TPS-40LB Equivalent & Substitute Parts

Part Overview

The TPS-40LB is a 40A 170 VDC fuse cartridge manufactured by Eaton - Bussmann Electrical Division, part of the Telpower® TPS series. This component is designed for bolt mount applications in telecom systems with a cylindrical blade terminal configuration. The part is currently obsolete, making equivalent substitutes necessary for ongoing maintenance and system support in legacy telecom installations.

Substiute Parts

TPS-40LB

Eaton - Bussmann Electrical DivisionIn Stock: 999TPS-40LB Datasheet

Current PartRFQ

0TLS040.TXL

Littelfuse Inc.In Stock: 10260TLS040.TXL Datasheet

SimilarRFQ

0TLS040.TXLB

Littelfuse Inc.In Stock: 7500TLS040.TXLB Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the TPS-40LB is determined by strict equivalence across the following critical parameters:

• Current Rating: 40A (exact match required)
• Voltage Rating: 170 VDC (exact match required)
• Fuse Type: Cartridge (exact match required)
• Mounting Type: Bolt Mount (exact match required)
• Package / Case: Cylindrical, Blade Terminal (Bolt) (exact match required)
• Breaking Capacity: 100kA (exact match required)

The two substitute parts identified—0TLS040.TXL and 0TLS040.TXLB from Littelfuse Inc.—meet all critical electrical and mechanical parameters. Both are manufactured by Littelfuse as part of the POWR-GARD® TLS series and maintain full compatibility with the original TPS-40LB specification for telecom applications.

Parameter Comparison

Engineering Selection Recommendations

Both Littelfuse substitutes (0TLS040.TXL and 0TLS040.TXLB) are active products with current manufacturing support, providing supply continuity for the obsolete TPS-40LB. Both carry CE and cURus certifications, meeting regulatory requirements for telecom applications. The Littelfuse parts are ROHS3 compliant, offering environmental compliance advantages over the original part.

The primary distinction between the two Littelfuse options is physical length: 0TLS040.TXL measures 1.740" (44.20mm) while 0TLS040.TXLB measures 1.580" (40.13mm). Both maintain the same 0.563" (14.30mm) diameter and identical electrical specifications. Selection between these two should be based on available mounting space within the equipment housing, as both are electrically and functionally equivalent for the TPS-40LB application.

Frequently Asked Questions (FAQ)

Q: Can 0TLS040.TXL and 0TLS040.TXLB be used interchangeably with TPS-40LB?

A: Both Littelfuse parts meet all critical electrical parameters (40A, 170 VDC, 100kA breaking capacity) and mounting requirements (bolt mount, cylindrical blade terminal). Selection depends on physical space constraints, as the two Littelfuse variants differ in length.

Q: What is the significance of the length difference between 0TLS040.TXL and 0TLS040.TXLB?

A: The TPS-40LB measures 0.874" in length, while 0TLS040.TXL is 1.740" and 0TLS040.TXLB is 1.580". Both substitute parts are longer than the original. Verify mounting clearance in your equipment before selection.

Q: Are the Littelfuse substitutes certified for telecom applications?

A: Both 0TLS040.TXL and 0TLS040.TXLB carry CE and cURus certifications, meeting regulatory standards for telecom use. Both are ROHS3 compliant.

Q: Why is the TPS-40LB obsolete?

A: The TPS-40LB is listed as obsolete by the manufacturer. The active Littelfuse POWR-GARD® TLS series provides current manufacturing support and supply availability for equivalent 40A 170 VDC cartridge fuse applications.

Q: Do the substitute parts have the same response time as the original?

A: The TPS-40LB response time is not specified in available documentation. Both Littelfuse substitutes are rated as Fast Blow, which is standard for this fuse category.