LR250303SR Equivalent & Substitute Parts

Part Overview

The LR250303SR is a 30 A, 250V cartridge fuse holder designed for chassis mount applications with 3 circuits and screw terminal connections. This component is classified as obsolete, making identification of suitable alternatives essential for ongoing system maintenance and new design implementations. The part accommodates Class R fuses with 0.563" diameter x 2" length dimensions and operates at unlimited moisture sensitivity levels.

Substiute Parts

LR250303SR

Littelfuse Inc.In Stock: 789LR250303SR Datasheet

Current PartRFQ

LFR250303S

Littelfuse Inc.In Stock: 978LFR250303S Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The LFR250303S qualifies as a direct substitute based on the following critical parameters:

• Current Rating: 30 A (identical)
• Voltage Rating: 250V (identical)
• Number of Circuits: 3 (identical)
• Fuse Size: 0.563" Dia x 2" L (identical)
• Fuse Type: Cartridge (identical)
• Termination Style: Screw Terminal (identical)
• Class R Fuse Compatibility: Confirmed

The primary functional difference is the mounting configuration: the LR250303SR uses chassis mount, while the LFR250303S uses DIN rail mount. This distinction affects physical installation but does not alter electrical performance or fuse compatibility.

Parameter Comparison

Engineering Selection Recommendations

The LFR250303S is the direct electrical and mechanical equivalent for the obsolete LR250303SR. Both components maintain identical electrical specifications: 30 A current rating, 250V voltage rating, 3-circuit configuration, and Class R cartridge fuse compatibility.

The LFR250303S offers the advantage of active product status, ensuring continued availability and supply chain reliability. Additionally, the LFR250303S meets ROHS3 compliance requirements, whereas the LR250303SR is non-compliant. For new designs or system upgrades, the LFR250303S is the appropriate selection.

The mounting configuration difference (chassis mount versus DIN rail) requires mechanical integration assessment. If the original chassis mount form factor is mandatory, alternative solutions outside this substitute list may be necessary. If DIN rail mounting is acceptable within the system architecture, the LFR250303S provides full electrical compatibility with improved compliance status.

Frequently Asked Questions (FAQ)

Q: Can the LFR250303S directly replace the LR250303SR in existing installations?

A: Electrical compatibility is confirmed. The LFR250303S maintains identical current rating (30 A), voltage rating (250V), circuit count (3), fuse size (0.563" x 2"), and Class R fuse compatibility. Physical installation requires DIN rail mounting capability instead of chassis mount. Mechanical integration assessment is necessary before implementation.

Q: What is the significance of the mounting type difference?

A: The LR250303SR is designed for direct chassis mounting with screw terminals. The LFR250303S is designed for DIN rail mounting. Both use identical screw terminal connections for electrical termination. The mounting difference affects only the physical installation method and does not alter electrical performance or fuse compatibility.

Q: Why is RoHS compliance status different between these parts?

A: The LR250303SR predates current RoHS3 requirements and is classified as non-compliant. The LFR250303S is an active product meeting ROHS3 compliance standards. For applications subject to RoHS3 regulatory requirements, the LFR250303S is the appropriate selection.

Q: Are both parts compatible with Class R fuses?

A: Yes. Both the LR250303SR and LFR250303S are specified for use with Class R fuses in the 0.563" diameter x 2" length format. Fuse selection remains identical regardless of which fuseholder is used.

Q: What is the difference between a fuse holder and a fuse block?

A: The LR250303SR is classified as a holder, while the LFR250303S is classified as a block. Both are cartridge fuseholder devices with identical electrical specifications. The terminology reflects design architecture differences, but electrical performance and fuse compatibility are equivalent.