SPJ-5M225 Equivalent & Substitute Parts

Part Overview

The SPJ-5M225 is a 225A radial bend fuse manufactured by Eaton - Bussmann Electrical Division, part of the Semitron™ SPJ series. This through-hole mounted fuse is rated for 1kV operation and features a compact cylindrical design (0.181" Dia x 0.760" L). The product is currently obsolete, making identification of functionally equivalent alternatives essential for system maintenance, repair, and component sourcing in legacy electrical installations.

Substiute Parts

SPJ-5M225

Eaton - Bussmann Electrical DivisionIn Stock: 710SPJ-5M225 Datasheet

Current PartRFQ

170M4490

Eaton - Bussmann Electrical DivisionIn Stock: 1229170M4490 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The 170M4490 is identified as a substitute for the SPJ-5M225 based on the following electrical and mechanical compatibility criteria:

Electrical Parameters:

• Both components are manufactured by Eaton - Bussmann Electrical Division, ensuring design and quality consistency
• Current rating differential (225A vs. 250A) falls within acceptable substitution parameters for high-current fuse applications
• Voltage rating upgrade (1kV to 1.3kVAC) provides enhanced electrical protection margin
• Both components carry EAR99 ECCN classification

Mechanical & Compliance Parameters:

• Both components are REACH Unaffected, ensuring regulatory compliance
• Active product status of 170M4490 ensures ongoing availability and supply chain reliability
• CSA and UR approvals on the substitute part confirm third-party validation for industrial and electrical applications

Substitution Limitations: The 170M4490 requires a dedicated holder (square blade configuration), whereas the SPJ-5M225 is a through-hole radial bend design. This represents a mechanical interface change that requires circuit board or mounting assembly modification.

Parameter Comparison

Engineering Selection Recommendations

Selection of the 170M4490 as a substitute for the SPJ-5M225 is supported by:

• Manufacturer Consistency: Both components originate from Eaton - Bussmann Electrical Division, ensuring design philosophy and quality standards alignment
• Regulatory Compliance: The 170M4490 holds active CSA and UR certifications, providing documented third-party validation for industrial electrical applications
• Supply Chain Availability: Active product status ensures reliable sourcing, whereas the SPJ-5M225 is obsolete
• Electrical Margin: The 250A current rating and 1.3kVAC voltage rating of the 170M4490 provide operational headroom above the original 225A / 1kV specification

Critical Implementation Consideration: The transition from through-hole radial bend mounting to square blade holder-based mounting requires mechanical redesign of the circuit board or mounting assembly. This is not a direct drop-in replacement and necessitates hardware modification.

Frequently Asked Questions (FAQ)

Q: Can the 170M4490 be used as a direct replacement without circuit board modification?

A: No. The SPJ-5M225 is a through-hole radial bend component, while the 170M4490 requires a dedicated square blade holder. Direct substitution requires mounting assembly redesign.

Q: What is the significance of the current rating increase from 225A to 250A?

A: The 250A rating of the 170M4490 provides a 25A margin above the original specification. This is acceptable in fuse substitution where the higher rating does not compromise circuit protection, provided the circuit design accommodates this tolerance.

Q: Are there compliance differences between the two components?

A: The 170M4490 carries CSA and UR approvals, whereas approval agency information is not provided for the SPJ-5M225. The 170M4490's active certifications support its use in regulated industrial and electrical applications.

Q: Why is the SPJ-5M225 listed as obsolete?

A: Obsolescence indicates the manufacturer has discontinued production. The 170M4490, as an active product, represents the current generation equivalent within the Eaton - Bussmann product portfolio.

Q: What is the voltage rating significance of 1kV vs. 1.3kVAC?

A: The 1.3kVAC rating of the 170M4490 exceeds the original 1kV specification, providing enhanced dielectric protection. This upgrade is compatible with systems designed for 1kV operation.