JLLS040.T Equivalent & Substitute Parts

Part Overview

The JLLS040.T is a 40A cartridge fuse manufactured by Littelfuse Inc. under the POWR-GARD® JLLS series. This fast-blow fuse is rated for 600 VAC / 300 VDC operation and is designed for electrical and industrial applications requiring holder-mounted cartridge fuses. The part maintains active product status with 971 units in current inventory. Substitute parts are identified to provide alternative sourcing options when the primary part is unavailable or when procurement requirements necessitate qualified alternatives.

Substiute Parts

JLLS040.T

Littelfuse Inc.In Stock: 1069JLLS040.T Datasheet

Current PartRFQ

JJS-40

Eaton - Bussmann Electrical DivisionIn Stock: 764JJS-40 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the JLLS040.T is determined by the following critical parameters:

• Current Rating: 40A (exact match required)
• Voltage Rating - AC: 600 VAC (exact match required)
• Fuse Class: T (exact match required)
• Response Time: Fast Blow (exact match required)
• Fuse Type: Cartridge (exact match required)
• Mounting Type: Requires Holder (exact match required)
• Approval Agencies: CE, CSA, UL (minimum compliance required)
• Breaking Capacity: 200kA (exact match required)

The JJS-40 manufactured by Eaton - Bussmann Electrical Division qualifies as a substitute part. This part meets all critical electrical parameters including 40A current rating, 600 VAC voltage rating, Class T fuse classification, fast-blow response time, and 200kA breaking capacity. Both parts carry identical regulatory approvals (CE, CSA, UL) and RoHS3 compliance status. Physical dimensions vary slightly between the two cartridge designs, but both are non-standard cartridge form factors compatible with appropriate holder assemblies.

Parameter Comparison

Engineering Selection Recommendations

Both the JLLS040.T and JJS-40 are active products with full regulatory compliance (CE, CSA, UL certifications) and RoHS3 compliance status. Selection between these parts should be based on:

• Holder compatibility: Physical dimensions differ between the two cartridge designs. The JLLS040.T measures 1.000" diameter × 1.563" length, while the JJS-40 measures 0.810" diameter × 1.560" width. Verify that the selected fuse cartridge is compatible with the installed holder assembly.

• DC voltage requirement: The JLLS040.T is rated for 300 VDC operation. The JJS-40 specification does not include a DC voltage rating. For applications requiring DC voltage protection, the JLLS040.T is the specified choice.

• Inventory and lead time: Current inventory levels are 971 units for JLLS040.T and 714 units for JJS-40. Procurement decisions may be influenced by availability and delivery schedules.

Frequently Asked Questions (FAQ)

Q: Can the JJS-40 be used as a direct replacement for the JLLS040.T in all applications?

A: The JJS-40 is electrically equivalent for AC applications at 600 VAC, 40A with identical fast-blow response and breaking capacity. However, physical dimensions differ, requiring verification of holder compatibility. For DC applications, the JLLS040.T is specified at 300 VDC; the JJS-40 does not include a DC rating.

Q: What determines if a fuse can substitute for the JLLS040.T?

A: Substitute fuses must match the following parameters: 40A current rating, 600 VAC voltage rating, Class T fuse classification, fast-blow response time, 200kA breaking capacity, and cartridge form factor. Regulatory approvals (CE, CSA, UL) and RoHS3 compliance are required. Physical dimensions must be compatible with the holder assembly.

Q: Are there dimensional compatibility issues between JLLS040.T and JJS-40?

A: Yes. The JLLS040.T is 1.000" diameter × 1.563" length, while the JJS-40 is 0.810" diameter × 1.560" width. Both are non-standard cartridge form factors. Confirm that the fuse holder is designed to accept the specific cartridge dimensions before installation.

Q: Do both parts carry the same regulatory approvals?

A: Yes. Both the JLLS040.T and JJS-40 carry CE, CSA, and UL approvals and are ROHS3 compliant, meeting identical regulatory requirements for electrical and industrial applications.

Q: What is the difference in packaging between these parts?

A: The JLLS040.T is supplied in box packaging, while the JJS-40 is supplied in bulk packaging. Packaging format may affect procurement quantities and handling procedures but does not affect electrical or mechanical performance.