5SF 250 Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The 5SF 250 is a 250 mA, 250 V AC/DC fast-blow glass cartridge fuse manufactured by Bel Fuse Inc. in a 5mm x 20mm form factor. This component is classified as obsolete, requiring identification of active equivalent alternatives for new designs and ongoing maintenance applications. Substitute parts must maintain identical electrical ratings, mechanical dimensions, and holder compatibility to ensure direct circuit board replacement without modification.

Substiute Parts

5SF 250

Bel Fuse Inc.In Stock: 10505SF 250 Datasheet

Current PartRFQ

0034.1510

SCHURTER Inc.In Stock: 13910034.1510 Datasheet

DirectRFQ

0217.250MXBP

Littelfuse Inc.In Stock: 8260217.250MXBP Datasheet

DirectRFQ

0217.250MXP

Littelfuse Inc.In Stock: 20280217.250MXP Datasheet

DirectRFQ

0217.250TXP

Littelfuse Inc.In Stock: 11350217.250TXP Datasheet

DirectRFQ

0217.250VXP

Littelfuse Inc.In Stock: 11720217.250VXP Datasheet

DirectRFQ

0217.250HXP

Littelfuse Inc.In Stock: 22550217.250HXP Datasheet

SimilarRFQ

0235.250HXP

Littelfuse Inc.In Stock: 13960235.250HXP Datasheet

SimilarRFQ

S500-250-R

Eaton - Electronics DivisionIn Stock: 905S500-250-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict equivalence across the following parameters:

• Current Rating: 250 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Response Time: Fast Blow (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Breaking Capacity: 35A (exact match required)
• Operating Temperature: -55°C ~ 125°C (exact match required)

All substitute parts listed below meet these criteria and are compatible with existing 5SF 250 holder assemblies. Substitutes are grouped by manufacturer and product status (active vs. obsolete).

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts are active products with current manufacturing support, eliminating obsolescence risk associated with the 5SF 250. Selection among substitutes should prioritize the following criteria:

RoHS Compliance: All substitute parts are ROHS3 compliant, meeting current environmental regulations. The original 5SF 250 is RoHS non-compliant and unsuitable for new designs subject to RoHS requirements.

Certification Coverage: Littelfuse 217 series parts (0217.250MXBP, 0217.250MXP, 0217.250TXP, 0217.250VXP, 0217.250HXP) carry the broadest approval agency coverage, including CCC, CE, CSA, K-MARK, SEMKO, UL, and VDE. SCHURTER 0034.1510 carries CCC, cURus, and VDE certifications. Eaton S500-250-R carries BSI, CCC, CSA, cURus, IMQ, SEMKO, and VDE certifications.

Inventory Availability: Littelfuse 0217.250HXP offers the highest stock level (2215 units), followed by 0217.250MXP (1963 units), providing supply chain continuity for high-volume applications.

Melting I²t Characteristics: Littelfuse 217 series and SCHURTER 0034.1510 exhibit lower melting I²t values (0.04 and 0.0159 respectively) compared to the original 5SF 250 (0.05), indicating faster thermal response. Eaton S500-250-R exhibits significantly higher melting I²t (0.28), suitable for applications requiring extended thermal tolerance.

Frequently Asked Questions (FAQ)

Q: Can I use any of these substitute parts as a direct replacement for the 5SF 250?

A: Yes. All listed substitute parts meet the mandatory electrical and mechanical parameters: 250 mA current rating, 250 V AC voltage rating, fast-blow response, 5mm x 20mm package, and 35A breaking capacity. They are mechanically and electrically compatible with existing 5SF 250 holder assemblies.

Q: What is the difference between the Littelfuse 217 series variants (0217.250MXBP, 0217.250MXP, 0217.250TXP, 0217.250VXP, 0217.250HXP)?

A: All five Littelfuse 217 series parts share identical electrical ratings, breaking capacity, melting I²t (0.04), DC cold resistance (1.2325 Ω), operating temperature range (-55°C ~ 125°C), and RoHS3 compliance. The part number suffixes (MXBP, MXP, TXP, VXP, HXP) indicate internal design or packaging variations that do not affect electrical or mechanical compatibility. Selection among these variants should be based on availability and certification requirements for your specific application.

Q: How do the melting I²t values affect fuse selection?

A: Melting I²t determines the thermal energy required to melt the fuse element. Lower values indicate faster thermal response to overcurrent conditions. Littelfuse 217 series parts (0.04) and SCHURTER 0034.1510 (0.0159) respond faster than the original 5SF 250 (0.05). Eaton S500-250-R (0.28) provides extended thermal tolerance. Selection should match the thermal protection requirements of your circuit design.

Q: Are there differences in DC cold resistance among the substitutes?

A: Yes. DC cold resistance varies: Littelfuse 217 series and SCHURTER 0034.1510 range from 1.2325 to 1.3 Ω, while 0235.250HXP exhibits 2.25 Ω, and Eaton S500-250-R exhibits 4.3 Ω. Higher resistance increases voltage drop across the fuse during normal operation. For applications sensitive to voltage drop, select parts with lower DC cold resistance (Littelfuse 217 series or SCHURTER 0034.1510).

Q: Which substitute offers the best certification coverage?

A: Littelfuse 0217.250HXP and 0217.250MXP carry the broadest certification portfolio: CCC, CE, CSA, K-MARK, SEMKO, UL, and VDE. These certifications cover North American (UL, CSA), European (CE, VDE), and international markets (CCC, SEMKO, K-MARK).

Q: Is the 5SF 250 still available for purchase?

A: The 5SF 250 is classified as obsolete. Current inventory (961 units) is limited to existing stock. For new designs and long-term supply assurance, transition to an active substitute part such as Littelfuse 217 series or SCHURTER 0034.1510.