Bel Fuse Inc. 5MFP 2.5-R Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The 5MFP 2.5-R is a 2.5 A, 250 V AC/DC fast-blow glass cartridge fuse manufactured by Bel Fuse Inc. in a 5mm x 20mm through-hole axial package. The part is active in production with 1977 units currently in stock. Finding equivalent and substitute parts is necessary to ensure design flexibility, manage supply chain continuity, and maintain component availability across manufacturing cycles.

Substiute Parts

5MFP 2.5-R

Bel Fuse Inc.In Stock: 20705MFP 2.5-R Datasheet

Current PartRFQ

5SFP 2.5-R

Bel Fuse Inc.In Stock: 25095SFP 2.5-R Datasheet

Parametric EquivalentRFQ

021702.5MXEP

Littelfuse Inc.In Stock: 2287021702.5MXEP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 5MFP 2.5-R is determined by the following critical parameters:

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

All identified substitute parts meet these core electrical and mechanical parameters. Variations in breaking capacity, melting I²t, DC cold resistance, and approval agency certifications do not preclude substitution but may affect application-specific performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts are active products with full RoHS3 compliance and meet all core electrical and mechanical requirements for direct substitution with the 5MFP 2.5-R.

The 5SFP 2.5-R (Bel Fuse Inc.) is a parametric equivalent from the same manufacturer. It maintains identical current, voltage, package, and response characteristics. The 5SFP series offers expanded approval agency certifications (CCC, CE, CSA, cULus, IMQ, SEMKO, VDE) compared to the 5MFP series (CE, CSA, cULus, PSE). The 5SFP 2.5-R has lower DC cold resistance (0.026 Ohms vs. 0.039 Ohms) and higher melting I²t (10 vs. 7.6), with reduced breaking capacity (35 A vs. 200 A).

The 021702.5MXEP (Littelfuse Inc., Series 217) is a similar part from an alternative manufacturer. It meets all core substitution criteria with identical current, voltage, package, and response characteristics. This part carries the broadest approval agency coverage (BSI, CE, CCC, CSA, KC, PSE, SEMKO, UR, VDE). Physical dimensions show minor variation (0.228" Dia x 0.886" L vs. 0.217" Dia x 0.827" L), which remains within standard through-hole PCB footprint tolerances. DC cold resistance is 0.0334 Ohms with melting I²t of 9.46.

Frequently Asked Questions (FAQ)

Q: Can the 5SFP 2.5-R replace the 5MFP 2.5-R in existing designs?

A: Yes. Both parts share identical current rating (2.5 A), voltage rating (250 V AC), fuse type (cartridge glass), response time (fast blow), package dimensions (5mm x 20mm axial), and mounting type (through hole). The 5SFP 2.5-R is a direct parametric equivalent suitable for PCB and circuit board applications without design modification.

Q: What are the differences between the Bel Fuse 5MFP and 5SFP series?

A: The primary differences are breaking capacity (5MFP: 200 A vs. 5SFP: 35 A), DC cold resistance (5MFP: 0.039 Ohms vs. 5SFP: 0.026 Ohms), melting I²t (5MFP: 7.6 vs. 5SFP: 10), and approval agency certifications. Both series are fast-blow glass cartridge fuses with identical electrical ratings and package specifications.

Q: Can the Littelfuse 021702.5MXEP be used as a substitute for the Bel Fuse 5MFP 2.5-R?

A: Yes. The 021702.5MXEP meets all core electrical and mechanical requirements: 2.5 A current rating, 250 V AC voltage rating, fast-blow response, glass cartridge type, and 5mm x 20mm through-hole package. Minor physical dimension variations (0.228" Dia x 0.886" L) remain within standard PCB footprint tolerances for axial through-hole components.

Q: Are there any compliance or certification differences between these parts?

A: Yes. The 5MFP 2.5-R carries CE, CSA, cULus, and PSE certifications. The 5SFP 2.5-R adds CCC, IMQ, SEMKO, and VDE certifications. The 021702.5MXEP carries the broadest certification set: BSI, CE, CCC, CSA, KC, PSE, SEMKO, UR, and VDE. All three parts are ROHS3 compliant and REACH unaffected.

Q: Do these fuses have different thermal or electrical performance characteristics?

A: Yes. The 5MFP 2.5-R has the highest breaking capacity (200 A) and lowest melting I²t (7.6). The 5SFP 2.5-R and 021702.5MXEP have lower breaking capacities (35 A each) with higher melting I²t values (10 and 9.46 respectively). DC cold resistance also varies: 5MFP (0.039 Ohms), 5SFP (0.026 Ohms), and 021702.5MXEP (0.0334 Ohms). These differences may affect performance in high-current or high-temperature applications.

Q: Can these parts be used interchangeably in production?

A: All three parts are active products with current inventory availability. Interchangeability depends on application-specific requirements for breaking capacity, thermal characteristics, and required certifications. Verify that the selected substitute meets all regulatory and performance requirements for your specific application.