5HT 6.3 Ceramic Fuse Equivalent & Substitute Parts

Part Overview

The 5HT 6.3 is a 6.3 A ceramic cartridge fuse rated for 250 V AC, manufactured by Bel Fuse Inc. in a 5mm x 20mm form factor with slow-blow response characteristics. The main part is classified as obsolete, making equivalent substitutes necessary for ongoing applications. Active alternatives from multiple manufacturers provide functionally compatible options while maintaining the same electrical ratings and mechanical dimensions.

Key Parameters

Parameter	Value
Current Rating	6.3 A
Voltage Rating (AC)	250 V
Package / Case	5mm x 20mm
Fuse Type	Cartridge, Ceramic
Response Time	Slow Blow
Breaking Capacity	1.5 kA @ Rated Voltage
Mounting Type	Requires Holder

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict alignment with the following parameters: current rating (6.3 A), AC voltage rating (250 V), package dimensions (5mm x 20mm), fuse type (ceramic cartridge), and response time (slow blow). All listed substitutes meet these core electrical and mechanical requirements.

The substitute parts are categorized as follows:

Direct Equivalent: 5HT 6.3-R (Bel Fuse Inc.) — identical specifications with active product status and improved RoHS3 compliance.

Compatible Substitutes: 0001.2512 (SCHURTER), 021506.3HXP (Littelfuse), and BK1/S505-6.3-R (Eaton) — all meet the primary electrical parameters with 1.5 kA breaking capacity and slow-blow response.

Similar Substitute: 0034.2524 (SCHURTER) — meets current and voltage ratings but differs in response time (medium blow) and breaking capacity (1 kA), requiring application verification.

Parameter Comparison

Parameter	5HT 6.3	5HT 6.3-R	0001.2512	0034.2524	021506.3HXP	BK1/S505-6.3-R
Manufacturer	Bel Fuse Inc.	Bel Fuse Inc.	SCHURTER Inc.	SCHURTER Inc.	Littelfuse Inc.	Eaton
Current Rating (A)	6.3	6.3	6.3	6.3	6.3	6.3
Voltage Rating AC (V)	250	250	250	250	250	250
Voltage Rating DC (V)	—	—	150	125	—	—
Package / Case	5mm x 20mm	5mm x 20mm	5mm x 20mm	5mm x 20mm	5mm x 20mm	5mm x 20mm
Response Time	Slow Blow	Slow Blow	Slow Blow	Medium Blow	Slow Blow	Slow Blow
Breaking Capacity @ Rated Voltage (kA)	1.5	1.5	1.5	1.0	1.5	1.5
Melting I²t	181	181	171	159	128.75	111
Operating Temperature Range (°C)	-55 to 125	-55 to 125	-55 to 125	-40 to 85	-55 to 125	—
Product Status	Obsolete	Active	Active	Active	Active	Active
RoHS Status	Non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant

Engineering Selection Recommendations

Primary Selection: 5HT 6.3-R (Bel Fuse Inc.) is the recommended direct replacement. It maintains identical electrical specifications and mechanical form factor while offering active product status and ROHS3 compliance. Inventory availability is substantial at 104,480 pieces.

Secondary Selections: 021506.3HXP (Littelfuse) and BK1/S505-6.3-R (Eaton) are functionally equivalent alternatives with 1.5 kA breaking capacity and slow-blow response. Both carry comprehensive international certifications (CCC, CE, CSA, UL, VDE) and ROHS3 compliance.

Conditional Selection: 0001.2512 (SCHURTER) is compatible for AC applications with DC voltage capability (150 V DC). It maintains 1.5 kA breaking capacity and slow-blow characteristics.

Limited Compatibility: 0034.2524 (SCHURTER) differs in response time (medium blow) and breaking capacity (1 kA). Selection requires confirmation that the application tolerates medium-blow response and lower fault current interruption capability.

Frequently Asked Questions (FAQ)

Q: Can 5HT 6.3-R be used as a direct replacement for 5HT 6.3?

A: Yes. Both parts share identical current rating (6.3 A), AC voltage rating (250 V), package dimensions (5mm x 20mm), response time (slow blow), and breaking capacity (1.5 kA). The primary difference is product status (active vs. obsolete) and RoHS compliance.

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

A: Melting I²t indicates the thermal energy required to melt the fuse element. Lower values indicate faster response to overcurrent. Substitutes with different I²t values may alter circuit protection timing. Verify application tolerance for thermal response variations.

Q: Are all substitutes mechanically compatible with existing fuse holders?

A: All listed substitutes maintain the 5mm x 20mm cartridge form factor and require the same holder type. Mechanical installation compatibility is confirmed across all alternatives.

Q: What certifications are critical for my application?

A: Certification requirements depend on end-use application and regional standards. All active substitutes carry multiple international certifications (CCC, CE, CSA, VDE). Verify specific certification requirements for your application before selection.

Q: Can 0034.2524 be used if the application requires 1.5 kA breaking capacity?

A: No. The 0034.2524 has a 1 kA breaking capacity, which is insufficient for applications requiring 1.5 kA fault current interruption. Select alternatives with matching 1.5 kA breaking capacity.

Q: Does DC voltage rating matter if my application is AC-only?

A: For AC-only applications, DC voltage rating is not a limiting factor. Parts with or without DC ratings are functionally equivalent in pure AC circuits.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message