MJS 500 Equivalent & Substitute Parts

Part Overview

The MJS 500 is a 500 mA, 250 V AC/DC slow-blow glass cartridge fuse in 2AG package format (5mm x 15mm axial). Manufactured by Bel Fuse Inc., this component is classified as obsolete. Due to its obsolete status, identifying functionally equivalent active alternatives is essential for ongoing system maintenance and new design implementations. The MJS 500-R provides a direct functional equivalent with improved compliance characteristics.

Substiute Parts

MJS 500

Bel Fuse Inc.In Stock: 1182MJS 500 Datasheet

Current PartRFQ

MJS 500-R

Bel Fuse Inc.In Stock: 779MJS 500-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The MJS 500-R qualifies as a direct substitute based on the following critical parameters:

• Current Rating: 500 mA (identical)
• Voltage Rating (AC): 250 V (identical)
• Fuse Type: Cartridge, Glass (identical)
• Package / Case: 2AG, 5mm x 15mm (Axial) (identical)
• Response Time: Slow Blow (identical)
• Breaking Capacity @ Rated Voltage: 200 A (identical)
• Melting I²t: 2 (identical)
• Operating Temperature Range: -55°C ~ 125°C (identical)
• Mounting Type: Through Hole (identical)

The MJS 500-R maintains full electrical and mechanical compatibility with the original MJS 500, enabling direct replacement in existing applications.

Parameter Comparison

Engineering Selection Recommendations

The MJS 500-R is the appropriate selection for applications currently using the MJS 500. The substitute part maintains identical electrical and mechanical specifications across all critical parameters. The MJS 500-R offers the additional advantage of active product status, ensuring continued availability and supply chain reliability. The MJS 500-R also provides ROHS3 compliance, addressing regulatory requirements for new designs and systems subject to RoHS directives. The lower DC cold resistance (0.57 Ohms versus 0.84 Ohms) represents a minor improvement in electrical characteristics without affecting functional compatibility.

Frequently Asked Questions (FAQ)

Q: Can the MJS 500-R be used as a direct replacement for the MJS 500?

A: Yes. The MJS 500-R is electrically and mechanically identical to the MJS 500 across all specified parameters, including current rating, voltage rating, response time, package format, and operating temperature range. Direct substitution is supported.

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

A: The MJS 500 has a DC cold resistance of 0.84 Ohms, while the MJS 500-R has 0.57 Ohms. This difference does not affect functional compatibility or circuit performance in standard fuse applications.

Q: Why is the MJS 500 listed as obsolete?

A: The MJS 500 has been discontinued by the manufacturer. The MJS 500-R is the active equivalent and should be used for new designs and ongoing system maintenance.

Q: Are there compliance differences between the two parts?

A: The MJS 500 is RoHS non-compliant, while the MJS 500-R is ROHS3 compliant. Both parts carry CE, CSA, and UL-based certifications. The MJS 500-R is recommended for applications subject to RoHS regulatory requirements.

Q: Is the 2AG package format the same for both parts?

A: Yes. Both the MJS 500 and MJS 500-R use the 2AG package format with identical dimensions of 5mm x 15mm (axial), ensuring mechanical compatibility in existing through-hole mounting applications.