Bel Fuse Inc. 2JS 1.25 Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 2JS 1.25 is a slow-blow glass cartridge fuse rated for 1.25 A at 350 V AC and 140 V DC. This component is classified as obsolete, requiring identification of active equivalent parts for continued system support and procurement. The 2AG form factor (5mm x 15mm) with holder-based mounting remains a standard configuration in industrial and consumer applications. Locating functionally equivalent substitutes ensures design continuity and supply chain reliability for legacy equipment maintenance and new designs requiring this fuse specification.

Substiute Parts

2JS 1.25

Bel Fuse Inc.In Stock: 11722JS 1.25 Datasheet

Current PartRFQ

2JS 1.25-R

Bel Fuse Inc.In Stock: 13192JS 1.25-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete 2JS 1.25 is determined by strict equivalence across electrical and mechanical parameters. The primary substitute, 2JS 1.25-R, maintains identical specifications for current rating, AC/DC voltage ratings, fuse type, response time, package form factor, and breaking capacity. Both parts are manufactured by Bel Fuse Inc. and share the same 2AG cartridge configuration requiring standard fuse holders.

The key parameters governing substitution are:

• Current Rating: 1.25 A (exact match required)
• Voltage Ratings: 350 V AC / 140 V DC (exact match required)
• Fuse Type: Cartridge, Glass with Slow Blow response (exact match required)
• Package / Case: 2AG, 5mm x 15mm (exact match required)
• Mounting: Holder-based installation (exact match required)

The 2JS 1.25-R is the direct functional equivalent, with the primary distinction being product status transition from obsolete to active, along with improved RoHS3 compliance and enhanced DC cold resistance characteristics.

Parameter Comparison

Engineering Selection Recommendations

The 2JS 1.25-R is the direct substitute for the obsolete 2JS 1.25. Selection of the 2JS 1.25-R is supported by:

• Active product status ensuring ongoing availability and supply chain continuity
• Identical electrical ratings and mechanical form factor enabling direct replacement without circuit modification
• ROHS3 compliance meeting current environmental and regulatory requirements
• Enhanced DC cold resistance (0.127 Ohms vs. 0.195 Ohms) providing improved electrical performance
• Maintained approval certifications (CE, CSA, cURus, PSE) confirming regulatory acceptance

For applications requiring the 2JS 1.25 specification, the 2JS 1.25-R provides full functional equivalence with improved compliance status and performance characteristics.

Frequently Asked Questions (FAQ)

Q: Can the 2JS 1.25-R be used as a direct replacement for the 2JS 1.25?

A: Yes. The 2JS 1.25-R is electrically and mechanically identical to the 2JS 1.25 across all critical parameters: current rating, voltage ratings, fuse type, response time, package form factor, and breaking capacity. Direct substitution is supported without circuit modification.

Q: What is the difference between the 2JS 1.25 and 2JS 1.25-R?

A: The primary differences are product status (obsolete vs. active), RoHS compliance (non-compliant vs. ROHS3 compliant), and DC cold resistance (0.195 Ohms vs. 0.127 Ohms). Electrical and mechanical specifications remain identical.

Q: Does the 2JS 1.25-R require a different fuse holder than the 2JS 1.25?

A: No. Both parts use the 2AG form factor (5mm x 15mm) and require the same standard fuse holder. No hardware changes are necessary.

Q: Are the approval certifications equivalent between the two parts?

A: Both parts carry CE, CSA, and PSE certifications. The 2JS 1.25-R includes cURus certification, while the 2JS 1.25 includes UR certification. Both meet applicable regulatory requirements for their respective product statuses.

Q: What is the significance of the improved DC cold resistance in the 2JS 1.25-R?

A: The reduced DC cold resistance (0.127 Ohms vs. 0.195 Ohms) in the 2JS 1.25-R results in lower voltage drop across the fuse element during normal operation, improving overall circuit efficiency and thermal performance.