Littelfuse 0RLS225.X Fuse Cartridge - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0RLS225.X is a 225A, 600 VAC cylindrical fuse cartridge from the POWR-GARD® RLS series, designed for electrical and industrial applications requiring fast-blow protection. This part is classified as obsolete, making identification of suitable substitute components essential for system maintenance and replacement scenarios. The 0RLS225.X requires a compatible fuse holder for installation and operates within a breaking capacity of 10kA at rated voltage.

Substiute Parts

0RLS225.X

Littelfuse Inc.In Stock: 10710RLS225.X Datasheet

Current PartRFQ

KLSR225.X

Littelfuse Inc.In Stock: 824KLSR225.X Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 0RLS225.X is determined by the following critical parameters:

• Current Rating: 225A (must match exactly)
• Voltage Rating - AC: 600 VAC (must match or exceed)
• Fuse Type: Cartridge with cylindrical, blade terminal configuration
• Mounting: Requires compatible fuse holder
• Response Time: Fast Blow characteristic
• Physical dimensions and terminal compatibility

The KLSR225.X from Littelfuse Inc. meets these substitution criteria. While it belongs to a different fuse class (RK1 versus H) and offers enhanced specifications, it maintains electrical and mechanical compatibility with the 0RLS225.X in applications requiring 225A, 600 VAC protection.

Parameter Comparison

Engineering Selection Recommendations

The KLSR225.X is the manufacturer-recommended substitute for the obsolete 0RLS225.X. Both components share identical current and AC voltage ratings, matching fuse type, response characteristics, and terminal configuration. The KLSR225.X maintains active product status with current manufacturing support and holds equivalent regulatory approvals (CE, CSA, UL).

The KLSR225.X provides enhanced breaking capacity (200kA AC versus 10kA) and includes DC voltage capability (300 VDC), representing a performance upgrade while maintaining backward compatibility in 600 VAC, 225A applications. The KLSR225.X achieves ROHS3 compliance, whereas the 0RLS225.X does not.

Physical dimension differences exist: the KLSR225.X measures 2.594" Dia x 11.626" L (65.90mm x 295.30mm) compared to the 0RLS225.X at 2.594" Dia x 7.878" L (65.90mm x 200.10mm). Verification of holder compatibility is necessary prior to substitution.

Frequently Asked Questions (FAQ)

Q: Can the KLSR225.X directly replace the 0RLS225.X in existing installations?

A: The KLSR225.X matches the critical electrical parameters (225A, 600 VAC, fast-blow response, cylindrical blade terminals) required for substitution. However, the increased length (11.626" versus 7.878") requires confirmation that the existing fuse holder accommodates the longer cartridge. Mechanical fit must be verified before installation.

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

A: Class H and Class RK1 are distinct fuse classifications with different breaking capacities and application profiles. The 0RLS225.X is Class H with 10kA breaking capacity. The KLSR225.X is Class RK1 with 200kA AC breaking capacity. Both are fast-blow cartridge fuses rated for 225A at 600 VAC. Consult application requirements to determine if the higher breaking capacity of the RK1 class is acceptable or necessary.

Q: Does the KLSR225.X offer any additional capabilities?

A: The KLSR225.X includes 300 VDC voltage rating in addition to 600 VAC, enabling use in DC applications where the 0RLS225.X is not rated. The KLSR225.X also achieves ROHS3 compliance, whereas the 0RLS225.X does not.

Q: Are there inventory considerations for this substitution?

A: The 0RLS225.X (obsolete) has 962 pieces in stock. The KLSR225.X (active product) has 756 pieces in stock. As an active product, the KLSR225.X maintains ongoing manufacturing availability, whereas the 0RLS225.X will not be replenished.

Q: What certifications apply to both parts?

A: Both the 0RLS225.X and KLSR225.X hold CE, CSA, and UL approvals, ensuring regulatory compliance across major markets and applications.