FWA-350B Equivalent & Substitute Parts

Part Overview

The FWA-350B is a 350A cartridge fuse manufactured by Eaton - Bussmann Electrical Division, rated for 150 VAC and 150 VDC operation. This bolt-mount fuse cartridge is designed for industrial and electrical applications requiring high current protection with a breaking capacity of 100kA AC and 20kA DC. The part is currently active in production with 798 units in stock. Substitute parts are identified when equivalent electrical and mechanical parameters align with application requirements, enabling procurement flexibility and supply chain continuity.

Substiute Parts

FWA-350B

Eaton - Bussmann Electrical DivisionIn Stock: 838FWA-350B Datasheet

Current PartRFQ

L15S350.T

LittelfuseIn Stock: 894L15S350.T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FWA-350B is determined by the following critical parameters:

• Current Rating: Must be 350A
• Voltage Rating - AC: Must be 150 VAC minimum
• Voltage Rating - DC: Must be 150 VDC minimum
• Fuse Type: Must be Cartridge
• Mounting Type: Must be Bolt Mount
• Package / Case: Must be Cylindrical with Blade Terminal (Bolt)
• Breaking Capacity: Must meet or exceed 100kA AC and 20kA DC
• Physical Dimensions: Must be compatible with 1.000" Dia x 1.156" L envelope

The Littelfuse L15S350.T meets the primary electrical and mechanical criteria with matching current rating, AC voltage rating, mounting configuration, and breaking capacity. A variance exists in DC voltage rating (100 VDC vs. 150 VDC), which represents a design difference in the substitute part's DC performance specification.

Parameter Comparison

Engineering Selection Recommendations

Both the FWA-350B and L15S350.T are active production parts with current inventory availability. Selection between these parts depends on application-specific DC voltage requirements:

• FWA-350B is specified for applications requiring full 150 VDC rating with CE and UR certifications.
• L15S350.T is specified for applications operating at 100 VDC or lower, with expanded certifications including CSA in addition to CE and UR.

The dimensional variance (1.156" vs. 1.157" length) is negligible and does not affect mechanical compatibility in standard bolt-mount installations. Both parts share identical AC voltage rating, current rating, breaking capacity, and physical diameter.

Frequently Asked Questions (FAQ)

Q: Can L15S350.T replace FWA-350B in all applications?

A: Substitution is valid only when the application operates at 100 VDC or lower. If the circuit requires 150 VDC operation, the FWA-350B is the specified part. Both parts are electrically and mechanically compatible for AC applications at 150 VAC.

Q: What is the significance of the DC voltage rating difference?

A: The DC voltage rating indicates the maximum safe operating voltage for DC circuits. The FWA-350B supports 150 VDC, while the L15S350.T supports 100 VDC. Exceeding the rated DC voltage of a fuse can compromise its protective function.

Q: Are the physical dimensions identical?

A: The diameter is identical at 1.000" (25.40mm). The length differs by 0.001" (0.04mm), which is within manufacturing tolerance and does not affect bolt-mount installation compatibility.

Q: Do both parts have the same breaking capacity?

A: Yes. Both the FWA-350B and L15S350.T have a breaking capacity of 100kA AC and 20kA DC at rated voltage, ensuring equivalent fault protection performance.

Q: What certifications apply to each part?

A: FWA-350B holds CE and UR certifications. L15S350.T holds CE, CSA, and UR certifications. Both meet the same core safety standards; L15S350.T includes additional CSA certification for North American applications.

Q: Is packaging type a substitution factor?

A: Packaging (Bulk vs. Box) does not affect electrical or mechanical compatibility. It is a procurement and logistics consideration only.