BK/MDL-3/8-R Equivalent & Substitute Parts

Part Overview

The BK/MDL-3/8-R is a 375 mA, 250 V AC/DC glass cartridge fuse manufactured by Eaton - Electronics Division. This slow-blow fuse is designed for applications requiring circuit protection in the 375 mA range at 250 V AC/DC. The part features a 3AB/3AG package format with dimensions of 1/4" x 1-1/4" (6.35 mm x 31.75 mm) and requires a compatible fuse holder for installation.

The BK/MDL-3/8-R maintains Active product status with full compliance to CE, CSA, and UL approval agencies. Substitute parts become necessary when the primary part experiences supply constraints, extended lead times, or when design flexibility across multiple qualified suppliers is required for production continuity.

Substiute Parts

BK/MDL-3/8-R

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

Current PartRFQ

0034.5217

SCHURTER Inc.In Stock: 9910034.5217 Datasheet

Parametric EquivalentRFQ

0313.375HXP

Littelfuse Inc.In Stock: 10580313.375HXP Datasheet

Parametric EquivalentRFQ

0313.375MXP

LittelfuseIn Stock: 37180313.375MXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/MDL-3/8-R is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Current Rating: 375 mA
• Voltage Rating (AC): 250 V
• Fuse Type: Cartridge, Glass
• Response Time: Slow Blow
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4"
• Breaking Capacity @ Rated Voltage: 35 A
• Size / Dimension: 0.250" Dia x 1.250" L (6.35 mm x 31.75 mm)
• Mounting Type: Requires Holder
• RoHS Status: ROHS3 Compliant

All substitute parts listed below meet these mandatory parameters and are therefore electrically and mechanically interchangeable with the BK/MDL-3/8-R in applications requiring 375 mA, 250 V AC/DC circuit protection with slow-blow response characteristics.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Status):

The 0313.375HXP and 0313.375MXP from Littelfuse Inc. are the preferred substitute options for the BK/MDL-3/8-R. Both parts maintain Active product status and carry full CE, CSA, and UL approvals. The Littelfuse 313 series parts provide identical electrical and mechanical specifications with defined operating temperature ranges of -55°C to 125°C. These parts are suitable for direct replacement in all applications where the BK/MDL-3/8-R is currently specified.

Secondary Substitute (Obsolete Status):

The 0034.5217 from SCHURTER Inc. meets all mandatory electrical and mechanical parameters but carries Obsolete product status. This part holds CSA and UL approvals but lacks CE certification. The 0034.5217 is suitable for substitution only in applications where CE compliance is not required and where long-term supply availability is not a design consideration.

Compliance Considerations:

All substitute parts maintain ROHS3 compliance and REACH Unaffected status, consistent with the primary part. Applications requiring CE certification should utilize only the 0313.375HXP or 0313.375MXP options.

Frequently Asked Questions (FAQ)

Q: Can the 0313.375HXP or 0313.375MXP be used as direct replacements for the BK/MDL-3/8-R?

A: Yes. Both Littelfuse parts are parametric equivalents with identical current rating (375 mA), voltage rating (250 V AC), fuse type (cartridge glass), response time (slow blow), package format (3AB/3AG), and physical dimensions (1/4" x 1-1/4"). They are electrically and mechanically interchangeable.

Q: What is the difference between the 0313.375HXP and 0313.375MXP?

A: Both parts are from the Littelfuse 313 series and share identical electrical specifications, voltage ratings, current ratings, and physical dimensions. They are functionally equivalent for substitution purposes.

Q: Why is the 0034.5217 listed as a secondary option?

A: The 0034.5217 carries Obsolete product status and lacks CE certification. While it meets all mandatory electrical and mechanical parameters, its obsolete status indicates reduced availability and potential supply chain risk. It is suitable only for applications where CE compliance is not required.

Q: Are there any resistance differences between the main part and substitutes?

A: The BK/MDL-3/8-R has a DC cold resistance of 1.567 Ohms, while the Littelfuse substitutes (0313.375HXP and 0313.375MXP) have 2.095 Ohms. The SCHURTER 0034.5217 does not specify DC cold resistance. These differences do not affect interchangeability for standard circuit protection applications.

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

A: Yes. All parts use the 3AB/3AG package format with identical 1/4" x 1-1/4" dimensions and require compatible 3AB/3AG fuse holders. No holder modifications are necessary when substituting between these parts.

Q: What approvals should I verify for my application?

A: The BK/MDL-3/8-R and Littelfuse substitutes (0313.375HXP, 0313.375MXP) carry CE, CSA, and UL approvals. The SCHURTER 0034.5217 carries CSA and UL approvals only. Verify that your application requirements match the certification profile of the selected part.

Q: Is the operating temperature range important for substitution?

A: The BK/MDL-3/8-R does not specify an operating temperature range. The substitute parts specify -55°C to 125°C. If your application operates within this range, substitution is valid. If your application requires operation outside this range, consult the specific thermal requirements of your circuit design.