Littelfuse 0311012.H Glass Fuse 12A 32VAC 3AB 3AG Equivalent & Substitute Parts

Part Overview

The Littelfuse 0311012.H is a 12 A, 32 V AC/DC fast-blow glass cartridge fuse in 3AB/3AG form factor (1/4" x 1-1/4"). This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new designs. The fuse requires a compatible holder for installation and is designed for general-purpose circuit protection applications requiring fast response characteristics.

Substiute Parts

0311012.H

Littelfuse Inc.In Stock: 11900311012.H Datasheet

Current PartRFQ

0312012.HXP

Littelfuse Inc.In Stock: 11720312012.HXP Datasheet

Parametric EquivalentRFQ

0312012.MXP

Littelfuse Inc.In Stock: 7290312012.MXP Datasheet

Parametric EquivalentRFQ

0312012.VXP

Littelfuse Inc.In Stock: 8220312012.VXP Datasheet

Parametric EquivalentRFQ

BK/AGC-12-R

Eaton - Electronics DivisionIn Stock: 5282BK/AGC-12-R Datasheet

DirectRFQ

3AG 12-R

Bel Fuse Inc.In Stock: 26833AG 12-R Datasheet

MFR RecommendedRFQ

AGC-12-R

Eaton - Electronics DivisionIn Stock: 759AGC-12-R Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 0311012.H is determined by strict equivalence across the following parameters:

• Current Rating: 12 A (exact match required)
• Voltage Rating (AC): 32 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
• Mounting Type: Requires Holder (exact match required)

Substitute parts are grouped into three categories based on manufacturer and product status:

Parametric Equivalents (Littelfuse 312 Series): Parts 0312012.HXP, 0312012.MXP, and 0312012.VXP maintain all critical electrical and mechanical parameters while offering active product status and improved compliance certifications.

Direct Manufacturer Equivalent (Eaton): Parts BK/AGC-12-R and AGC-12-R from Eaton Electronics Division provide identical electrical and mechanical specifications with active availability.

Manufacturer Recommended Equivalent (Bel Fuse): Part 3AG 12-R from Bel Fuse Inc. meets all mechanical and electrical requirements but operates at a higher voltage rating (125 V AC), making it suitable for applications where the 32 V specification is not a limiting constraint.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (32 V AC Requirement):

The Littelfuse 312 series parts (0312012.HXP, 0312012.MXP, 0312012.VXP) provide the most direct substitution path. All three maintain the 32 V AC voltage specification and offer active product status with ROHS3 compliance. Selection among these three variants depends on packaging requirements and inventory availability. The Eaton AGC-12-R and BK/AGC-12-R parts also maintain 32 V AC specification with active status and provide higher breaking capacity (1kA vs. 300A).

For Applications with Higher Voltage Tolerance:

The Bel Fuse 3AG 12-R operates at 125 V AC, providing a higher voltage margin. This part is suitable only for applications where the circuit voltage does not exceed 125 V AC and where the higher voltage rating does not create design conflicts. This part offers the highest breaking capacity (10kA) and broader international certifications (CE, CSA, cURus, PSE).

Compliance Considerations:

All active substitute parts are ROHS3 compliant, addressing the RoHS non-compliance status of the obsolete 0311012.H. The Littelfuse 312 series and Eaton parts carry CSA and UL certifications matching or exceeding the original part's approval agencies. The Bel Fuse part adds CE and PSE certifications for broader geographic applicability.

Frequently Asked Questions (FAQ)

Q: Can I use the Bel Fuse 3AG 12-R as a direct replacement for the 0311012.H?

A: The 3AG 12-R is mechanically and electrically compatible in terms of current rating, response time, and physical dimensions. However, it operates at 125 V AC versus the original 32 V AC specification. Use this part only if your circuit voltage does not exceed 125 V AC and if the higher voltage rating does not conflict with system design requirements.

Q: What is the difference between the three Littelfuse 312 series substitutes (0312012.HXP, 0312012.MXP, 0312012.VXP)?

A: All three parts are parametrically equivalent with identical electrical specifications (12 A, 32 V AC, Fast Blow, 300A breaking capacity). The differences are in packaging designation and internal construction variants. Selection should be based on packaging availability and inventory status.

Q: Are the Eaton AGC-12-R and BK/AGC-12-R interchangeable?

A: Yes. Both parts are from Eaton Electronics Division, maintain identical electrical and mechanical specifications (12 A, 32 V AC, 1kA breaking capacity), and carry the same certifications. The BK prefix indicates a specific packaging or distribution variant. Selection depends on part availability and procurement channels.

Q: Does the higher breaking capacity of substitute parts affect compatibility?

A: No. Higher breaking capacity (1kA for Eaton parts, 10kA for Bel Fuse) indicates improved fault protection capability and does not create compatibility issues. The fuse will still operate at the specified 12 A current rating and 32 V AC voltage rating.

Q: What certifications should I verify for my application?

A: The original 0311012.H carries CSA and UL certifications. All active substitutes maintain these certifications or equivalent. If your application requires specific regional certifications (CE, PSE, cURus), the Bel Fuse 3AG 12-R provides the broadest certification coverage.

Q: Can I mix different substitute parts in the same system?

A: Yes, provided all parts meet your circuit voltage and current requirements. However, for consistency and simplified inventory management, standardizing on a single substitute part number is recommended.