GSA 125-R Equivalent & Substitute Parts

Part Overview

The GSA 125-R is a 125 mA, 250 V AC/DC ceramic cartridge fuse manufactured by Bel Fuse Inc. with slow-blow response characteristics. This component is classified as obsolete, necessitating identification of active equivalent parts to maintain system functionality and ensure continued availability for replacement and new designs. The fuse requires a 3AB or 3AG holder and operates across a temperature range of -55°C to 125°C.

Substiute Parts

GSA 125-R

Bel Fuse Inc.In Stock: 1051GSA 125-R Datasheet

Current PartRFQ

0326.125MXP

Littelfuse Inc.In Stock: 9370326.125MXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 0326.125MXP from Littelfuse Inc. qualifies as a direct substitute for the GSA 125-R based on the following critical parameters:

• Current Rating: Both parts are rated at 125 mA
• Voltage Rating (AC): Both parts are rated at 250 V
• Fuse Type: Both are ceramic cartridge fuses
• Response Time: Both exhibit slow-blow characteristics
• Package / Case: Both use 3AB, 3AG, 1/4" x 1-1/4" form factor
• Mounting Type: Both require a holder
• Operating Temperature Range: Both operate from -55°C to 125°C
• RoHS Compliance: Both are ROHS3 compliant

The substitute part maintains electrical and mechanical compatibility with the original specification, enabling direct replacement in existing applications.

Parameter Comparison

Engineering Selection Recommendations

The 0326.125MXP from Littelfuse Inc. is the appropriate substitute for the obsolete GSA 125-R. The substitute part maintains all critical electrical parameters (current rating, voltage rating, response time) and mechanical specifications (package form factor, dimensions, mounting requirements). Both parts carry equivalent regulatory approvals and compliance certifications (ROHS3, REACH Unaffected, EAR99 classification). The substitute part is currently in active production status, ensuring long-term availability and supply chain continuity. The minor dimensional variance (0.002" length difference) falls within standard manufacturing tolerances for this component category and does not affect holder compatibility.

Frequently Asked Questions (FAQ)

Q: Can the 0326.125MXP directly replace the GSA 125-R in existing applications?

A: Yes. Both parts share identical current ratings (125 mA), voltage ratings (250 V AC), fuse type (ceramic cartridge), response characteristics (slow-blow), and package specifications (3AB, 3AG, 1/4" x 1-1/4"). The parts are mechanically and electrically interchangeable.

Q: Are there any dimensional differences between these parts?

A: The length dimension differs by 0.002" (GSA 125-R: 1.252" vs. 0326.125MXP: 1.250"). This variance is within standard manufacturing tolerances and does not affect compatibility with standard 3AB or 3AG fuse holders.

Q: What is the significance of the product status difference?

A: The GSA 125-R is classified as obsolete, meaning Bel Fuse Inc. no longer manufactures this part. The 0326.125MXP is in active production status, ensuring continued availability for procurement and replacement needs.

Q: Do both parts meet the same regulatory requirements?

A: Both parts are ROHS3 compliant and REACH unaffected. The GSA 125-R carries CE, CSA, and cULus approvals, while the 0326.125MXP carries CE approval. Both parts are classified under ECCN EAR99 and HTSUS 8536.10.0040.

Q: Are there differences in electrical characteristics that affect substitution?

A: The breaking capacity and melting I²t values differ between the parts (GSA 125-R: 35A breaking capacity, 0.323 I²t vs. 0326.125MXP: 100A breaking capacity, 0.1 I²t). These parameters do not affect the substitution decision for standard circuit protection applications where the 125 mA current rating and 250 V voltage rating are the controlling specifications.