Equivalent & Substitute Parts for BK/MDL-5 Glass Cartridge Fuse

Part Overview

The BK/MDL-5 is a 5 A, 250 V AC/DC slow-blow glass cartridge fuse manufactured by Eaton - Electronics Division. This fuse is designed for use in 3AB and 3AG holders with dimensions of 1/4" x 1-1/4" (6.35 mm x 31.75 mm). The main part carries an obsolete product status, making identification of active equivalent and substitute parts essential for ongoing system maintenance and component procurement.

Substitute parts are necessary because the BK/MDL-5 is no longer in active production. Active alternatives from both Eaton and Littelfuse maintain identical electrical and mechanical specifications, ensuring direct functional replacement without circuit redesign.

Key Parameters

Parameter	Specification
Current Rating	5 A
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 (6.35 mm x 31.75 mm)
Breaking Capacity @ Rated Voltage	200 A
Mounting Type	Requires Holder

Substitute Part Grouping Explanation

Substitution of the BK/MDL-5 is determined by strict equivalence across the following parameters:

Critical Matching Parameters:

Current Rating: 5 A (exact match required)
Voltage Rating (AC): 250 V (exact match required)
Response Time: Slow Blow (exact match required)
Fuse Type: Cartridge, Glass (exact match required)
Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
Size / Dimension: 0.250" Dia x 1.250" L (exact match required)
Breaking Capacity @ Rated Voltage: 200 A (exact match required)

All substitute parts listed maintain these critical parameters. Variations in secondary parameters such as DC Cold Resistance, Melting I²t, and RoHS compliance do not affect functional substitution but are documented for engineering reference.

Substitute parts are organized into two categories:

Direct Manufacturer Substitutes (Eaton - Electronics Division):

BK/MDL-5-R
MDL-5-R

Parametric Equivalents (Eaton - Electronics Division):

BK/MDQ-5
MDQ-5

Parametric Equivalents (Littelfuse Inc.):

0313005.HXIDP
0313005.HXP
0313005.MXP
0313005.VXIDP
0313005.VXP

Parameter Comparison

Part Number	Manufacturer	Current Rating (A)	Voltage Rating (V AC)	Response Time	Fuse Type	Package / Case	Size (Dia x L)	Breaking Capacity (A)	Product Status	DC Cold Resistance (Ohms)	Melting I²t
BK/MDL-5	Eaton	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Obsolete	0.023	32
BK/MDL-5-R	Eaton	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.025	32
MDL-5-R	Eaton	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.025	32
BK/MDQ-5	Eaton	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0265	Not specified
MDQ-5	Eaton	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0265	Not specified
0313005.HXIDP	Littelfuse	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0214	140
0313005.HXP	Littelfuse	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0214	140
0313005.MXP	Littelfuse	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0214	276
0313005.VXIDP	Littelfuse	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0214	140
0313005.VXP	Littelfuse	5	250	Slow Blow	Cartridge, Glass	3AB, 3AG, 1/4" x 1-1/4"	0.250" x 1.250"	200	Active	0.0214	140

Engineering Selection Recommendations

Primary Recommendation: BK/MDL-5-R or MDL-5-R

Both BK/MDL-5-R and MDL-5-R are direct Eaton replacements with active product status. These parts maintain identical electrical and mechanical specifications to the obsolete BK/MDL-5. BK/MDL-5-R carries ROHS3 compliance and CE certification in addition to CSA and UL approvals. MDL-5-R also carries ROHS3 compliance and CE certification. Both are suitable for direct substitution without circuit modification.

Secondary Recommendation: BK/MDQ-5 or MDQ-5

The BK/MDQ-5 and MDQ-5 are parametric equivalents from Eaton's MDQ series. These parts maintain all critical electrical and mechanical parameters. BK/MDQ-5 and MDQ-5 carry CSA and UL approvals. These parts are suitable for applications where Eaton product continuity is required.

Alternative Recommendation: Littelfuse 0313005 Series

The Littelfuse 0313005 series (HXIDP, HXP, MXP, VXIDP, VXP) provides parametric equivalence with extended operating temperature range (-55°C to 125°C) and broader international certifications (CE, CSA, K-MARK, PSE, UL). All Littelfuse parts carry ROHS3 compliance. Selection among Littelfuse variants should be based on specific application requirements for melting I²t characteristics and operating temperature range.

Compliance Considerations:

BK/MDL-5 (original): RoHS non-compliant, CSA/UL approved
BK/MDL-5-R: ROHS3 compliant, CE/CSA/UL approved
MDL-5-R: ROHS3 compliant, CE/CSA/UL approved
BK/MDQ-5: RoHS non-compliant, CSA/UL approved
MDQ-5: RoHS non-compliant, CSA/UL approved
Littelfuse 0313005 series: ROHS3 compliant, CE/CSA/K-MARK/PSE/UL approved

For new designs or systems requiring RoHS3 compliance, select BK/MDL-5-R, MDL-5-R, or any Littelfuse 0313005 variant.

Frequently Asked Questions (FAQ)

Q: Can I use BK/MDL-5-R as a direct replacement for the obsolete BK/MDL-5?

A: Yes. BK/MDL-5-R maintains identical current rating (5 A), 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). The part is electrically and mechanically interchangeable.

Q: What is the difference between BK/MDL-5-R and MDL-5-R?

A: Both parts are functionally identical with matching electrical and mechanical specifications. The primary difference is packaging designation. Both are active Eaton products with ROHS3 compliance and CE/CSA/UL certifications.

Q: Can I substitute a Littelfuse 0313005 part for the Eaton BK/MDL-5?

A: Yes. All Littelfuse 0313005 variants (HXIDP, HXP, MXP, VXIDP, VXP) maintain the critical parameters: 5 A current rating, 250 V AC voltage rating, Slow Blow response, Cartridge Glass fuse type, 3AB/3AG package, and 0.250" x 1.250" dimensions. Littelfuse parts offer extended operating temperature range (-55°C to 125°C) and broader international certifications.

Q: What is the difference between Littelfuse 0313005.HXP and 0313005.MXP?

A: Both parts share identical electrical and mechanical specifications. The primary difference is the Melting I²t value: 0313005.HXP has 140 I²t, while 0313005.MXP has 276 I²t. Selection depends on application-specific thermal response requirements.

Q: Are all substitute parts RoHS compliant?

A: No. The original BK/MDL-5, BK/MDQ-5, and MDQ-5 are RoHS non-compliant. BK/MDL-5-R, MDL-5-R, and all Littelfuse 0313005 variants are ROHS3 compliant. For systems requiring RoHS3 compliance, select from the compliant alternatives.

Q: What certifications do these fuses carry?

A: Eaton MDL series (BK/MDL-5-R, MDL-5-R) carry CE, CSA, and UL certifications. Eaton MDQ series (BK/MDQ-5, MDQ-5) carry CSA and UL certifications. Littelfuse 0313005 series carry CE, CSA, K-MARK, PSE, and UL certifications.

Q: Can I use these fuses in any 3AB or 3AG holder?

A: Yes. All substitute parts are designed for use in standard 3AB and 3AG fuse holders. The 1/4" x 1-1/4" physical dimensions ensure mechanical compatibility with any holder rated for this package designation.

Q: What is the breaking capacity of these fuses?

A: All parts listed maintain a breaking capacity of 200 A at rated voltage (250 V AC).

Q: Are there inventory considerations for selecting a substitute?

A: Inventory levels vary by part number. BK/MDL-5-R (917 units), MDL-5-R (897 units), and Littelfuse 0313005.HXP (5083 units) show higher availability. Verify current inventory with your supplier before final part selection.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message