5HT 4 Ceramic Fuse Equivalent & Substitute Parts

Part Overview

The 5HT 4 is a 4 A, 250 V AC ceramic cartridge fuse manufactured by Bel Fuse Inc. in a 5mm x 20mm form factor with slow-blow response characteristics. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new design implementations. The fuse requires a compatible holder for installation and is approved across multiple international standards including UL, CE, CSA, and VDE.

Substiute Parts

5HT 4

Bel Fuse Inc.In Stock: 7845HT 4 Datasheet

Current PartRFQ

5HT 4-R

Bel Fuse Inc.In Stock: 95935HT 4-R Datasheet

DirectRFQ

0001.2510

SCHURTER Inc.In Stock: 165340001.2510 Datasheet

DirectRFQ

BK1/S505-4-R

Eaton - Electronics DivisionIn Stock: 1673BK1/S505-4-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 5HT 4 is determined by strict equivalence across the following parameters: current rating (4 A), AC voltage rating (250 V), fuse type (cartridge ceramic), physical package (5mm x 20mm), response time (slow blow), and breaking capacity (1.5 kA). All substitute parts must maintain these core electrical and mechanical specifications to ensure functional compatibility within the original circuit design.

The substitute parts are grouped as follows:

Direct Manufacturer Equivalents: Parts that match all primary electrical and mechanical parameters with identical or superior specifications.

Similar Functional Equivalents: Parts that meet all core substitution criteria but may have minor variations in secondary parameters such as melting I²t or DC cold resistance.

Parameter Comparison

Engineering Selection Recommendations

5HT 4-R (Bel Fuse Inc.): This is the primary direct replacement for the obsolete 5HT 4. It maintains identical electrical and mechanical specifications with the same manufacturer lineage. The 5HT 4-R carries active product status and is ROHS3 compliant, making it suitable for new designs and legacy system updates. Approval agencies include CCC, CE, CSA, cURus, IMQ, PSE, SEMKO, and VDE. Inventory availability is high at 9,552 pieces.

0001.2510 (SCHURTER Inc.): This substitute meets all core substitution criteria with identical current, AC voltage, package, and breaking capacity specifications. The SCHURTER part includes a 150 V DC rating, providing additional capability for dual-voltage applications. It is ROHS3 compliant and approved by CCC, cURus, KC, PSE/JET, and VDE. Melting I²t is 62.4, slightly higher than the original specification. Inventory availability is 16,466 pieces.

BK1/S505-4-R (Eaton - Electronics Division): This substitute provides functional equivalence across all primary electrical and mechanical parameters. The Eaton part carries the broadest approval agency coverage including BSI, CCC/CQC, CSA, cURus, IMQ, KC, PSE/JET, SEMKO, and VDE. It is ROHS3 compliant with MSL rating of 1 (Unlimited). The melting I²t is 38.45, lower than the original specification. Inventory availability is 1,573 pieces.

Frequently Asked Questions (FAQ)

Q: Can the 5HT 4-R directly replace the obsolete 5HT 4?

A: Yes. The 5HT 4-R is manufactured by the same company (Bel Fuse Inc.) and maintains identical electrical specifications (4 A, 250 V AC), fuse type (cartridge ceramic), package dimensions (5mm x 20mm), response time (slow blow), and breaking capacity (1.5 kA). It is the recommended direct replacement.

Q: What is the difference between the SCHURTER 0001.2510 and the original 5HT 4?

A: The 0001.2510 meets all core substitution requirements with matching current, AC voltage, package, and breaking capacity. The primary difference is the addition of a 150 V DC rating and a slightly higher melting I²t value (62.4 versus 56). Both are ceramic cartridge fuses in the 5mm x 20mm form factor.

Q: Are all substitute parts RoHS compliant?

A: The original 5HT 4 is RoHS non-compliant. All three substitute parts (5HT 4-R, 0001.2510, and BK1/S505-4-R) are ROHS3 compliant, making them suitable for applications requiring RoHS compliance.

Q: What is the significance of melting I²t values in fuse selection?

A: Melting I²t indicates the thermal energy required to melt the fuse element. The original 5HT 4 has a melting I²t of 56. The SCHURTER 0001.2510 (62.4) will require slightly more thermal energy to operate, while the Eaton BK1/S505-4-R (38.45) will respond more quickly. Selection depends on circuit protection requirements and inrush current characteristics.

Q: Do all substitute parts require the same holder as the original 5HT 4?

A: All substitute parts are ceramic cartridge fuses in the 5mm x 20mm package and require a compatible 5mm x 20mm fuse holder. Verify holder compatibility with the specific fuse holder model in your application.

Q: Which substitute part has the best availability?

A: The SCHURTER 0001.2510 has the highest inventory availability at 16,466 pieces, followed by the Bel Fuse 5HT 4-R at 9,552 pieces, and the Eaton BK1/S505-4-R at 1,573 pieces.

Q: Can the BK1/S505-4-R be used in applications requiring the original 5HT 4 specifications?

A: Yes. The BK1/S505-4-R meets all core electrical and mechanical substitution criteria. However, note that its melting I²t (38.45) is lower than the original (56), meaning it will respond faster to thermal stress. Verify that this faster response time is compatible with your circuit's inrush current profile and protection strategy.