Equivalent & Substitute Parts for BK/MDL-3/4

Part Overview

The BK/MDL-3/4 is a 750 mA, 250 V AC/DC slow-blow glass cartridge fuse in 3AB/3AG package format with dimensions of 0.250" diameter × 1.250" length (6.35 mm × 31.75 mm). This fuse requires a compatible holder for installation and is designed for general-purpose circuit protection applications.

The BK/MDL-3/4 carries an obsolete product status. Equivalent and substitute parts are available from Eaton and alternative manufacturers to maintain circuit protection functionality in applications requiring this current and voltage rating.

Substiute Parts

BK/MDL-3/4

Eaton - Electronics DivisionIn Stock: 1130BK/MDL-3/4 Datasheet

Current PartRFQ

BK/MDL-3/4-R

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

DirectRFQ

MDL-3/4-R

Eaton - Electronics DivisionIn Stock: 1041MDL-3/4-R Datasheet

DirectRFQ

BK/MDL-3/4SX-R

Eaton - Electronics DivisionIn Stock: 773BK/MDL-3/4SX-R Datasheet

Parametric EquivalentRFQ

BK/MDQ-3/4

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

Parametric EquivalentRFQ

MDQ-3/4

Eaton - Electronics DivisionIn Stock: 1196MDQ-3/4 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

0313.750VXP

Littelfuse Inc.In Stock: 8290313.750VXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BK/MDL-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" × 1-1/4" (exact match required)
• Size / Dimension: 0.250" Dia × 1.250" L (exact match required)
• Breaking Capacity @ Rated Voltage: 35 A (exact match required)
• Mounting Type: Requires Holder (exact match required)

All substitute parts listed below meet these electrical and mechanical parameters and are therefore functionally equivalent for circuit protection applications requiring the BK/MDL-3/4 specifications.

Parameter Comparison

Engineering Selection Recommendations

Eaton Direct Replacements (Same Manufacturer)

BK/MDL-3/4-R, MDL-3/4-R, BK/MDL-3/4SX-R, BK/MDQ-3/4, and MDQ-3/4 are all active Eaton products that meet the electrical and mechanical specifications of the obsolete BK/MDL-3/4. These parts carry active product status and provide continuity within the Eaton product line. BK/MDL-3/4-R and MDL-3/4-R include CE certification in addition to CSA and UL approvals. BK/MDL-3/4-R, MDL-3/4-R, and BK/MDL-3/4SX-R are RoHS compliant, addressing environmental compliance requirements.

Cross-Manufacturer Alternatives

Littelfuse 0313.750HXP, 0313.750MXP, and 0313.750VXP are active products from an established fuse manufacturer. All three carry CE, CSA, and UL certifications and are ROHS3 compliant. These parts are functionally equivalent across all specified electrical and mechanical parameters.

SCHURTER 0034.5223 is an obsolete product but remains available in inventory. It carries CSA and UL certifications and is ROHS3 compliant.

Product Status Considerations

For new designs or long-term supply requirements, selection from active product lines is appropriate. Active Eaton alternatives include BK/MDL-3/4-R, MDL-3/4-R, BK/MDL-3/4SX-R, BK/MDQ-3/4, MDQ-3/4, and all Littelfuse 313 series variants. These ensure ongoing manufacturer support and availability.

Frequently Asked Questions (FAQ)

Q: Can I use any of these substitute parts directly in place of the BK/MDL-3/4?

A: Yes. All listed substitute parts meet the required electrical parameters (750 mA, 250 V AC, slow-blow response) and mechanical specifications (3AB/3AG package, 0.250" × 1.250" dimensions). All require the same holder type. Direct substitution is supported based on parameter equivalence.

Q: What is the difference between the Eaton MDL and MDQ series fuses?

A: Both series meet the same electrical and mechanical specifications for the 750 mA, 250 V rating. The MDQ series represents an alternative product line within Eaton's portfolio. Selection between MDL and MDQ series is based on availability and organizational procurement preferences, as both are functionally equivalent.

Q: Are the Littelfuse 313 series variants (HXP, MXP, VXP) interchangeable?

A: Yes. The 0313.750HXP, 0313.750MXP, and 0313.750VXP all meet identical electrical and mechanical specifications for 750 mA, 250 V slow-blow operation in the 3AB/3AG package. Differences between variants relate to internal construction characteristics not specified in the provided parameters. All three are active products with full certifications.

Q: Does the BK/MDL-3/4-R differ from MDL-3/4-R?

A: Both parts are active Eaton products with identical electrical and mechanical specifications. The "BK/" prefix designation represents a packaging or distribution variant. Both are functionally equivalent for circuit protection applications.

Q: What RoHS compliance status should I select?

A: For applications subject to RoHS requirements, select from ROHS3 compliant parts: BK/MDL-3/4-R, MDL-3/4-R, BK/MDL-3/4SX-R, 0034.5223, 0313.750HXP, 0313.750MXP, or 0313.750VXP. For applications without RoHS requirements, all listed parts are acceptable.

Q: Are there any certifications I should prioritize?

A: All substitute parts carry CSA and UL certifications, meeting standard safety requirements. BK/MDL-3/4-R, MDL-3/4-R, and all Littelfuse 313 series variants additionally carry CE certification. Selection based on certification should align with regional regulatory requirements for the application.

Q: Can I use the obsolete SCHURTER 0034.5223 as a substitute?

A: Yes. The 0034.5223 meets all electrical and mechanical specifications and carries CSA and UL certifications. However, as an obsolete product, long-term availability may be limited. For new applications or long-term supply planning, active products are recommended.

Q: What holder type is required for these fuses?

A: All listed fuses require a 3AB or 3AG compatible holder. The fuse dimensions of 0.250" diameter × 1.250" length (6.35 mm × 31.75 mm) are standardized across all substitute parts. Verify that existing holders in your application support the 3AB/3AG package format.