BK/MDA-4/10 Ceramic Fuse Equivalent & Substitute Parts

Part Overview

The BK/MDA-4/10 is a 400 mA, 250 V AC ceramic cartridge fuse manufactured by Eaton Electronics Division. This fuse is designed for 3AB and 3AG holder applications with dimensions of 0.250" diameter by 1.250" length (6.35mm x 31.75mm). The part operates as a slow-blow fuse cartridge requiring an external holder for installation.

The BK/MDA-4/10 is classified as obsolete. Substitute parts are necessary to maintain system functionality and ensure continued availability for new designs and field replacements. Active equivalent models from both Eaton and Littelfuse provide direct functional replacement with enhanced compliance and performance characteristics.

Substiute Parts

BK/MDA-4/10

Eaton - Electronics DivisionIn Stock: 1176BK/MDA-4/10 Datasheet

Current PartRFQ

BK/MDA-4/10-R

Eaton - Electronics DivisionIn Stock: 736BK/MDA-4/10-R Datasheet

DirectRFQ

MDA-4/10-R

Eaton - Electronics DivisionIn Stock: 1098MDA-4/10-R Datasheet

DirectRFQ

0326.400HXP

Littelfuse Inc.In Stock: 9260326.400HXP Datasheet

DirectRFQ

0326.400MXP

Littelfuse Inc.In Stock: 7410326.400MXP Datasheet

DirectRFQ

0326.400VXP

Littelfuse Inc.In Stock: 7750326.400VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/MDA-4/10 is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Current Rating: 400 mA
• Voltage Rating (AC): 250 V
• Fuse Type: Cartridge, Ceramic
• Response Time: Slow Blow
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4"
• Size / Dimension: 0.250" Dia x 1.250" L (6.35mm x 31.75mm)
• Mounting Type: Requires Holder

All substitute parts listed meet these mandatory parameters. Littelfuse 326 series fuses provide additional DC voltage rating (125 V DC) and enhanced breaking capacity specifications not present in the original part, while maintaining full AC parameter compatibility. Eaton MDA series replacements provide direct parameter equivalence with improved RoHS compliance status.

Parameter Comparison

Engineering Selection Recommendations

Eaton MDA Series Substitutes (BK/MDA-4/10-R, MDA-4/10-R):

These parts provide direct functional equivalence to the BK/MDA-4/10 with identical electrical and mechanical specifications. Both are classified as active products with ROHS3 compliance and CE certification in addition to CSA and UL approvals. The BK/MDA-4/10-R is packaged in bulk format, while MDA-4/10-R offers the same specifications. Selection between these two Eaton options depends on packaging requirements and inventory availability. Both are suitable for applications requiring AC-only operation at 250 V.

Littelfuse 326 Series Substitutes (0326.400HXP, 0326.400MXP, 0326.400VXP):

These three Littelfuse models provide full AC parameter compatibility with the original part while adding DC voltage capability (125 V DC) and enhanced breaking capacity (100A AC, 10kA DC). All three are active products with ROHS3 compliance, CE certification, and identical electrical characteristics. The three model variants (HXP, MXP, VXP) represent different internal construction or performance grades within the 326 series, all meeting the same external specifications. These parts are suitable for applications requiring either AC-only operation or combined AC/DC operation at the specified voltage levels.

Compliance Considerations:

All substitute parts hold active product status and provide enhanced regulatory compliance compared to the obsolete BK/MDA-4/10. The addition of CE certification to existing CSA and UL approvals expands geographic applicability. ROHS3 compliance ensures compatibility with modern procurement and environmental standards.

Frequently Asked Questions (FAQ)

Q: Can the BK/MDA-4/10-R and MDA-4/10-R be used interchangeably with the original BK/MDA-4/10?

A: Yes. Both Eaton replacements maintain identical electrical and mechanical specifications: 400 mA current rating, 250 V AC voltage rating, slow-blow response, and 3AB/3AG package compatibility. The primary differences are product status (active versus obsolete) and enhanced compliance certifications.

Q: What is the difference between the Littelfuse 0326.400HXP, 0326.400MXP, and 0326.400VXP models?

A: All three Littelfuse models share identical external electrical and mechanical specifications for AC operation (400 mA, 250 V AC, slow-blow, 3AB/3AG package). The model designations (HXP, MXP, VXP) indicate different internal construction variants within the 326 series. All three are functionally equivalent for the BK/MDA-4/10 replacement application.

Q: Do the Littelfuse 326 series fuses provide additional capabilities beyond the original part?

A: Yes. The Littelfuse 326 series fuses include DC voltage rating (125 V DC) and specified breaking capacity (100A AC, 10kA DC) not documented in the original BK/MDA-4/10 specifications. These represent enhanced performance characteristics. For AC-only applications, the Littelfuse parts function identically to the original.

Q: Are all substitute parts compatible with existing 3AB and 3AG holders?

A: Yes. All substitute parts maintain the identical package specification (3AB, 3AG, 1/4" x 1-1/4") and physical dimensions (0.250" diameter x 1.250" length). Direct mechanical compatibility with existing holders is assured.

Q: Which substitute should be selected for new designs?

A: For new designs, any of the active substitute parts are appropriate. Eaton MDA series options (BK/MDA-4/10-R or MDA-4/10-R) provide direct parameter equivalence. Littelfuse 326 series options (0326.400HXP, 0326.400MXP, or 0326.400VXP) provide equivalent AC performance with additional DC capability. Selection depends on application requirements, supplier preference, and availability.

Q: What is the significance of the RoHS3 compliance status?

A: ROHS3 compliance indicates the substitute parts meet current Restriction of Hazardous Substances regulations. The original BK/MDA-4/10 is RoHS non-compliant, making the compliant substitutes necessary for applications subject to environmental and procurement standards requiring RoHS compliance.

Q: Can the BK/MDA-4/10 be used in DC applications?

A: The original part specification lists 250 V AC rating only, with no DC voltage rating documented. The Littelfuse 326 series substitutes explicitly support 125 V DC operation. For DC applications, Littelfuse 326 series parts are the appropriate selection.