5TT 4 Equivalent & Substitute Parts

Part Overview

The 5TT 4 is a 4A 125VAC slow-blow glass cartridge fuse manufactured by Bel Fuse Inc., designed for 5mm x 20mm holder applications. This component is classified as obsolete, making identification of active equivalent parts essential for ongoing system maintenance and component procurement. The substitute part 5TT 4-R maintains identical electrical and mechanical specifications while offering active product status and improved compliance characteristics.

Substiute Parts

5TT 4

Bel Fuse Inc.In Stock: 8375TT 4 Datasheet

Current PartRFQ

5TT 4-R

Bel Fuse Inc.In Stock: 26135TT 4-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 5TT 4-R qualifies as a direct substitute for the 5TT 4 based on the following critical parameters:

• Current Rating: Identical at 4 A
• Voltage Rating (AC): Identical at 125 V
• Fuse Type: Both are Cartridge, Glass construction
• Response Time: Both are Slow Blow
• Package / Case: Both are 5mm x 20mm
• Breaking Capacity @ Rated Voltage: Identical at 10kA
• Melting I²t: Identical at 103
• Operating Temperature Range: Identical at -55°C ~ 125°C
• Mounting Type: Both require holder mounting

The substitution is valid because all electrical and mechanical parameters that determine fuse functionality and compatibility remain unchanged between the main part and substitute.

Parameter Comparison

Engineering Selection Recommendations

The 5TT 4-R is the appropriate selection for applications currently using the 5TT 4. The substitute part maintains full electrical and mechanical compatibility while offering the following advantages:

• Active product status ensures ongoing availability and supply chain continuity
• ROHS3 compliance aligns with current environmental and regulatory requirements
• Identical electrical performance and breaking capacity guarantee functional equivalence
• Maintained certifications (CE, CSA, PSE) confirm regulatory acceptance
• Marginally improved DC cold resistance (0.029 Ohms vs. 0.03 Ohms) presents no functional impact

Frequently Asked Questions (FAQ)

Q: Can the 5TT 4-R be used as a direct replacement for the 5TT 4?

A: Yes. The 5TT 4-R is electrically and mechanically identical to the 5TT 4 across all critical parameters including current rating, voltage rating, fuse type, response time, package dimensions, and breaking capacity.

Q: What is the difference between the 5TT 4 and 5TT 4-R?

A: The primary differences are product status (5TT 4 is obsolete; 5TT 4-R is active), RoHS compliance (5TT 4 is non-compliant; 5TT 4-R is ROHS3 compliant), and DC cold resistance (5TT 4 is 0.03 Ohms; 5TT 4-R is 0.029 Ohms). All electrical and mechanical specifications remain identical.

Q: Will the 5TT 4-R fit in existing 5TT 4 holders?

A: Yes. Both parts share identical 5mm x 20mm package dimensions and require the same holder mounting configuration.

Q: Are the certifications the same for both parts?

A: Yes. Both the 5TT 4 and 5TT 4-R carry CE, CSA, and PSE approvals.

Q: Why should I choose the 5TT 4-R over the 5TT 4?

A: The 5TT 4-R is the active product with current manufacturing support, ROHS3 compliance, and guaranteed supply availability. The 5TT 4 is obsolete and subject to supply discontinuation.