Equivalent & Substitute Parts for BK/MDQ-3/4 Glass Cartridge Fuse

Part Overview

The BK/MDQ-3/4 is a 750 mA, 250 V AC/DC slow-blow glass cartridge fuse manufactured by Eaton - Electronics Division. This fuse is designed for use in 3AB and 3AG holders with dimensions of 1/4" x 1-1/4" (6.35mm x 31.75mm). The part maintains active product status with 633 units currently in stock.

Equivalent substitute parts are necessary when the primary part becomes unavailable, when alternative compliance certifications are required, or when inventory constraints necessitate sourcing from alternative manufacturers while maintaining identical electrical and mechanical specifications.

Substiute Parts

BK/MDQ-3/4

Eaton - Electronics DivisionIn Stock: 741BK/MDQ-3/4 Datasheet

Current PartRFQ

BK/MDL-3/4-R

Eaton - Electronics DivisionIn Stock: 1037BK/MDL-3/4-R Datasheet

Parametric EquivalentRFQ

0034.5223

SCHURTER Inc.In Stock: 8320034.5223 Datasheet

Parametric EquivalentRFQ

0313.750HXP

Littelfuse Inc.In Stock: 15090313.750HXP Datasheet

Parametric EquivalentRFQ

0313.750MXP

Littelfuse Inc.In Stock: 56670313.750MXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/MDQ-3/4 is determined by strict equivalence across the following parameters:

• Current Rating: 750 mA (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Fuse Type: Cartridge, Glass (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 (exact match required)
• Breaking Capacity @ Rated Voltage: 35A (exact match required)

All substitute parts listed below meet these criteria and are therefore electrically and mechanically interchangeable with the BK/MDQ-3/4 in applications requiring a 750 mA, 250 V AC/DC slow-blow glass cartridge fuse in a 3AB/3AG holder configuration.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute (Active Status, Same Manufacturer): BK/MDL-3/4-R from Eaton - Electronics Division is the preferred substitute. This part maintains active product status, is manufactured by the same supplier as the primary part, and includes CE certification in addition to CSA and UL approvals. Current inventory is 961 units.

Secondary Substitutes (Active Status, Alternative Manufacturers): 0313.750HXP and 0313.750MXP from Littelfuse Inc. are both active products with CE, CSA, and UL certifications. These parts provide alternative sourcing from a different manufacturer while maintaining full electrical and mechanical compatibility. Inventory levels are 1440 and 5623 units respectively.

Obsolete Substitute (Not Recommended for New Designs): 0034.5223 from SCHURTER Inc. is classified as obsolete and should not be selected for new applications or long-term inventory planning, despite meeting all electrical and mechanical parameters.

Frequently Asked Questions (FAQ)

Q: Can BK/MDL-3/4-R be used as a direct replacement for BK/MDQ-3/4? A: Yes. Both parts are 750 mA, 250 V AC/DC slow-blow glass cartridge fuses in 3AB/3AG holders with identical dimensions and breaking capacity. They are electrically and mechanically interchangeable.

Q: What is the difference between the Littelfuse 0313.750HXP and 0313.750MXP? A: Both parts are electrically and mechanically identical with respect to the parameters that determine substitution eligibility. The primary difference is inventory availability, with 0313.750MXP having higher stock levels (5623 units versus 1440 units).

Q: Why is 0034.5223 listed as obsolete? A: The part is classified as obsolete by SCHURTER Inc., indicating it is no longer in active production. While it meets all electrical and mechanical specifications for substitution, it should not be selected for new designs or applications requiring long-term availability.

Q: Are all substitute parts compatible with existing 3AB and 3AG fuse holders? A: Yes. All substitute parts share the identical package designation (3AB, 3AG) and physical dimensions (0.250" Dia x 1.250" L), ensuring mechanical compatibility with existing holders.

Q: What certifications apply to each substitute part? A: BK/MDQ-3/4 carries CSA and UL certifications. BK/MDL-3/4-R, 0313.750HXP, and 0313.750MXP carry CE, CSA, and UL certifications. 0034.5223 carries CSA and UL certifications. Selection should be based on certification requirements for the target application.