Equivalent & Substitute Parts for BK/MDA-1/8 Ceramic Cartridge Fuse

Part Overview

The BK/MDA-1/8 is a 125 mA, 250 V AC/DC ceramic cartridge fuse manufactured by Eaton - Electronics Division. This fuse is designed for use in 3AB and 3AG holders with a 1/4" x 1-1/4" form factor and provides slow-blow response characteristics. The product is currently obsolete, making identification of equivalent substitute parts essential for system maintenance, repair, and component replacement in existing installations.

Substiute Parts

BK/MDA-1/8

Eaton - Electronics DivisionIn Stock: 1200BK/MDA-1/8 Datasheet

Current PartRFQ

0326.125HXP

Littelfuse Inc.In Stock: 6940326.125HXP Datasheet

DirectRFQ

0326.125MXP

Littelfuse Inc.In Stock: 9370326.125MXP Datasheet

DirectRFQ

0326.125VXP

Littelfuse Inc.In Stock: 9960326.125VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BK/MDA-1/8 are determined by strict equivalence across the following critical parameters:

• Current Rating: 125 mA (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
• Size / Dimension: 0.250" Dia x 1.250" L (6.35mm x 31.75mm) (exact match required)
• Mounting Type: Requires Holder (exact match required)

All three substitute parts from Littelfuse Inc. (0326.125HXP, 0326.125MXP, 0326.125VXP) meet these criteria without deviation. These parts are functionally and mechanically interchangeable with the original BK/MDA-1/8.

Parameter Comparison

Engineering Selection Recommendations

The three Littelfuse substitute parts (0326.125HXP, 0326.125MXP, 0326.125VXP) are direct functional equivalents to the obsolete BK/MDA-1/8. Selection among these three variants should be based on application-specific requirements and availability:

Product Status: All three substitute parts are active products from Littelfuse Inc., ensuring ongoing availability and supply chain continuity compared to the obsolete Eaton original.

Compliance and Certifications: The Littelfuse substitutes carry CE approval and are ROHS3 compliant, providing enhanced regulatory compliance compared to the original non-compliant part. These certifications support use in modern equipment and systems with current environmental and safety standards.

Electrical Performance: All substitute parts provide identical electrical characteristics (125 mA, 250 V AC/DC, slow-blow response) with documented breaking capacity of 100A and melting I²t of 0.1, offering performance data not specified for the original part.

Mechanical Compatibility: All substitute parts maintain identical physical dimensions (0.250" Dia x 1.250" L) and package specifications (3AB, 3AG), ensuring direct mechanical fit in existing 3AB and 3AG fuse holders without modification.

Frequently Asked Questions (FAQ)

Q: Are the Littelfuse 0326.125HXP, 0326.125MXP, and 0326.125VXP parts fully interchangeable with the BK/MDA-1/8?

A: Yes. All three Littelfuse parts are direct substitutes. They match the BK/MDA-1/8 across all critical parameters: 125 mA current rating, 250 V AC voltage rating, ceramic cartridge type, slow-blow response, and 3AB/3AG package specifications with identical physical dimensions.

Q: What is the difference between the three Littelfuse substitute part numbers?

A: The provided data shows that 0326.125HXP, 0326.125MXP, and 0326.125VXP have identical electrical and mechanical specifications. The part number suffix variations (HXP, MXP, VXP) indicate different product variants within the Littelfuse 326 series, but all three meet the substitution requirements for the BK/MDA-1/8.

Q: Will these substitute fuses work in my existing 3AB and 3AG fuse holders?

A: Yes. All substitute parts are designed for 3AB and 3AG holders and maintain the exact physical dimensions of the original part (0.250" Dia x 1.250" L). No holder modification is required.

Q: Why should I use the Littelfuse substitutes instead of the original Eaton part?

A: The original BK/MDA-1/8 is obsolete and no longer manufactured. The Littelfuse substitutes are active products with current availability. Additionally, they provide ROHS3 compliance and CE approval, meeting modern regulatory requirements.

Q: Are there any electrical performance differences between the original and substitute parts?

A: The substitute parts provide documented electrical specifications (100A breaking capacity, 0.1 melting I²t, 22.45 Ohms DC cold resistance, -55°C to 125°C operating temperature) that were not specified for the original part. These specifications confirm equivalent or superior performance characteristics.

Q: Can I mix different Littelfuse variants in the same application?

A: Yes. Since 0326.125HXP, 0326.125MXP, and 0326.125VXP have identical electrical and mechanical specifications, they are interchangeable within the same application.