3SB 500 Equivalent & Substitute Parts

Part Overview

The 3SB 500 is a 500 mA, 250 V AC/DC glass cartridge fuse manufactured by Bel Fuse Inc. with slow-blow response characteristics. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new designs. The 3SB 500 requires a compatible holder (3AB or 3AG type) for installation and operates across a temperature range of -55°C to 125°C.

Substiute Parts

3SB 500

Bel Fuse Inc.In Stock: 7713SB 500 Datasheet

Current PartRFQ

3SB 500-R

Bel Fuse Inc.In Stock: 20043SB 500-R Datasheet

DirectRFQ

0313.500HXP

Littelfuse Inc.In Stock: 23640313.500HXP Datasheet

DirectRFQ

0313.500MXP

Littelfuse Inc.In Stock: 49370313.500MXP Datasheet

DirectRFQ

0313.500VXP

Littelfuse Inc.In Stock: 10450313.500VXP Datasheet

DirectRFQ

0313.500VXIDP

Littelfuse Inc.In Stock: 10550313.500VXIDP Datasheet

SimilarRFQ

TSA-500MA

OptiFuseIn Stock: 885TSA-500MA Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 3SB 500 is determined by strict equivalence across the following critical parameters:

• Current Rating: 500 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)

All substitute parts listed below meet these electrical and mechanical parameters. Differences in secondary characteristics such as breaking capacity, melting I²t, DC cold resistance, and RoHS compliance status do not disqualify substitution but are documented for engineering reference.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts meet the critical electrical and mechanical parameters required for direct substitution with the obsolete 3SB 500. Selection should be based on the following factors:

Active Product Status: The 3SB 500-R (Bel Fuse Inc.), 0314.600HXP, 0314.600MXP, 0314.600VXP, 0314.600VXIDP (Littelfuse Inc.), and TSA-500MA (OptiFuse) are all active products with current manufacturing support and availability.

Compliance and Certifications: The 3SB 500-R, all Littelfuse 0313 series variants, and TSA-500MA are ROHS3 compliant, addressing modern regulatory requirements. The original 3SB 500 is RoHS non-compliant. All substitute parts maintain the required approval agencies (CE, CSA, UL or equivalent).

Dimensional Compatibility: All parts fit the 3AB and 3AG holder packages. Minor dimensional variations (0.250" Dia x 1.250" L versus 0.250" Dia x 1.252" L) are within tolerance for holder compatibility.

Manufacturer Availability: Littelfuse 0313 series parts (0314.600MXP, 0314.600HXP, 0314.600VXP, 0314.600VXIDP) show the highest inventory levels (976–4917 units), followed by 3SB 500-R (1898 units) and TSA-500MA (827 units).

Frequently Asked Questions (FAQ)

Q: Can I use any of these substitute parts interchangeably with the 3SB 500?

A: Yes. All listed parts meet the critical substitution parameters: 500 mA current rating, 250 V AC voltage rating, slow-blow response, cartridge glass fuse type, and 3AB/3AG package compatibility. They are electrically and mechanically equivalent for the 3SB 500 application.

Q: What is the difference between the 3SB 500 and 3SB 500-R?

A: Both are manufactured by Bel Fuse Inc. and share identical electrical specifications. The primary differences are: 3SB 500-R is active (versus obsolete), ROHS3 compliant (versus non-compliant), has higher breaking capacity (200A versus 35A), lower DC cold resistance (1.4 Ohms versus 1.7 Ohms), and is available in bulk packaging with higher inventory.

Q: Are Littelfuse 0313 series parts (0314.600HXP, 0314.600MXP, 0314.600VXP, 0314.600VXIDP) interchangeable?

A: Yes. All four Littelfuse variants meet identical electrical and mechanical parameters. Differences in part number suffixes (HXP, MXP, VXP, VXIDP) reflect internal manufacturing or packaging designations but do not affect functional equivalence for the 3SB 500 application.

Q: What is the significance of the breaking capacity difference between parts?

A: Breaking capacity indicates the maximum fault current the fuse can safely interrupt. The 3SB 500 and Littelfuse variants have 35A breaking capacity, while 3SB 500-R has 200A and TSA-500MA has 100A. All exceed typical circuit protection requirements for 500 mA fuses. Selection should align with the specific circuit's maximum fault current rating.

Q: Are all substitute parts ROHS3 compliant?

A: The 3SB 500-R, all Littelfuse 0313 series parts, and TSA-500MA are ROHS3 compliant. The original 3SB 500 is RoHS non-compliant. For applications requiring RoHS compliance, use any of the active substitute parts listed.

Q: Will these fuses fit my existing 3AB and 3AG holders?

A: Yes. All substitute parts are designed for 3AB and 3AG holder packages. Dimensional specifications (0.250" diameter, 1.250"–1.252" length) are within the tolerance range for these standard holders.

Q: Which substitute part should I choose for new designs?

A: For new designs, select from active products with current manufacturing support: 3SB 500-R, Littelfuse 0313 series (0314.600HXP, 0314.600MXP, 0314.600VXP, 0314.600VXIDP), or TSA-500MA. All meet modern compliance requirements and have established supply chains.