Littelfuse 0461.500ERT Equivalent & Substitute Parts

Part Overview

The Littelfuse 0461.500ERT is a 500mA, 250VAC board mount surface mount fuse from the Nano²® Telelink® 461 series, designed for telecom applications. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new designs. The fuse features slow blow response characteristics with a 50A breaking capacity at rated voltage and operates across a temperature range of -55°C to 125°C.

Substiute Parts

0461.500ERT

Littelfuse Inc.In Stock: 20920461.500ERT Datasheet

Current PartRFQ

0461.500ER

Littelfuse Inc.In Stock: 198420461.500ER Datasheet

DirectRFQ

TR2/TCP500-R

Eaton - Electronics DivisionIn Stock: 7913TR2/TCP500-R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0461.500ERT are identified based on the following critical parameters that determine functional equivalence:

Primary Matching Criteria:

• Current Rating: 500mA (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Fuse Type: Board Mount (exact match required)
• Package / Case: 2-SMD, Square End Block (exact match required)

Secondary Compatibility Parameters:

• Voltage Rating - AC: 250VAC minimum (equal or higher acceptable)
• Response Time: Slow Blow (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)
• Breaking Capacity: 50A minimum at rated voltage

Two substitute parts meet these criteria:

1. 0461.500ER (Littelfuse Inc.) - Direct manufacturer alternative with enhanced voltage rating (600VAC/80VDC) and higher breaking capacity (60A AC, 100A DC). Maintains identical current rating, package, and response characteristics. Product status is active with improved RoHS3 compliance.

2. TR2/TCP500-R (Eaton - Electronics Division) - Cross-manufacturer equivalent from the TCP series. Matches all primary criteria with identical current rating, mounting type, and package configuration. Maintains 250VAC voltage rating and 50A breaking capacity. Product status is active with RoHS compliance.

Parameter Comparison

Engineering Selection Recommendations

0461.500ER (Littelfuse Inc.) is the primary substitute for the obsolete 0461.500ERT. Both parts are manufactured by Littelfuse and share identical mechanical dimensions, current rating, and response characteristics. The 0461.500ER provides enhanced voltage ratings (600VAC/80VDC versus 250VAC) and higher breaking capacity (60A AC, 100A DC versus 50A), making it suitable for applications requiring greater electrical stress tolerance. The part is active in production with ROHS3 compliance, addressing regulatory requirements that the original obsolete part does not meet.

TR2/TCP500-R (Eaton - Electronics Division) serves as a cross-manufacturer equivalent. This part maintains the exact current rating, voltage rating, and breaking capacity specifications of the original 0461.500ERT. Physical dimensions show minor variation (0.405" L x 0.109" W x 0.109" H versus 0.398" L x 0.123" W x 0.123" H), which may require PCB layout verification. The part is active in production with RoHS compliance and carries identical CSA and UR approvals. The melting I²t value of 1.3 differs from the original specification of 0.84, which may affect thermal response characteristics in specific circuit applications.

Both substitutes maintain the required 2-SMD, Square End Block package configuration and surface mount capability for direct board integration. Selection between these options depends on voltage margin requirements, thermal response characteristics, and supply chain considerations.

Frequently Asked Questions (FAQ)

Q: Can the 0461.500ER directly replace the 0461.500ERT in existing designs?

A: Yes. The 0461.500ER maintains identical current rating (500mA), mounting type (surface mount), package configuration (2-SMD, Square End Block), and mechanical dimensions (10.10mm x 3.12mm x 3.12mm). The enhanced voltage rating (600VAC versus 250VAC) and higher breaking capacity (60A AC versus 50A) provide additional electrical margin without compromising compatibility. Both parts carry CSA and UR approvals and operate across the same temperature range (-55°C to 125°C).

Q: What are the key differences between the 0461.500ER and TR2/TCP500-R substitutes?

A: Both parts match the original 0461.500ERT in current rating, voltage rating, and breaking capacity. The primary differences are: (1) Manufacturer - Littelfuse versus Eaton; (2) Physical dimensions - the Eaton part is slightly smaller (10.29mm x 2.77mm x 2.77mm versus 10.10mm x 3.12mm x 3.12mm), requiring PCB layout verification; (3) Melting I²t - the Eaton part specifies 1.3 versus 0.84 for both Littelfuse parts, affecting thermal response time; (4) DC Cold Resistance - 0.53 Ohms (Eaton) versus 0.56 Ohms (Littelfuse).

Q: Is the TR2/TCP500-R suitable for applications requiring specific thermal response characteristics?

A: The TR2/TCP500-R has a melting I²t value of 1.3, compared to 0.84 for the original 0461.500ERT and 0461.500ER. This difference indicates slower thermal response. Applications requiring precise thermal protection characteristics matching the original specification should use the 0461.500ER. The TR2/TCP500-R is suitable for applications where thermal response margin is acceptable or where the higher I²t value provides beneficial protection.

Q: Are there packaging differences that affect board assembly?

A: The 0461.500ER and original 0461.500ERT share identical dimensions (10.10mm x 3.12mm x 3.12mm) and packaging (2-SMD, Square End Block), requiring no PCB modifications. The TR2/TCP500-R has slightly different dimensions (10.29mm x 2.77mm x 2.77mm). While the package type remains 2-SMD, Square End Block, the dimensional variation requires verification against PCB footprint specifications before implementation.

Q: What compliance advantages do the substitute parts offer?

A: The original 0461.500ERT is RoHS non-compliant. The 0461.500ER is ROHS3 compliant, and the TR2/TCP500-R is RoHS compliant, both meeting current regulatory requirements. Both substitutes maintain CSA and UR approvals matching the original part. For applications subject to RoHS regulations, either substitute provides compliant alternatives to the obsolete original part.

Q: Can the 0461.500ER be used in applications rated for 250VAC if the circuit design only requires 250VAC operation?

A: Yes. The 0461.500ER is rated for 600VAC, which exceeds the 250VAC requirement. Using a part with higher voltage rating in a lower-voltage application does not compromise functionality or safety. The part will operate correctly at 250VAC with additional voltage margin, which is an acceptable engineering practice.