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

Part Overview

The MDQ-3/4 is a 750 mA, 250 V AC/DC slow-blow glass fuse cartridge manufactured by Eaton - Electronics Division. This component requires a 3AB or 3AG holder and is designed for circuit protection applications requiring a 1/4" x 1-1/4" form factor. The part maintains active product status with 1128 units in current inventory. Equivalent substitute parts are available from multiple manufacturers including Littelfuse Inc. and SCHURTER Inc., providing alternative sourcing options while maintaining identical electrical and mechanical specifications.

Substiute Parts

MDQ-3/4

Eaton - Electronics DivisionIn Stock: 1196MDQ-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 of the MDQ-3/4 fuse cartridge is determined by strict equivalence across the following parameters:

• Current Rating: 750 mA (exact match required)
• Voltage Rating: 250 V AC (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)
• Physical Dimensions: 0.250" Dia x 1.250" L (exact match required)
• Breaking Capacity: 35A @ rated voltage (exact match required)

All substitute parts listed maintain identical values across these critical parameters, ensuring direct functional and mechanical compatibility within 3AB and 3AG holder assemblies. Variations in secondary parameters such as melting I²t, DC cold resistance, and compliance certifications do not affect substitutability for the primary circuit protection function.

Parameter Comparison

Engineering Selection Recommendations

Active Status Parts: BK/MDL-3/4-R, 0313.750HXP, and 0313.750MXP maintain active product status and are suitable for new designs and ongoing production requirements. These parts carry expanded approval certifications including CE marking in addition to CSA and UL approvals.

Primary Eaton Substitute: BK/MDL-3/4-R is the direct Eaton equivalent within the MDL series, offering continuity of supply from the original manufacturer with enhanced compliance certifications.

Littelfuse Alternatives: Both 0313.750HXP and 0313.750MXP from the Littelfuse 313 series provide active alternatives with identical electrical and mechanical specifications. These parts are available in higher inventory quantities (1440 and 5623 units respectively) and carry full CE, CSA, and UL approvals.

Obsolete Part Consideration: The SCHURTER 0034.5223 maintains obsolete product status and should not be selected for new applications despite meeting all electrical and mechanical parameters.

Frequently Asked Questions (FAQ)

Q: Can MDQ-3/4 be directly replaced with BK/MDL-3/4-R?

A: Yes. Both parts are manufactured by Eaton - Electronics Division and maintain identical current rating (750 mA), voltage rating (250 V AC), response time (slow blow), package designation (3AB, 3AG), and physical dimensions (0.250" Dia x 1.250" L). Direct substitution is supported within 3AB and 3AG holder assemblies.

Q: Are Littelfuse 0313.750HXP and 0313.750MXP interchangeable with MDQ-3/4?

A: Yes. Both Littelfuse parts meet all critical substitution parameters: 750 mA current rating, 250 V AC voltage rating, slow-blow response, 3AB/3AG package compatibility, and 0.250" Dia x 1.250" L dimensions. Both parts carry active product status with CSA, UL, and CE approvals.

Q: What is the difference between 0313.750HXP and 0313.750MXP?

A: Both parts are from the Littelfuse 313 series and maintain identical electrical specifications and package dimensions. The difference lies in inventory availability, with 0313.750MXP available in significantly higher quantities (5623 units versus 1440 units).

Q: Why is SCHURTER 0034.5223 listed as obsolete?

A: The 0034.5223 carries obsolete product status designation. While it meets all electrical and mechanical parameters for substitution, it should not be selected for new designs or applications requiring long-term supply assurance.

Q: Do all substitute parts require the same holder type?

A: Yes. All listed substitute parts require 3AB or 3AG holder assemblies. Physical dimensions of 0.250" Dia x 1.250" L are identical across all parts, ensuring mechanical compatibility within existing holder installations.

Q: What compliance certifications apply to substitute parts?

A: The MDQ-3/4 carries CSA and UL approvals. Substitute parts BK/MDL-3/4-R, 0313.750HXP, and 0313.750MXP carry expanded certifications including CE marking in addition to CSA and UL. The obsolete SCHURTER part carries CSA and UL approvals only.