MJS 2 Equivalent & Substitute Parts

Part Overview

The MJS 2 is a 2A 250VAC glass cartridge fuse in 2AG package format (5mm x 15mm axial), manufactured by Bel Fuse Inc. This through-hole mounted slow-blow fuse is designed for circuit protection applications requiring moderate current ratings and AC/DC voltage tolerance. The main part (MJS 2) carries an obsolete product status, making identification of active equivalent parts essential for ongoing procurement and system maintenance.

Substiute Parts

MJS 2

Bel Fuse Inc.In Stock: 799MJS 2 Datasheet

Current PartRFQ

MJS 2-R

Bel Fuse Inc.In Stock: 967MJS 2-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete MJS 2 with the MJS 2-R is based on strict equivalence across all critical electrical and mechanical parameters:

• Current Rating: Both parts rated at 2 A
• Voltage Rating: Both rated at 250 V AC
• Fuse Characteristics: Both are slow-blow glass cartridge fuses
• Physical Package: Both use 2AG format (5mm x 15mm axial)
• Mounting Configuration: Both are through-hole mounted
• Breaking Capacity: Both rated at 200A @ rated voltage
• Thermal Performance: Both operate across -55°C ~ 125°C range
• Melting I²t: Both specified at 23

The MJS 2-R represents the active production equivalent with identical functional and dimensional specifications, differing only in packaging format (bulk vs. standard) and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

The MJS 2-R is the direct active equivalent for the obsolete MJS 2. Selection should be based on the following factors:

Product Status: The MJS 2 is obsolete and no longer in active production. The MJS 2-R maintains identical electrical and mechanical specifications while carrying active product status, ensuring long-term availability and supply chain continuity.

Regulatory Compliance: The MJS 2-R includes cULus certification (combined UL and CSA approval) versus separate UL and CSA certifications on the MJS 2. The MJS 2-R is ROHS3 compliant, addressing modern environmental and regulatory requirements, whereas the original MJS 2 is non-compliant.

Functional Equivalence: Both parts are electrically and mechanically identical across all critical parameters including current rating, voltage rating, response time, package format, and thermal operating range. Direct substitution is supported without circuit redesign.

DC Cold Resistance Variance: The MJS 2-R exhibits lower DC cold resistance (0.064 Ohms) compared to the MJS 2 (0.094 Ohms). This difference does not affect circuit protection performance and represents normal manufacturing variation within acceptable tolerances for this component class.

Frequently Asked Questions (FAQ)

Q: Can MJS 2-R be used as a direct replacement for MJS 2 in existing designs?

A: Yes. The MJS 2-R is electrically and mechanically equivalent to the MJS 2 across all critical parameters. Both are 2A 250VAC slow-blow glass cartridge fuses in 2AG package format with identical breaking capacity and thermal ratings. Direct substitution is supported without circuit modification.

Q: What is the difference between MJS 2 and MJS 2-R?

A: The primary differences are product status and compliance certifications. The MJS 2 is obsolete; the MJS 2-R is active production. The MJS 2-R includes ROHS3 compliance and cULus certification (combined UL/CSA approval). DC cold resistance differs slightly (0.064 Ohms vs. 0.094 Ohms) but does not impact circuit protection function.

Q: Are there any compatibility concerns with the 2AG package format?

A: No. Both parts use identical 2AG package specifications (5mm x 15mm axial, 0.217" diameter). Physical fit and electrical connection are identical. Through-hole mounting configuration is the same for both parts.

Q: Does the lower DC cold resistance of MJS 2-R affect circuit performance?

A: No. DC cold resistance variance between these parts is within normal manufacturing tolerances and does not affect fuse operation, trip characteristics, or circuit protection performance.

Q: Which certifications does MJS 2-R carry?

A: MJS 2-R carries CE, CSA, cULus, and PSE certifications. The cULus marking represents combined UL and CSA approval, providing broader regulatory recognition than separate certifications.