Littelfuse 0312012.MXP Glass Cartridge Fuse 12A 32VAC Equivalent & Substitute Parts

Part Overview

The Littelfuse 0312012.MXP is a 12 A, 32 V AC/DC fast-blow glass cartridge fuse in 3AB/3AG package format (1/4" × 1-1/4"). This component is classified as Active product status and is designed for applications requiring reliable overcurrent protection in low-voltage circuits. Substitute parts are identified when equivalent electrical and mechanical parameters align with the original specification, enabling direct replacement without circuit redesign.

Substiute Parts

0312012.MXP

Littelfuse Inc.In Stock: 7290312012.MXP Datasheet

Current PartRFQ

0312012.HXP

Littelfuse Inc.In Stock: 11720312012.HXP Datasheet

Parametric EquivalentRFQ

3AG 12-R

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

MFR RecommendedRFQ

BK/AGC-12-R

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

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0312012.MXP are classified into two categories based on electrical parameter alignment:

Parametric Equivalents (Direct Substitutes):

• Parts matching all critical electrical parameters: 12 A current rating, 32 V AC voltage rating, fast-blow response, 3AB/3AG package, and identical physical dimensions (0.250" Dia × 1.250" L)
• These parts maintain the same breaking capacity and thermal characteristics within acceptable engineering tolerances
• Qualifying parts: 0312012.HXP (Littelfuse), BK/AGC-12-R (Eaton)

Manufacturer Recommended Equivalent (Voltage-Rated Substitute):

• Parts with matching current rating (12 A) and package format but elevated voltage rating (125 V AC vs. 32 V AC)
• Suitable for applications where the circuit voltage is lower than or equal to the substitute's rating
• Qualifying part: 3AG 12-R (Bel Fuse Inc.)

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Parametric Equivalents):

• 0312012.HXP (Littelfuse) and BK/AGC-12-R (Eaton) are electrically and mechanically equivalent to the 0312012.MXP
• Both maintain identical current rating, voltage rating, response time, and physical dimensions
• All three parts hold ROHS3 compliance and appropriate regulatory certifications (CSA, UL/cULus)
• Selection between these options depends on availability and supply chain requirements

For Voltage-Rated Substitution:

• 3AG 12-R (Bel Fuse Inc.) is suitable for circuits operating at or below 32 V AC, despite its 125 V AC rating
• This part provides higher breaking capacity (10 kA) and broader regulatory approval (CE, CSA, cURus, PSE)
• Use this substitute only when circuit voltage does not exceed the original 0312012.MXP specification of 32 V AC
• The elevated melting I²t (501 vs. 234.6) indicates different thermal response characteristics; verify compatibility with circuit protection requirements

Frequently Asked Questions (FAQ)

Q: Can I use the 3AG 12-R (Bel Fuse) as a direct replacement for the 0312012.MXP? A: The 3AG 12-R is mechanically compatible and shares the same 12 A current rating and 3AB/3AG package format. However, its 125 V AC rating exceeds the original 32 V AC specification. Use this substitute only if your circuit voltage is 32 V AC or lower. The higher breaking capacity and melting I²t differ from the original; confirm these characteristics align with your circuit protection design.

Q: What is the difference between the 0312012.MXP and 0312012.HXP? A: Both parts are manufactured by Littelfuse and are parametric equivalents with identical electrical and mechanical specifications: 12 A, 32 V AC, fast-blow response, 3AB/3AG package, and -55°C to 125°C operating range. The primary difference is inventory availability and internal manufacturing variant designation (MXP vs. HXP).

Q: Are all substitute parts ROHS3 compliant? A: Yes. The 0312012.MXP, 0312012.HXP, 3AG 12-R, and BK/AGC-12-R are all ROHS3 compliant and suitable for applications requiring environmental compliance.

Q: Does the physical dimension difference in the 3AG 12-R (1.252" vs. 1.250" length) affect compatibility? A: The 0.002" (0.05mm) length difference is within standard mechanical tolerance for 3AB/3AG fuse holders and does not affect physical fit or electrical performance.

Q: Which substitute offers the highest breaking capacity? A: The 3AG 12-R (Bel Fuse) provides 10 kA breaking capacity, compared to 300 A for the 0312012.MXP and 0312012.HXP, and 1 kA for the BK/AGC-12-R. Select based on your circuit's maximum fault current requirements.