BK/MDL-4/10 Equivalent & Substitute Parts

Part Overview

The BK/MDL-4/10 is a 400 mA, 250 V AC/DC slow-blow glass cartridge fuse in 3AB/3AG package format (1/4" x 1-1/4"). This component requires a compatible fuse holder for installation. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new designs. Active alternatives from Eaton and cross-manufacturer sources provide functional equivalence with improved compliance status and availability.

Substiute Parts

BK/MDL-4/10

Eaton - Electronics DivisionIn Stock: 954BK/MDL-4/10 Datasheet

Current PartRFQ

BK/MDL-4/10-R

Eaton - Electronics DivisionIn Stock: 1160BK/MDL-4/10-R Datasheet

DirectRFQ

MDL-4/10-R

Eaton - Electronics DivisionIn Stock: 1084MDL-4/10-R Datasheet

DirectRFQ

BK/MDQ-4/10

Eaton - Electronics DivisionIn Stock: 1055BK/MDQ-4/10 Datasheet

Parametric EquivalentRFQ

MDQ-4/10

Eaton - Electronics DivisionIn Stock: 885MDQ-4/10 Datasheet

Parametric EquivalentRFQ

0034.5217

SCHURTER Inc.In Stock: 9910034.5217 Datasheet

SimilarRFQ

0034.3413

SCHURTER Inc.In Stock: 11420034.3413 Datasheet

Parametric EquivalentRFQ

0034.5218

SCHURTER Inc.In Stock: 12300034.5218 Datasheet

Parametric EquivalentRFQ

0313.400HXP

Littelfuse Inc.In Stock: 9940313.400HXP Datasheet

Parametric EquivalentRFQ

0313.400MXP

Littelfuse Inc.In Stock: 24190313.400MXP Datasheet

Parametric EquivalentRFQ

0313.400VXP

Littelfuse Inc.In Stock: 10520313.400VXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/MDL-4/10 is determined by strict equivalence across the following parameters:

Critical Parameters (Must Match Exactly):

• Current Rating: 400 mA
• Voltage Rating (AC): 250 V
• Response Time: Slow Blow
• Fuse Type: Cartridge, Glass
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4"
• Size / Dimension: 0.250" Dia x 1.250" L (6.35mm x 31.75mm)
• Mounting Type: Requires Holder

All substitute parts listed below meet these exact specifications. Substitutes are grouped into three categories:

Direct Manufacturer Equivalents (Eaton - Electronics Division): Parts with identical electrical and mechanical specifications from the original manufacturer, differing only in packaging or product status.

Parametric Equivalents (Eaton & SCHURTER): Parts meeting all critical electrical and mechanical parameters, with variations in series designation, approval agencies, or compliance certifications.

Parametric Equivalents (Littelfuse): Cross-manufacturer parts meeting all critical specifications with additional technical data (melting I²t, DC cold resistance) and active product status.

Parameter Comparison

Engineering Selection Recommendations

For New Designs and Active System Maintenance:

Select from active product status parts to ensure long-term availability and supply chain continuity. The following parts are recommended based on product status and compliance:

Primary Recommendation - Eaton Manufacturer:

• MDL-4/10-R or BK/MDL-4/10-R: Active status, RoHS compliant, maintains original manufacturer continuity. MDL-4/10-R offers standard RoHS compliance; BK/MDL-4/10-R offers ROHS3 compliance with MSL rating of 1 (Unlimited).

Primary Recommendation - Littelfuse Manufacturer:

• 0313.400MXP: Active status, ROHS3 compliant, highest inventory availability (2314 pcs), CE/CSA/UL approvals, melting I²t of 1.35, DC cold resistance of 1.875 Ohms.
• 0313.400HXP or 0313.400VXP: Active status, ROHS3 compliant, identical electrical specifications to 0313.400MXP, suitable for applications requiring alternative sourcing.

For Obsolete System Replacement:

If the original BK/MDL-4/10 must be replaced in existing equipment, the active Eaton equivalents (MDL-4/10-R or BK/MDL-4/10-R) provide direct manufacturer continuity. Cross-manufacturer Littelfuse parts (0313.400MXP, 0313.400HXP, 0313.400VXP) are functionally equivalent and offer improved compliance status.

Compliance Considerations:

• RoHS Compliance: Select ROHS3-compliant variants (BK/MDL-4/10-R, MDQ-4/10, Littelfuse 0313 series) for applications subject to RoHS directives.
• Approval Agencies: Littelfuse 0313 series carries CE, CSA, and UL approvals. Eaton MDQ-4/10 carries CSA and UL approvals. Select based on regional regulatory requirements.
• REACH Status: Littelfuse and SCHURTER parts are REACH Unaffected; Eaton parts do not specify REACH status.

Frequently Asked Questions (FAQ)

Q: Can BK/MDL-4/10 be directly replaced with MDL-4/10-R?

A: Yes. MDL-4/10-R is an active equivalent from the same manufacturer (Eaton - Electronics Division) with identical electrical and mechanical specifications. The primary difference is product status (active vs. obsolete) and RoHS compliance. Both require the same 3AB/3AG fuse holder.

Q: What is the difference between BK/MDL-4/10-R and MDL-4/10-R?

A: Both are Eaton active equivalents with identical electrical specifications. BK/MDL-4/10-R carries ROHS3 compliance with MSL rating 1 (Unlimited). MDL-4/10-R carries standard RoHS compliance. Selection depends on compliance requirements and moisture sensitivity specifications for your application.

Q: Are Littelfuse 0313.400MXP, 0313.400HXP, and 0313.400VXP interchangeable?

A: Yes. All three Littelfuse parts meet identical electrical and mechanical specifications: 400 mA, 250 V AC, slow-blow response, 3AB/3AG package, and 0.250" Dia x 1.250" L dimensions. All are active, ROHS3 compliant, and carry CE/CSA/UL approvals. Selection between variants may depend on distributor availability or internal part numbering systems.

Q: Why is the original BK/MDL-4/10 listed as obsolete?

A: Obsolete status indicates the part is no longer manufactured by Eaton - Electronics Division. Active equivalents (BK/MDL-4/10-R, MDL-4/10-R, MDQ-4/10) are available as replacements. For new designs, active parts are recommended to ensure supply chain continuity.

Q: Can I use a 375 mA fuse (0034.5217) as a substitute for the 400 mA BK/MDL-4/10?

A: No. The 0034.5217 is rated at 375 mA, not 400 mA. Current rating is a critical parameter that must match exactly. Using an undersized fuse will cause nuisance trips; using an oversized fuse compromises circuit protection. Only 400 mA rated parts are acceptable substitutes.

Q: What fuse holder is required for these cartridge fuses?

A: All listed parts require a 3AB or 3AG fuse holder compatible with 1/4" x 1-1/4" cartridge dimensions. Verify holder compatibility before installation. The fuse holder is not included with the fuse cartridge.

Q: Are there any differences in breaking capacity between substitute parts?

A: Yes. MDQ-4/10 and Littelfuse 0313 series specify 35A breaking capacity at rated voltage. BK/MDL-4/10 and MDL-4/10-R do not specify breaking capacity. For applications requiring certified breaking capacity, select MDQ-4/10 or Littelfuse equivalents.

Q: Which substitute offers the best long-term availability?

A: Littelfuse 0313.400MXP offers the highest inventory (2314 pcs) and active product status, indicating strong market availability. Eaton MDL-4/10-R and BK/MDL-4/10-R are also active with substantial inventory (1032 and 1128 pcs respectively). All three are suitable for long-term system support.