Equivalent & Substitute Parts for 3JS 500

Part Overview

The 3JS 500 is a 500 mA slow-blow glass cartridge fuse rated for 350 V AC and 140 V DC operation. Designed for through-hole mounting in the 2AG form factor (5mm x 15mm axial), this component is classified as obsolete. Due to its discontinued status, identifying functionally equivalent substitute parts is essential for ongoing system maintenance and new design implementations where this specification remains applicable.

Substiute Parts

3JS 500

Bel Fuse Inc.In Stock: 11303JS 500 Datasheet

Current PartRFQ

3JS 500-R

Bel Fuse Inc.In Stock: 16543JS 500-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3JS 500 is determined by strict equivalence across the following electrical and mechanical parameters:

• Current Rating: 500 mA (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 3JS 500-R from Bel Fuse Inc. meets all substitution criteria and is identified as a direct equivalent.

Parameter Comparison

Engineering Selection Recommendations

The 3JS 500-R is the direct substitute for the obsolete 3JS 500. Both components are manufactured by Bel Fuse Inc. and share identical electrical and mechanical specifications across all critical parameters.

The 3JS 500-R carries Active product status, ensuring ongoing availability and supply chain continuity. The substitute achieves ROHS3 compliance, whereas the original part is RoHS non-compliant. Both components maintain equivalent approval certifications (CE, CSA, cURus), with the original part additionally holding PSE approval.

Minor variations exist in DC Cold Resistance (0.62 Ohms versus 0.84 Ohms) and Melting I²t (1.6 versus 1.55), which remain within acceptable tolerance for functional equivalence in this fuse category and do not affect substitution validity.

Frequently Asked Questions (FAQ)

Q: Can the 3JS 500-R directly replace the 3JS 500 in existing designs?

A: Yes. The 3JS 500-R meets all electrical and mechanical substitution criteria, including current rating, voltage ratings, fuse type, response time, package form factor, and operating temperature range.

Q: What is the difference between the 3JS 500 and 3JS 500-R?

A: Both parts are functionally equivalent. The primary differences are product status (obsolete versus active), RoHS compliance level, and minor variations in DC Cold Resistance and Melting I²t values. These variations do not affect functional substitution.

Q: Are there compliance considerations when switching from 3JS 500 to 3JS 500-R?

A: The 3JS 500-R achieves ROHS3 compliance, whereas the original 3JS 500 is RoHS non-compliant. Both maintain CE, CSA, and cURus certifications. System designers should verify that ROHS3 compliance aligns with their application requirements.

Q: Is the 2AG package form factor critical for substitution?

A: Yes. The 2AG form factor (5mm x 15mm axial) is a mechanical requirement for through-hole mounting compatibility. Any substitute must maintain this exact package specification.

Q: What is the significance of the Melting I²t and DC Cold Resistance differences?

A: These parameters reflect minor manufacturing variations between the obsolete and active versions. Both values remain within acceptable tolerance for the 500 mA, 350 V AC / 140 V DC fuse specification and do not compromise functional equivalence.