SPJ-5K225 Equivalent & Substitute Parts Reference

Part Overview

The SPJ-5K225 is a 225A 1kV radial bend through-hole fuse manufactured by Eaton - Bussmann Electrical Division, part of the Semitron™ SPJ series. This component is classified as obsolete, indicating that direct replacement from the original manufacturer is no longer available. Finding equivalent or substitute parts is necessary to maintain system functionality and ensure continued availability for repair, maintenance, or new installations requiring compatible fuse protection.

Substiute Parts

SPJ-5K225

Eaton - Bussmann Electrical DivisionIn Stock: 900SPJ-5K225 Datasheet

Current PartRFQ

170M4490

Eaton - Bussmann Electrical DivisionIn Stock: 1229170M4490 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SPJ-5K225 is constrained by the following critical parameters:

• Current Rating: 225A nominal
• Voltage Rating: 1kV minimum
• Manufacturer: Eaton - Bussmann Electrical Division (same manufacturer ensures design compatibility)
• Mounting Type & Package: Through-hole radial bend cylinder form factor

The identified substitute part 170M4490 is from the same manufacturer but differs in several key aspects: it is rated for 250A at 1.3kVAC, requires a holder for mounting (not through-hole), and uses a rectangular blade package. These differences indicate that 170M4490 operates in a different electrical and mechanical context and cannot be considered a direct functional equivalent for applications requiring the SPJ-5K225's specific form factor and mounting characteristics.

Parameter Comparison

Engineering Selection Recommendations

The SPJ-5K225 is obsolete and no longer manufactured. The 170M4490 is an active product from the same manufacturer and represents current Eaton - Bussmann technology. However, substitution requires careful evaluation:

• Electrical Compatibility: The 170M4490 provides higher current (250A) and voltage (1.3kVAC) ratings, which may be acceptable in applications with design margin, but this must be verified against circuit requirements.
• Mechanical Incompatibility: The 170M4490 requires a separate holder and uses a rectangular blade package, fundamentally different from the through-hole radial bend form factor of the SPJ-5K225. Direct mechanical substitution in existing through-hole PCB or panel mount designs is not possible without redesign.
• Compliance: Both parts carry ECCN EAR99 classification and are subject to the same export control framework.

Substitution of the SPJ-5K225 with the 170M4490 requires circuit redesign and mechanical accommodation for the holder-based mounting system.

Frequently Asked Questions (FAQ)

Q: Can the 170M4490 be used as a direct replacement for the SPJ-5K225?

A: No. While both are Eaton - Bussmann fuses, they differ in mounting type (through-hole vs. holder-based), package form factor (radial cylinder vs. rectangular blade), and physical dimensions. Direct substitution in existing designs is not possible without mechanical and electrical redesign.

Q: What are the key differences between these two fuses?

A: The SPJ-5K225 is a 225A 1kV through-hole radial fuse with a compact cylindrical form factor. The 170M4490 is a 250A 1.3kVAC rectangular blade fuse requiring a separate holder. They serve different circuit architectures and cannot be interchanged without system modification.

Q: Is the 170M4490 electrically compatible with SPJ-5K225 applications?

A: The 170M4490 has higher current and voltage ratings (250A, 1.3kVAC vs. 225A, 1kV). Electrical compatibility depends on the specific circuit design and whether the higher ratings are acceptable. This must be evaluated on a case-by-case basis.

Q: Why is the SPJ-5K225 obsolete?

A: Product obsolescence is determined by the manufacturer based on market demand and product lifecycle decisions. The SPJ-5K225 has been discontinued, and Eaton - Bussmann no longer manufactures this specific model.

Q: What should I do if I need to replace an SPJ-5K225 in an existing system?

A: Evaluate whether the circuit can accommodate the 170M4490's higher ratings and holder-based mounting. If not, consult with Eaton - Bussmann technical support or seek alternative fuse manufacturers offering compatible through-hole radial designs at 225A 1kV specifications.