Equivalent & Substitute Parts for 5TT 2.5

Part Overview

The 5TT 2.5 is a 2.5 A, 250 V AC/DC glass cartridge fuse with a 5mm x 20mm form factor, manufactured by Bel Fuse Inc. This component is classified as obsolete, necessitating identification of active equivalent and substitute parts for ongoing system support and new designs. The fuse operates with slow-blow response characteristics and requires a compatible holder for installation.

Substiute Parts

5TT 2.5

Bel Fuse Inc.In Stock: 10355TT 2.5 Datasheet

Current PartRFQ

5TT 2.5-R

Bel Fuse Inc.In Stock: 26365TT 2.5-R Datasheet

DirectRFQ

5ET 2.5-R

Bel Fuse Inc.In Stock: 14615ET 2.5-R Datasheet

Parametric EquivalentRFQ

5ST 2.5-R

Bel Fuse Inc.In Stock: 60485ST 2.5-R Datasheet

Parametric EquivalentRFQ

021802.5HXP

LittelfuseIn Stock: 21320021802.5HXP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 5TT 2.5 is determined by strict equivalence across the following parameters:

• Current Rating: 2.5 A (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Slow Blow (exact match required)
• Mounting Type: Requires Holder (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)

All identified substitutes meet these core electrical and mechanical parameters. Variations in breaking capacity, melting I²t, DC cold resistance, and approval agencies are secondary characteristics that do not affect functional interchangeability within the specified parameter set.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the obsolete 5TT 2.5, the following selection criteria apply:

Direct Replacement (Bel Fuse Inc. Series): The 5TT 2.5-R is the active equivalent from the same manufacturer and series, offering identical electrical characteristics with improved RoHS3 compliance. This part maintains the same breaking capacity (100 A) and melting I²t (45) as the original.

Alternative Bel Fuse Inc. Options: The 5ET 2.5-R and 5ST 2.5-R are parametrically equivalent alternatives from Bel Fuse Inc. with different breaking capacities and melting I²t values. Selection between these variants depends on system-level breaking capacity requirements.

Cross-Manufacturer Alternative: The Littelfuse 021802.5HXP provides functional equivalence with broader approval agency coverage (CCC, CE, CSA, K-MARK, PSE, SEMKO, UL, VDE) and is available in higher inventory quantities. Dimensional tolerance variation (5.20mm diameter versus 5.10mm) must be evaluated for holder compatibility.

All substitute parts maintain RoHS3 compliance and REACH unaffected status, supporting modern regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the 5TT 2.5-R be used as a direct replacement for the 5TT 2.5?

A: Yes. The 5TT 2.5-R is the active equivalent from Bel Fuse Inc., maintaining identical current rating (2.5 A), voltage rating (250 V AC), package dimensions (5mm x 20mm), response time (slow blow), and operating temperature range (-55°C ~ 125°C). The primary difference is product status (active versus obsolete) and RoHS compliance improvement.

Q: What is the difference between the 5TT 2.5-R, 5ET 2.5-R, and 5ST 2.5-R?

A: All three parts share identical electrical ratings (2.5 A, 250 V AC) and package dimensions. They differ in breaking capacity and melting I²t: 5TT 2.5-R (100 A / 45), 5ET 2.5-R (150 A / 137), and 5ST 2.5-R (35 A / 20). Selection depends on the system's short-circuit current rating and protection requirements.

Q: Is the Littelfuse 021802.5HXP compatible with holders designed for the 5TT 2.5?

A: The 021802.5HXP has a nominal diameter of 5.20mm compared to the 5TT 2.5 at 5.10mm. Holder compatibility must be verified, as dimensional tolerance stacking may affect fit. Consult holder specifications and perform mechanical validation before deployment.

Q: Are all substitute parts RoHS compliant?

A: The 5TT 2.5 is RoHS non-compliant. All identified substitutes (5TT 2.5-R, 5ET 2.5-R, 5ST 2.5-R, and 021802.5HXP) are ROHS3 compliant, supporting modern regulatory requirements.

Q: Which substitute part has the highest inventory availability?

A: The Littelfuse 021802.5HXP has the highest inventory level at 21,272 pieces. Among Bel Fuse Inc. options, the 5ST 2.5-R has 6,019 pieces in stock.