A6T40 Equivalent & Substitute Parts Reference

Part Overview

The A6T40 is a Class T fast-acting fuse manufactured by Mersen USA Newburyport-MA L.L.C. with a 40-ampere current rating and 200kA breaking capacity at rated voltage. This component is designed for electrical and industrial applications requiring fast-blow response characteristics. The part is currently active in production with 992 units in stock. Due to supply chain considerations, manufacturing availability, or application-specific requirements, equivalent substitute parts may be necessary for procurement or system design purposes.

Substiute Parts

A6T40

Mersen USA Newburyport-MA L.L.C.In Stock: 1062A6T40 Datasheet

Current PartRFQ

JJS-40

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

SimilarRFQ

JLLS040.T

Littelfuse Inc.In Stock: 1069JLLS040.T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the A6T40 are qualified based on the following critical parameters that determine functional equivalence:

• Current Rating: 40 amperes
• Voltage Rating - AC: 600 VAC minimum
• Fuse Class: T (fast-acting)
• Breaking Capacity: 200kA at rated voltage
• Fuse Type: Cartridge configuration requiring holder
• Response Time: Fast Blow characteristic

The substitute parts JJS-40 and JLLS040.T meet all mandatory electrical and mechanical parameters required for direct substitution in applications designed for the A6T40. Both alternatives maintain identical current ratings, voltage specifications, breaking capacity, and fast-blow response characteristics.

Parameter Comparison

Engineering Selection Recommendations

All three parts maintain active product status and are suitable for electrical and industrial applications. The JJS-40 (Eaton - Bussmann Electrical Division, Limitron™ JJS series) and JLLS040.T (Littelfuse Inc., POWR-GARD® JLLS series) are both ROHS3 compliant and carry CE, CSA, and UL approvals. The A6T40 is RoHS non-compliant. Selection between substitute parts should be based on application voltage requirements, holder compatibility, and physical dimensions. The JLLS040.T provides additional DC voltage rating capability (300 VDC) for applications requiring dual-voltage operation.

Frequently Asked Questions (FAQ)

Q: Can JJS-40 and JLLS040.T be used interchangeably with A6T40?

A: Both substitute parts meet the core electrical parameters (40A, 600 VAC, Class T, 200kA breaking capacity, fast-blow response). Physical dimensions differ slightly, requiring verification of holder compatibility before installation.

Q: What is the primary difference between JJS-40 and JLLS040.T?

A: The JLLS040.T includes a 300 VDC voltage rating in addition to 600 VAC, making it suitable for dual-voltage applications. Physical dimensions also differ: JJS-40 is 0.810" Dia x 1.560" W, while JLLS040.T is 1.000" Dia x 1.563" L.

Q: Are there compliance differences between the A6T40 and its substitutes?

A: The A6T40 is RoHS non-compliant. Both JJS-40 and JLLS040.T are ROHS3 compliant and carry CE, CSA, and UL approvals. Applications requiring RoHS compliance should specify JJS-40 or JLLS040.T.

Q: Do substitute parts require the same holder as A6T40?

A: All three parts are cartridge-type fuses requiring a holder. Physical dimensions vary between manufacturers, necessitating holder compatibility verification before substitution.

Q: What applications are these fuses designed for?

A: These Class T fast-acting fuses are designed for electrical and industrial applications requiring fast-blow protection characteristics at 40-ampere ratings and 600 VAC operation.