GSAP 300-R Equivalent & Substitute Parts

Part Overview

The GSAP 300-R is a 300 mA ceramic cartridge fuse rated for 250 V AC, manufactured by Bel Fuse Inc. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system maintenance and repair applications. The fuse features slow-blow response characteristics and is housed in a 3AB, 3AG form factor with axial through-hole mounting. Due to its discontinued status, sourcing equivalent parts from active manufacturers ensures supply chain continuity.

Substiute Parts

GSAP 300-R

Bel Fuse Inc.In Stock: 895GSAP 300-R Datasheet

Current PartRFQ

0325.300MXP

Littelfuse Inc.In Stock: 7630325.300MXP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The substitute part 0325.300MXP from Littelfuse Inc. qualifies as a functional equivalent based on the following critical parameters:

• Current Rating: Both parts are rated at 300 mA, ensuring identical load protection characteristics
• AC Voltage Rating: Both parts are rated for 250 V AC, matching the primary operating voltage specification
• Fuse Type & Response: Both are ceramic cartridge fuses with slow-blow response, providing equivalent protection behavior
• Package & Form Factor: Both use the 3AB, 3AG form factor with 1/4" x 1-1/4" (Axial) dimensions, ensuring mechanical and electrical compatibility in existing circuit designs
• Mounting Configuration: Both feature through-hole mounting, compatible with standard PCB and panel-mount applications
• Operating Temperature: Both operate across the -55°C ~ 125°C range, maintaining performance in equivalent environmental conditions
• Compliance Standards: Both hold CE, CSA, and UL certifications, meeting international safety and regulatory requirements

The 0325.300MXP additionally provides 125 V DC rating and higher breaking capacity specifications, offering enhanced capability without compromising AC-rated performance.

Parameter Comparison

Engineering Selection Recommendations

The 0325.300MXP from Littelfuse Inc. is the qualified substitute for the obsolete GSAP 300-R. Selection is based on:

• Product Status: The GSAP 300-R is obsolete; the 0325.300MXP is active and currently manufactured, ensuring long-term availability
• Electrical Equivalence: Identical current and AC voltage ratings guarantee direct functional replacement in 250 V AC circuits
• Regulatory Compliance: Both parts hold CE and CSA certifications. The 0325.300MXP carries UL certification, meeting or exceeding the original cULus approval
• Physical Compatibility: Matching package dimensions and through-hole mounting enable direct PCB and panel installation without design modification
• Enhanced Specifications: The 0325.300MXP provides additional DC voltage rating and higher breaking capacity, offering improved performance margins in mixed-voltage or high-fault-current applications

Frequently Asked Questions (FAQ)

Q: Can the 0325.300MXP directly replace the GSAP 300-R in existing designs?

A: Yes. Both parts share identical current ratings (300 mA), AC voltage ratings (250 V), ceramic cartridge construction, slow-blow response, and 3AB/3AG form factor. Physical dimensions and through-hole mounting are compatible, enabling direct substitution without circuit modification.

Q: What is the significance of the DC voltage rating on the 0325.300MXP?

A: The 0325.300MXP includes a 125 V DC rating, whereas the GSAP 300-R does not specify DC performance. In AC-only applications, this difference is not relevant. In mixed-voltage or DC circuits, the 0325.300MXP provides additional capability.

Q: How do the melting I²t values differ, and does this affect substitution?

A: The GSAP 300-R has a melting I²t of 1.85, while the 0325.300MXP has 0.69. The lower I²t value indicates faster thermal response. Both are slow-blow fuses; the difference reflects manufacturing variations between manufacturers. For AC-rated applications at 250 V and 300 mA, both provide equivalent protection.

Q: Are there any compliance differences between the two parts?

A: Both parts are ROHS3 compliant and REACH unaffected. The GSAP 300-R holds CE, CSA, and cULus certifications. The 0325.300MXP holds CE, CSA, and UL certifications. UL certification is equivalent to cULus for fuse applications, ensuring regulatory equivalence.

Q: What is the impact of the higher breaking capacity on the 0325.300MXP?

A: The 0325.300MXP has a breaking capacity of 100 A AC and 10 kA DC, compared to 35 A for the GSAP 300-R. Higher breaking capacity indicates the fuse can safely interrupt larger fault currents. This does not affect normal operation but provides improved safety margins in high-fault-current environments.

Q: Are the DC cold resistance values significant for AC applications?

A: For AC-only applications, DC cold resistance (3.17 Ohms vs. 3.22 Ohms) is not operationally significant. The values are nearly identical and fall within normal manufacturing tolerances for ceramic cartridge fuses.