Equivalent & Substitute Parts for BK/AGC-3/4 Glass Cartridge Fuse

Part Overview

The BK/AGC-3/4 is a 750 mA, 250 V AC/DC fast-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 (6.35 mm × 31.75 mm). The main part number is currently classified as obsolete, necessitating identification of active equivalent and substitute components that maintain identical electrical and mechanical specifications for continued circuit protection applications.

Substiute Parts

BK/AGC-3/4

Eaton - Electronics DivisionIn Stock: 835BK/AGC-3/4 Datasheet

Current PartRFQ

AGC-3/4-R

Eaton - Electronics DivisionIn Stock: 1182AGC-3/4-R Datasheet

DirectRFQ

BK/AGC-3/4-R

Eaton - Electronics DivisionIn Stock: 8343BK/AGC-3/4-R Datasheet

DirectRFQ

BK/AGC-3/4WW-R

Eaton - Electronics DivisionIn Stock: 800BK/AGC-3/4WW-R Datasheet

Parametric EquivalentRFQ

0312.750MXP

Littelfuse Inc.In Stock: 16300312.750MXP Datasheet

SimilarRFQ

0312.750VXP

Littelfuse Inc.In Stock: 9180312.750VXP Datasheet

SimilarRFQ

0312.750HXP

Littelfuse Inc.In Stock: 13200312.750HXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BK/AGC-3/4 is determined by strict equivalence across the following critical parameters:

Electrical Parameters:

• Current Rating: 750 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity: 35 A @ rated voltage (exact match required)

Mechanical Parameters:

• Package / Case: 3AB, 3AG form factor (exact match required)
• Physical Dimensions: 0.250" diameter × 1.250" length (exact match required)
• Mounting Type: Requires Holder (exact match required)

Compliance Parameters:

• Approval Agencies: CSA and UL certifications (minimum requirement)
• Operating Temperature: -55°C to 125°C (exact match required)

All substitute parts listed maintain these parameters without deviation. Substitutes are categorized as Direct Manufacturer equivalents (same manufacturer, active status) and Parametric Equivalents (alternative manufacturers, identical electrical and mechanical specifications).

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: BK/AGC-3/4-R

The BK/AGC-3/4-R is the direct manufacturer equivalent from Eaton Electronics Division. This part maintains identical electrical and mechanical specifications to the obsolete BK/AGC-3/4, including melting I²t of 1.716 and DC cold resistance of 0.272 Ω. The part is active in production with 8,288 units in stock. RoHS3 compliance and REACH unaffected status provide regulatory alignment for current applications.

Secondary Recommendation: AGC-3/4-R

The AGC-3/4-R is an active Eaton Electronics equivalent with identical performance parameters. This part carries RoHS compliance certification and maintains the same electrical characteristics as the main part. Inventory availability is 1,101 units.

Tertiary Recommendation: BK/AGC-3/4WW-R

The BK/AGC-3/4WW-R is an active parametric equivalent from Eaton Electronics with identical electrical and mechanical specifications. This variant is available with 705 units in stock and provides an alternative within the same manufacturer family.

Cross-Manufacturer Alternatives: Littelfuse 0312 Series

The Littelfuse 0312.750MXP, 0312.750VXP, and 0312.750HXP are parametric equivalents that maintain all critical electrical and mechanical parameters. These parts carry CE, CSA, and UL certifications. Minor variations exist in melting I²t (1.84 versus 1.716) and DC cold resistance (0.2445 Ω versus 0.272 Ω), which remain within acceptable tolerance for equivalent circuit protection performance. All three Littelfuse variants are active with inventory availability ranging from 822 to 1,600 units.

Frequently Asked Questions (FAQ)

Q: Can I use BK/AGC-3/4-R as a direct replacement for the obsolete BK/AGC-3/4?

A: Yes. The BK/AGC-3/4-R is a direct manufacturer equivalent with identical current rating (750 mA), voltage rating (250 V AC), response time (fast blow), breaking capacity (35 A), physical dimensions (0.250" × 1.250"), and package type (3AB, 3AG). Both parts require the same holder and operate across the same temperature range (-55°C to 125°C).

Q: What is the difference between the Eaton and Littelfuse substitute options?

A: All substitute parts maintain identical current rating, voltage rating, response time, breaking capacity, physical dimensions, and package specifications. The Littelfuse 0312 series parts differ in melting I²t (1.84 versus 1.716) and DC cold resistance (0.2445 Ω versus 0.272 Ω). Both manufacturers hold CSA and UL certifications. Selection between manufacturers depends on supply chain requirements and existing inventory management practices.

Q: Are the Littelfuse 0312.750MXP, 0312.750VXP, and 0312.750HXP parts interchangeable with each other?

A: Yes. All three Littelfuse variants maintain identical electrical and mechanical specifications, including current rating, voltage rating, response time, breaking capacity, dimensions, and package type. They are parametric equivalents suitable for the same circuit protection applications.

Q: Do all substitute parts fit the same 3AB and 3AG holders?

A: Yes. All substitute parts maintain the identical 0.250" diameter by 1.250" length physical specification and 3AB, 3AG package designation. All parts require the same holder type and are mechanically interchangeable.

Q: What certifications do the substitute parts carry?

A: Eaton parts (BK/AGC-3/4-R, AGC-3/4-R, BK/AGC-3/4WW-R) carry CSA and UL certifications. Littelfuse parts (0312.750MXP, 0312.750VXP, 0312.750HXP) carry CE, CSA, and UL certifications. All parts meet the minimum approval agency requirements for the original BK/AGC-3/4.

Q: Is RoHS compliance a factor in selecting a substitute?

A: The original BK/AGC-3/4 is RoHS non-compliant. All active substitute parts (BK/AGC-3/4-R, AGC-3/4-R, BK/AGC-3/4WW-R, and all Littelfuse 0312 variants) are RoHS3 compliant, providing regulatory alignment for current manufacturing and procurement standards.