BK/MDL-3/8 Equivalent & Substitute Parts

Part Overview

The BK/MDL-3/8 is a 375 mA, 250 V AC/DC slow-blow glass 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 carries an obsolete product status, necessitating identification of active equivalent and substitute components that maintain electrical and mechanical compatibility for continued circuit protection applications.

Substiute Parts

BK/MDL-3/8

Eaton - Electronics DivisionIn Stock: 1024BK/MDL-3/8 Datasheet

Current PartRFQ

BK/MDL-3/8-R

Eaton - Electronics DivisionIn Stock: 1206BK/MDL-3/8-R Datasheet

DirectRFQ

MDL-3/8-R

Eaton - Electronics DivisionIn Stock: 945MDL-3/8-R Datasheet

DirectRFQ

BK/MDQ-3/8

Eaton - Electronics DivisionIn Stock: 1106BK/MDQ-3/8 Datasheet

Parametric EquivalentRFQ

MDQ-3/8

Eaton - Electronics DivisionIn Stock: 970MDQ-3/8 Datasheet

Parametric EquivalentRFQ

0313.375HXP

Littelfuse Inc.In Stock: 10580313.375HXP Datasheet

SimilarRFQ

0034.5217

SCHURTER Inc.In Stock: 9910034.5217 Datasheet

Parametric EquivalentRFQ

0313.375MXP

LittelfuseIn Stock: 37180313.375MXP Datasheet

Parametric EquivalentRFQ

0313.375VXP

Littelfuse Inc.In Stock: 7030313.375VXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/MDL-3/8 is determined by strict equivalence across the following critical parameters: current rating (375 mA), voltage rating (250 V AC), response time (slow blow), fuse type (cartridge glass), package designation (3AB, 3AG), and physical dimensions (0.250" Dia x 1.250" L). All substitute parts listed maintain these electrical and mechanical specifications without deviation.

Substitute parts are grouped into three categories:

Direct Manufacturer Equivalents (Eaton - Electronics Division): BK/MDL-3/8-R and MDL-3/8-R represent direct successors to the obsolete BK/MDL-3/8, sharing identical electrical characteristics and holder compatibility. These parts differ primarily in product status (active versus obsolete) and compliance certifications.

Parametric Equivalents (Eaton - Electronics Division): BK/MDQ-3/8 and MDQ-3/8 belong to the MDQ series and maintain all critical electrical and mechanical parameters. Series designation change does not affect functional compatibility within the specified holder systems.

Cross-Manufacturer Equivalents: Parts from Littelfuse Inc. (0313.375HXP, 0313.375MXP, 0313.375VXP) and SCHURTER Inc. (0034.5217) provide functional equivalence across manufacturers while maintaining identical current, voltage, response time, and physical specifications.

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: BK/MDL-3/8-R or MDL-3/8-R are the recommended direct replacements for the obsolete BK/MDL-3/8. Both parts are manufactured by Eaton - Electronics Division, maintain identical electrical and mechanical specifications, and carry active product status. BK/MDL-3/8-R provides enhanced compliance with ROHS3 certification and CE approval in addition to existing CSA and UL certifications. MDL-3/8-R offers equivalent compliance with RoHS certification and CE approval.

Secondary Selection: BK/MDQ-3/8 and MDQ-3/8 provide parametric equivalence within the Eaton product portfolio. These parts maintain all critical electrical parameters and holder compatibility. Selection of MDQ series components is appropriate where MDL series availability is constrained.

Cross-Manufacturer Selection: Littelfuse 0313.375HXP, 0313.375MXP, and 0313.375VXP provide functionally equivalent alternatives with enhanced compliance certifications (ROHS3, CE, CSA, UL). These parts are suitable for applications requiring cross-manufacturer sourcing flexibility. The Littelfuse 313 series components carry active product status and demonstrate superior inventory availability.

Obsolete Part Consideration: SCHURTER 0034.5217 carries obsolete product status and should not be selected for new designs or long-term supply requirements, despite ROHS3 compliance and active certification history.

Frequently Asked Questions (FAQ)

Q: Can BK/MDL-3/8-R directly replace the obsolete BK/MDL-3/8?

A: Yes. BK/MDL-3/8-R is a direct manufacturer equivalent with identical current rating (375 mA), voltage rating (250 V AC), response time (slow blow), and physical dimensions (0.250" Dia x 1.250" L). Both parts are compatible with 3AB and 3AG holder systems. The primary differences are product status (active versus obsolete) and enhanced compliance certifications on the replacement part.

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

A: MDL and MDQ series fuses from Eaton maintain identical electrical specifications for the 375 mA, 250 V AC rating. Series designation reflects internal design or manufacturing process differences that do not affect electrical performance or holder compatibility. Both series are suitable for 3AB and 3AG applications.

Q: Are Littelfuse 313 series fuses compatible with Eaton MDL/MDQ holders?

A: Yes. Littelfuse 0313.375HXP, 0313.375MXP, and 0313.375VXP maintain identical physical dimensions (0.250" Dia x 1.250" L) and are designed for 3AB and 3AG holder systems. Electrical specifications (375 mA, 250 V AC, slow blow response) are equivalent across manufacturers.

Q: What compliance advantages does BK/MDL-3/8-R offer over the original BK/MDL-3/8?

A: BK/MDL-3/8-R carries ROHS3 compliance certification and CE approval in addition to CSA and UL certifications held by the original part. These certifications address environmental and safety regulatory requirements in European and North American markets.

Q: Can I use 0034.5217 from SCHURTER as a long-term replacement?

A: No. Although 0034.5217 maintains electrical and mechanical equivalence, it carries obsolete product status. For applications requiring sustained component availability, select active parts such as BK/MDL-3/8-R, MDL-3/8-R, or Littelfuse 313 series components.

Q: Are there differences in DC cold resistance among substitute parts?

A: Yes. DC cold resistance values vary among substitute parts (ranging from 1.567 to 2.8 Ohms) but remain within acceptable parameters for the 375 mA, 250 V AC fuse category. These variations do not affect circuit protection performance or holder compatibility.

Q: Which substitute part offers the highest inventory availability?

A: Littelfuse 0313.375MXP demonstrates the highest inventory availability with 3,666 pieces in stock, followed by BK/MDL-3/8-R with 1,162 pieces. Both parts carry active product status and full compliance certifications.