Equivalent & Substitute Parts for 3AB 500-R Ceramic Fuse

Part Overview

The 3AB 500-R is an active ceramic fuse cartridge manufactured by Bel Fuse Inc., rated for 500 mA at 250 V AC with fast-blow response characteristics. This component is designed for applications requiring reliable overcurrent protection in AC circuits with standard 3AB, 3AG holder compatibility. Substitute parts are identified to provide equivalent functional performance where the original part is unavailable or where specific voltage or resistance requirements necessitate alternative selection.

Substiute Parts

3AB 500-R

Bel Fuse Inc.In Stock: 13903AB 500-R Datasheet

Current PartRFQ

0314.500MXP

Littelfuse Inc.In Stock: 7350314.500MXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3AB 500-R is determined by the following critical parameters:

• Current Rating: Must be 500 mA
• Voltage Rating - AC: Must be 250 V minimum
• Fuse Type: Must be Cartridge, Ceramic
• Response Time: Must be Fast Blow
• Package / Case: Must be 3AB, 3AG, 1/4" x 1-1/4" compatible
• Breaking Capacity: Must be 35A or greater at rated voltage
• Operating Temperature: Must support -55°C ~ 125°C range
• Compliance: Must maintain ROHS3 compliance and relevant approval agencies (CE, CSA, cURus or equivalent)

The substitute part 0314.500MXP from Littelfuse Inc. meets all critical substitution criteria. This part maintains identical current rating, AC voltage rating, fuse type, response time, and physical package specifications. Additional DC voltage capability (125 V DC) and enhanced breaking capacity (10kA DC) represent extended functionality without compromising AC circuit protection performance.

Parameter Comparison

Engineering Selection Recommendations

Both the 3AB 500-R and 0314.500MXP are active products with full regulatory compliance. Selection between these parts is based on application-specific requirements:

3AB 500-R is appropriate for AC-only circuit protection applications where the specified parameters are sufficient and Bel Fuse Inc. supply chain preference exists.

0314.500MXP is appropriate for applications requiring dual AC/DC voltage capability, lower DC cold resistance (0.5 Ohms vs. 1.19 Ohms), or where Littelfuse Inc. supply chain availability is preferred. The lower melting I²t value (0.115 vs. 0.14) indicates faster thermal response characteristics. UL approval certification provides additional regulatory coverage in North American markets.

Both parts maintain identical AC protection performance and physical compatibility with 3AB, 3AG holders.

Frequently Asked Questions (FAQ)

Q: Can 0314.500MXP be used as a direct replacement for 3AB 500-R in AC circuits?

A: Yes. Both parts share identical current rating (500 mA), AC voltage rating (250 V), fuse type (Cartridge, Ceramic), response time (Fast Blow), and physical package dimensions (3AB, 3AG, 1/4" x 1-1/4"). AC circuit protection performance is equivalent.

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

A: The 3AB 500-R has 1.19 Ohms DC cold resistance, while the 0314.500MXP has 0.5 Ohms. Lower resistance reduces voltage drop across the fuse element during normal operation. Selection depends on circuit design requirements for voltage drop tolerance.

Q: Are both parts physically compatible with existing 3AB, 3AG holders?

A: Yes. Both parts conform to the 3AB, 3AG, 1/4" x 1-1/4" package specification and are mechanically compatible with standard holders designed for this form factor.

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

A: The 0314.500MXP has a lower melting I²t value (0.115 vs. 0.14), indicating faster thermal response to overcurrent conditions. This represents a tighter thermal characteristic and may be relevant for applications with specific transient protection requirements.

Q: Does 0314.500MXP provide DC voltage protection?

A: Yes. The 0314.500MXP is rated for 125 V DC in addition to 250 V AC. The 3AB 500-R does not specify DC voltage capability. If DC circuit protection is required, 0314.500MXP is the appropriate selection.

Q: Are both parts RoHS compliant?

A: Yes. Both the 3AB 500-R and 0314.500MXP are ROHS3 compliant and REACH unaffected.