MDA-1-1/4-R Equivalent & Substitute Parts

Part Overview

The MDA-1-1/4-R is a 1.25 A, 250 V AC ceramic cartridge fuse manufactured by Eaton - Electronics Division. This component is designed for circuits requiring slow-blow fuse protection in standard 3AB/3AG holder configurations. The part is currently active in production with 646 pieces in stock. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and application-specific requirements where alternative electrical or mechanical characteristics may be acceptable within system design parameters.

Substiute Parts

MDA-1-1/4-R

Eaton - Electronics DivisionIn Stock: 754MDA-1-1/4-R Datasheet

Current PartRFQ

BK/MDA-1-1/4-R

Eaton - Electronics DivisionIn Stock: 1009BK/MDA-1-1/4-R Datasheet

Parametric EquivalentRFQ

0001.2525

SCHURTER Inc.In Stock: 12940001.2525 Datasheet

DirectRFQ

03261.25HXP

Littelfuse Inc.In Stock: 127003261.25HXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MDA-1-1/4-R is determined by the following critical parameters:

Primary Matching Criteria:

• Current Rating: 1.25 A (exact match required)
• Voltage Rating - AC: 250 V (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required for holder compatibility)
• Mounting Type: Requires Holder (exact match required)
• Response Time: Slow Blow (exact match required)

Secondary Compatibility Factors:

• Fuse Type: Ceramic or Glass construction acceptable within same electrical ratings
• Size / Dimension: Tolerance within 0.250" Dia x 1.250" L specification
• RoHS Status: ROHS3 Compliant (maintained across all substitutes)

Substitute parts are grouped into two categories: parametric equivalents (identical electrical and mechanical specifications) and direct manufacturer alternatives (same functional performance with acceptable variations in secondary parameters such as DC voltage rating, melting I²t, or approval agencies).

Parameter Comparison

Engineering Selection Recommendations

BK/MDA-1-1/4-R (Eaton - Electronics Division)

This part is a parametric equivalent to the MDA-1-1/4-R with identical electrical and mechanical specifications. Both are ceramic cartridge fuses with 1.25 A current rating, 250 V AC voltage rating, and 3AB/3AG package compatibility. The BK/MDA-1-1/4-R maintains ROHS3 compliance and active product status. Selection between MDA-1-1/4-R and BK/MDA-1-1/4-R is based on inventory availability and procurement lead time, as both parts are functionally interchangeable. The BK/MDA-1-1/4-R currently has higher inventory (931 pieces versus 646 pieces).

0001.2525 (SCHURTER Inc.)

This part is a direct manufacturer alternative with matching current rating (1.25 A), AC voltage rating (250 V), and package configuration (3AB, 3AG, 1/4" x 1-1/4"). The primary difference is fuse construction: 0001.2525 is a glass cartridge fuse versus the ceramic construction of MDA-1-1/4-R. Both maintain slow-blow response time and ROHS3 compliance. The 0001.2525 includes DC voltage rating (63 V) and operating temperature range (-40°C ~ 85°C), which are not specified for the MDA-1-1/4-R. Approval agency is cURus (versus CE, CSA, UL for MDA-1-1/4-R). Selection of 0001.2525 is appropriate where glass fuse construction is acceptable and DC circuit protection to 63 V is required.

03261.25HXP (Littelfuse Inc.)

This part is a direct manufacturer alternative with matching current rating (1.25 A), AC voltage rating (250 V), and package configuration (3AB, 3AG, 1/4" x 1-1/4"). Both are ceramic cartridge fuses with slow-blow response. The 03261.25HXP provides extended DC voltage rating (125 V versus unspecified for MDA-1-1/4-R) and wider operating temperature range (-55°C ~ 125°C). Approval agencies include CE, CSA, PSE, and UL. The melting I²t value (24) is significantly higher than MDA-1-1/4-R (1.5), indicating different thermal response characteristics. Selection of 03261.25HXP is appropriate for applications requiring higher DC voltage protection, extended temperature operation, or PSE certification.

Frequently Asked Questions (FAQ)

Q: Can BK/MDA-1-1/4-R be used as a direct replacement for MDA-1-1/4-R?

A: Yes. BK/MDA-1-1/4-R is a parametric equivalent with identical current rating (1.25 A), voltage rating (250 V AC), fuse type (ceramic cartridge), response time (slow blow), and package configuration (3AB, 3AG, 1/4" x 1-1/4"). Both parts are manufactured by Eaton - Electronics Division and maintain ROHS3 compliance. No circuit redesign or holder modification is required.

Q: What is the difference between ceramic and glass fuse construction in the 0001.2525?

A: The MDA-1-1/4-R uses ceramic cartridge construction, while the 0001.2525 uses glass cartridge construction. Both are slow-blow fuses with identical current (1.25 A) and AC voltage (250 V) ratings and fit the same 3AB/3AG holders. The material difference affects internal arc suppression characteristics and melting I²t values (1.5 for ceramic versus 2.5 for glass). Selection between ceramic and glass depends on application-specific arc suppression requirements and circuit protection characteristics.

Q: Is the 03261.25HXP suitable for DC circuit applications?

A: The 03261.25HXP has a DC voltage rating of 125 V, making it suitable for DC circuits up to 125 V. The MDA-1-1/4-R does not specify a DC voltage rating. If the application requires DC circuit protection, the 03261.25HXP is the appropriate selection among the three substitutes. The 0001.2525 has a lower DC rating (63 V) and should be selected only if DC protection to 63 V is sufficient.

Q: Are all substitute parts compatible with existing 3AB/3AG fuse holders?

A: Yes. All substitute parts (BK/MDA-1-1/4-R, 0001.2525, and 03261.25HXP) use the 3AB/3AG package configuration with dimensions 0.250" Dia x 1.250" L (or 1.252" L for 0001.2525, within tolerance). All parts fit standard 3AB/3AG fuse holders without modification. No holder replacement is required when substituting between these parts.

Q: What approval agencies certify each substitute part?

A: MDA-1-1/4-R and BK/MDA-1-1/4-R carry CE, CSA, and UL approvals (BK variant does not specify approval agencies in documentation). The 0001.2525 carries cURus approval. The 03261.25HXP carries CE, CSA, PSE, and UL approvals. Selection should consider regional regulatory requirements and end-application certification needs.

Q: What is the significance of the melting I²t parameter difference?

A: Melting I²t indicates the thermal energy required to melt the fuse element. MDA-1-1/4-R and BK/MDA-1-1/4-R have melting I²t of 1.5, 0001.2525 has 2.5, and 03261.25HXP has 24. Higher melting I²t values indicate slower thermal response and greater tolerance to transient overcurrent conditions. Selection depends on circuit inrush current characteristics and protection coordination requirements.

Q: Can these fuses be used interchangeably in the same circuit?

A: All substitute parts share identical current rating (1.25 A), AC voltage rating (250 V), response time (slow blow), and package configuration. They are mechanically and electrically compatible for AC circuits rated 250 V or lower. For DC applications, verify that the selected part's DC voltage rating meets circuit requirements. For applications with specific thermal response or approval agency requirements, confirm that the substitute part's melting I²t and certifications align with system design specifications.