Equivalent & Substitute Parts for BK/C520-2.5A

Part Overview

The BK/C520-2.5A is a 2.5 A 250 V AC DC glass cartridge fuse manufactured by Eaton - Electronics Division. This fuse is designed for use in 2AG holders with dimensions of 5mm x 15mm and provides fast-blow protection characteristics. The part is classified as obsolete, necessitating identification of active equivalent and substitute components that maintain electrical and mechanical compatibility with existing circuit protection applications.

Substiute Parts

BK/C520-2.5A

Eaton - Electronics DivisionIn Stock: 839BK/C520-2.5A Datasheet

Current PartRFQ

BK/C520-2.5-R

Eaton - Electronics DivisionIn Stock: 812BK/C520-2.5-R Datasheet

DirectRFQ

022502.5HXP

Littelfuse Inc.In Stock: 1426022502.5HXP Datasheet

DirectRFQ

022502.5MXP

Littelfuse Inc.In Stock: 1600022502.5MXP Datasheet

DirectRFQ

022502.5VXP

Littelfuse Inc.In Stock: 749022502.5VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/C520-2.5A is determined by the following critical parameters:

Primary Compatibility Criteria:

• Current Rating: 2.5 A (exact match required)
• Voltage Rating - AC: 250 V (exact match required)
• Package / Case: 2AG, 5mm x 15mm (exact match required for holder compatibility)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Fast Blow (exact match required)

Secondary Compatibility Criteria:

• Mounting Type: Requires Holder (consistent across all substitutes)
• Breaking Capacity @ Rated Voltage: 100A minimum (all substitutes meet or exceed)
• Approval Agencies: CSA and UL certifications present (all substitutes maintain or expand certifications)

All identified substitute parts meet these criteria. The Littelfuse 022502.5MXP, 022502.5HXP, and 022502.5VXP variants provide additional DC voltage rating capability (125 V DC) and expanded operating temperature range (-55°C ~ 125°C) compared to the main part, while maintaining full AC compatibility and mechanical interchangeability.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: BK/C520-2.5-R

The BK/C520-2.5-R is the direct Eaton equivalent to the obsolete BK/C520-2.5A. This part maintains identical electrical specifications, mechanical dimensions, and performance characteristics while offering active product status and ROHS3 compliance. Selection of this part ensures continuity with the original design intent and manufacturer support.

Alternative Recommendations: Littelfuse 022502.5MXP, 022502.5HXP, 022502.5VXP

The Littelfuse Series 225 fuses (022502.5MXP, 022502.5HXP, 022502.5VXP) provide full electrical and mechanical compatibility with the BK/C520-2.5A. These parts are active products with expanded certifications (CE, CSA, PSE, UL) and ROHS3 compliance. The addition of 125 V DC rating and extended operating temperature range (-55°C ~ 125°C) provides enhanced capability for applications requiring DC circuit protection or operation in temperature-extreme environments. The three Littelfuse variants are electrically and mechanically identical, with interchangeable performance characteristics.

Compliance Considerations:

All substitute parts maintain CSA and UL certifications required for the original application. The Littelfuse variants add CE and PSE certifications, expanding regulatory acceptance. All substitutes achieve ROHS3 compliance, addressing environmental and regulatory requirements not met by the obsolete BK/C520-2.5A.

Frequently Asked Questions (FAQ)

Q: Can BK/C520-2.5-R be used as a direct replacement for BK/C520-2.5A?

A: Yes. The BK/C520-2.5-R is the active equivalent manufactured by Eaton. It maintains identical current rating (2.5 A), AC voltage rating (250 V), package dimensions (2AG, 5mm x 15mm), response time (fast blow), and breaking capacity (100A). Physical and electrical interchangeability is complete.

Q: What is the difference between the Littelfuse 022502.5MXP, 022502.5HXP, and 022502.5VXP?

A: These three Littelfuse parts are electrically and mechanically identical. All three provide 2.5 A current rating, 250 V AC / 125 V DC voltage rating, 2AG package compatibility, fast-blow response, and identical melting I²t (2.68). They differ only in packaging designation and inventory availability. Any of the three can be selected based on supply and procurement requirements.

Q: Are the Littelfuse substitutes compatible with existing 2AG fuse holders?

A: Yes. All Littelfuse substitutes use the 2AG package specification (5mm x 15mm) and are designed for use in standard 2AG holders. Physical dimensions are 0.177" Dia x 0.570" L (4.50mm x 14.48mm), which is compatible with 2AG holder specifications.

Q: What is the significance of the 125 V DC rating on Littelfuse parts?

A: The Littelfuse variants include a 125 V DC rating in addition to the 250 V AC rating. This specification indicates the fuse can provide protection in DC circuits up to 125 V. The original BK/C520-2.5A does not specify a DC rating. For AC-only applications, this additional capability does not affect performance. For applications requiring DC protection, the Littelfuse parts provide expanded functionality.

Q: How do the melting I²t values differ between parts?

A: The BK/C520-2.5A has a melting I²t of 2.9, while all Littelfuse substitutes have a melting I²t of 2.68. This represents a 7.6% reduction in thermal energy required for fuse melting. Both values fall within the fast-blow fuse category and maintain the same current rating (2.5 A). The difference reflects manufacturing variations between manufacturers and does not affect compatibility for standard circuit protection applications.

Q: What certifications are required for my application?

A: The original BK/C520-2.5A carries CSA and UL certifications. The BK/C520-2.5-R maintains these certifications. The Littelfuse substitutes expand certifications to include CE and PSE in addition to CSA and UL. Verify your application's specific certification requirements and select the part that meets those requirements. All substitutes meet or exceed the original certification scope.

Q: Is RoHS compliance a factor in selecting a substitute?

A: The original BK/C520-2.5A is RoHS non-compliant. All substitute parts (BK/C520-2.5-R and all Littelfuse variants) are ROHS3 compliant. If your application or procurement requirements mandate RoHS compliance, any of the substitute parts satisfies this requirement.

Q: Can I mix different substitute parts in the same circuit or equipment?

A: Yes. All substitute parts maintain identical electrical specifications (2.5 A, 250 V AC, fast-blow response) and mechanical compatibility (2AG package). Mixing BK/C520-2.5-R with any of the Littelfuse variants, or mixing different Littelfuse variants, does not create compatibility issues. However, for consistency in maintenance and inventory management, standardizing on a single part number is recommended.