BK/S501-V-2.5-R Ceramic Fuse Equivalent & Substitute Parts

Part Overview

The BK/S501-V-2.5-R is a ceramic cartridge fuse manufactured by Eaton - Electronics Division, rated at 2.5A, 250VAC, with a 5mm x 20mm form factor. This fast-blow fuse is designed for through-hole mounting applications requiring overcurrent protection in AC/DC circuits. The part maintains active product status with 871 units in current inventory. Substitute parts are identified when equivalent electrical ratings, mechanical dimensions, and approval certifications align with the original specification, enabling direct replacement in circuit protection applications.

Substiute Parts

BK/S501-V-2.5-R

Eaton - Electronics DivisionIn Stock: 914BK/S501-V-2.5-R Datasheet

Current PartRFQ

021602.5MXEP

Littelfuse Inc.In Stock: 1749021602.5MXEP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/S501-V-2.5-R is determined by strict alignment of the following parameters:

Mandatory Matching Parameters:

• Current Rating: 2.5 A (exact match required)
• Voltage Rating - AC: 250 V (minimum requirement)
• Fuse Type: Cartridge, Ceramic (construction type)
• Package / Case: 5mm x 20mm (Axial) (mechanical compatibility)
• Response Time: Fast Blow (protection characteristic)
• Breaking Capacity @ Rated Voltage: 1.5kA (fault interruption capability)
• Mounting Type: Through Hole (assembly compatibility)

Acceptable Variation Parameters:

• Melting I²t: Minor variations permitted within thermal response envelope
• DC Cold Resistance: Acceptable within normal manufacturing tolerance
• Physical Dimensions: Dimensional tolerance acceptable if fits standard 5x20mm fuse holder
• Operating Temperature Range: Extended ranges acceptable if minimum requirements met
• Approval Agencies: Substitute must hold certifications applicable to target market

The identified substitute part 021602.5MXEP (Littelfuse Inc., Series 216) satisfies all mandatory matching parameters and maintains compatibility with the original application requirements.

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: BK/S501-V-2.5-R (Eaton)

Use the original Eaton part when:

• Existing inventory supports continuous supply requirements
• Design documentation specifies Eaton components
• All target market certifications (BSI, cULus, IMQ, MITI/JET) are required
• Melting I²t specification of 3.9 is critical to circuit protection timing

Substitute Selection: 021602.5MXEP (Littelfuse)

Use the Littelfuse substitute when:

• Eaton part availability is constrained
• Target markets require certifications held by Littelfuse (UL, KC, PSE, CE)
• Operating temperature range of -55°C to 125°C meets application requirements
• Lower melting I²t value (2.695) is acceptable for faster thermal response
• Inventory availability (1666 units) supports project timelines
• Dimensional tolerance of 5.80mm diameter and 22.50mm length fits fuse holder design

Both parts maintain identical electrical ratings (2.5A, 250VAC), fast-blow response, 1.5kA breaking capacity, and through-hole mounting compatibility. Selection between them is based on supply chain, regulatory certification requirements, and thermal response characteristics specific to the application.

Frequently Asked Questions (FAQ)

Q: Can 021602.5MXEP directly replace BK/S501-V-2.5-R in existing designs?

A: Yes. Both parts share identical current rating (2.5A), voltage rating (250VAC), fuse type (ceramic cartridge), response time (fast blow), breaking capacity (1.5kA), and mounting type (through hole). The 5mm x 20mm form factor is standard for both, ensuring mechanical compatibility with existing fuse holders.

Q: What is the significance of the different melting I²t values (3.9 vs 2.695)?

A: Melting I²t defines the thermal energy required to melt the fuse element. The Littelfuse part (2.695) melts faster than the Eaton part (3.9) under identical fault conditions. This difference is acceptable for substitution if circuit protection timing requirements do not mandate the higher I²t value. Verify application-specific thermal response requirements before selection.

Q: Are there regulatory compliance differences between the two parts?

A: Both parts hold overlapping certifications (CCC, CSA, SEMKO, VDE). The Eaton part includes BSI, cULus, IMQ, and MITI/JET certifications. The Littelfuse part includes UL, KC, PSE, and CE certifications. Select based on target market regulatory requirements. For North American applications, both hold CSA and cULus/UL certifications.

Q: Do the dimensional differences affect fuse holder compatibility?

A: Minor dimensional variations exist (Eaton: 5.54mm dia x 21.10mm L; Littelfuse: 5.80mm dia x 22.50mm L). Both conform to the 5mm x 20mm standard form factor. Verify fuse holder mechanical tolerance specifications to confirm fit. Standard IEC 60127 fuse holders accommodate both dimensions.

Q: Which part should be selected for new designs?

A: For new designs, either part is acceptable based on supply chain strategy and target market certifications. Littelfuse offers extended operating temperature range (-55°C to 125°C) and higher inventory availability (1666 units). Eaton provides broader international certifications. Document the selected part number in design specifications to ensure consistency across production batches.

Q: Is the DC cold resistance difference (0.053 vs 0.0584 Ohms) significant?

A: The difference of 0.0054 Ohms represents approximately 10% variation, which is within normal manufacturing tolerance for ceramic fuse elements. This minor resistance difference does not affect circuit protection performance or compatibility in standard applications.