Equivalent & Substitute Parts for 3AB 7-R Ceramic Fuse

Part Overview

The 3AB 7-R is a 7 A, 250 V AC ceramic cartridge fuse manufactured by Bel Fuse Inc. This fast-blow fuse is designed for applications requiring reliable overcurrent protection in AC circuits. The part is currently active in production with 1452 units in stock. Substitute parts are identified to provide alternative sourcing options while maintaining electrical and mechanical compatibility within the 3AB, 3AG form factor.

Substiute Parts

3AB 7-R

Bel Fuse Inc.In Stock: 14763AB 7-R Datasheet

Current PartRFQ

0314007.MXP

Littelfuse Inc.In Stock: 20310314007.MXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3AB 7-R is determined by the following mandatory parameters:

• Current Rating: 7 A (exact match required)
• Voltage Rating - AC: 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Requires Holder (exact match required)

The substitute part 0314007.MXP (Littelfuse Inc., Series 314) meets all mandatory electrical and mechanical parameters. This part provides equivalent functionality with additional DC voltage rating capability (125 V DC) and enhanced breaking capacity specifications.

Parameter Comparison

Engineering Selection Recommendations

Both the 3AB 7-R and 0314007.MXP are active production parts with full regulatory compliance. Selection between these parts should be based on application requirements:

The 3AB 7-R is suitable for AC-only applications requiring 250 V protection with a breaking capacity of 200 A at rated voltage.

The 0314007.MXP provides expanded capability with dual AC/DC voltage ratings (250 V AC, 125 V DC) and significantly higher breaking capacity (750 A AC, 10 kA DC). This part is appropriate for applications requiring DC circuit protection or higher fault current withstand capability. The lower melting I²t value (71 versus 141) indicates faster thermal response characteristics.

Both parts carry equivalent regulatory approvals (CE, CSA, PSE) with the 0314007.MXP offering additional K-MARK and UL certifications. Both are ROHS3 compliant and REACH unaffected.

Frequently Asked Questions (FAQ)

Q: Can 0314007.MXP be used as a direct replacement for 3AB 7-R in all applications?

A: Yes, for AC-only circuits at 250 V with 7 A current requirements. Both parts share identical current rating, AC voltage rating, fuse type, response time, and package dimensions. The substitute part offers additional DC voltage capability and higher breaking capacity, which do not negatively impact AC-only applications.

Q: What is the significance of the different melting I²t values (141 versus 71)?

A: The melting I²t parameter defines the thermal energy required to melt the fuse element. The 0314007.MXP has a lower I²t value, indicating faster thermal response to overcurrent conditions. This difference reflects different fuse element designs but does not affect compatibility in applications designed for 7 A fast-blow protection.

Q: Are both parts compatible with the same holder?

A: Yes. Both parts use the 3AB, 3AG form factor with identical physical dimensions (1/4" Dia x 1-1/4" L). Both require a compatible fuse holder and are not panel-mount components.

Q: What is the difference in DC cold resistance between these parts?

A: The 3AB 7-R has 0.013 Ohms while 0314007.MXP has 0.0187 Ohms. This difference reflects different internal conductor materials or designs. For AC applications, this parameter has minimal impact on circuit performance.

Q: Which part should be selected for new designs?

A: For new designs, 0314007.MXP is recommended due to its broader voltage rating capability (AC and DC), higher breaking capacity, and expanded regulatory approvals (K-MARK, UL). This provides greater application flexibility without compromising AC-only performance.