Q: Does the 3JS 3-R meet RoHS requirements?

A: Yes. The 3JS 3-R is ROHS3 compliant. The original 3JS 3 is RoHS non-compliant. For applications requiring RoHS compliance, the 3JS 3-R is the appropriate selection.