0RLS450.X Equivalent & Substitute Parts

Part Overview

The 0RLS450.X is a 450A 600VAC cylindrical cartridge fuse from Littelfuse Inc.'s POWR-GARD® RLS series. This component is classified as obsolete, requiring identification of active equivalent parts for continued system support. The fast-blow response characteristic and Class H rating make this fuse suitable for electrical and industrial applications requiring high current protection at 600VAC.

Substiute Parts

0RLS450.X

Littelfuse Inc.In Stock: 7440RLS450.X Datasheet

Current PartRFQ

KLSR450.X

Littelfuse Inc.In Stock: 1113KLSR450.X Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The KLSR450.X qualifies as a direct substitute based on the following critical parameters:

Matching Parameters:

• Current Rating: 450A (identical)
• Voltage Rating - AC: 600 VAC (identical)
• Response Time: Fast Blow (identical)
• Fuse Type: Cartridge (identical)
• Mounting Type: Requires Holder (identical)
• Package / Case: Cylindrical, Blade Terminals (identical)
• Approval Agency: CE, CSA, UL (identical)

Enhanced Capabilities: The KLSR450.X provides additional DC voltage rating (300 VDC) and superior breaking capacity (200kA AC, 20kA DC versus 10kA), making it suitable for applications requiring dual AC/DC operation or higher fault current environments.

Parameter Comparison

Engineering Selection Recommendations

The KLSR450.X is the active equivalent for the obsolete 0RLS450.X. Selection is based on:

Product Status: The 0RLS450.X is obsolete; the KLSR450.X is active and currently manufactured, ensuring long-term availability and supply chain continuity.

Electrical Compatibility: Both parts maintain identical 450A current rating and 600 VAC voltage rating, with matching fast-blow response characteristics and cartridge form factor.

Regulatory Compliance: Both parts carry CE, CSA, and UL approvals. The KLSR450.X additionally meets ROHS3 compliance standards, whereas the 0RLS450.X is RoHS non-compliant.

Physical Accommodation: The KLSR450.X has a longer physical length (13.374" versus 8.870"), requiring verification that the fuse holder and mounting space can accommodate the increased dimension.

Enhanced Performance: The KLSR450.X provides higher breaking capacity (200kA AC versus 10kA) and dual voltage capability (600 VAC / 300 VDC), offering greater protection margin in fault scenarios.

Frequently Asked Questions (FAQ)

Q: Can the KLSR450.X directly replace the 0RLS450.X in existing installations?

A: Electrical compatibility is confirmed for 450A 600 VAC applications. Physical accommodation must be verified, as the KLSR450.X is 4.504" longer. The fuse holder and mounting cavity must provide sufficient clearance for the longer cartridge length.

Q: What is the difference between Class H and Class RK1 ratings?

A: Class H and Class RK1 are distinct fuse classifications with different breaking capacities and application profiles. The 0RLS450.X is Class H with 10kA breaking capacity; the KLSR450.X is Class RK1 with 200kA AC breaking capacity. Verify that the fuse holder is rated for the substitute part's class designation.

Q: Does the KLSR450.X DC voltage rating affect AC-only applications?

A: No. The 300 VDC rating is an additional capability that does not impact AC operation. The 600 VAC rating remains the primary specification for AC applications.

Q: Why is the KLSR450.X longer than the 0RLS450.X?

A: The increased length accommodates the enhanced breaking capacity and dual voltage design. Physical space verification is required before substitution.

Q: Are both parts available with identical packaging?

A: The 0RLS450.X packaging is listed as "-" (unspecified); the KLSR450.X is supplied in Box packaging. Confirm packaging requirements for your procurement process.

Q: What is the RoHS compliance impact?

A: The 0RLS450.X is RoHS non-compliant; the KLSR450.X is ROHS3 compliant. For applications subject to RoHS regulations, the KLSR450.X is the required choice.