LPJ-400SPI Equivalent & Substitute Parts

Part Overview

The LPJ-400SPI is a 400A fuse cartridge manufactured by Eaton - Bussmann Electrical Division, rated for 600 VAC and 300 VDC operation. This slow-blow Class J cartridge fuse features bolt mount installation with an alarm indicator and is designed for industrial and electrical applications requiring high breaking capacity (300kA AC, 100kA DC). The part is currently active in production with 907 units in stock. Substitute parts are identified when equivalent electrical ratings and mechanical compatibility allow direct functional replacement in the application circuit.

Substiute Parts

LPJ-400SPI

Eaton - Bussmann Electrical DivisionIn Stock: 1004LPJ-400SPI Datasheet

Current PartRFQ

0JTD400.X

LittelfuseIn Stock: 7130JTD400.X Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The LPJ-400SPI has one identified substitute: the 0JTD400.X (Littelfuse POWR-GARD®/POWR-PRO® JTD series). Substitution eligibility is determined by the following parameters:

• Current Rating: Both parts rated 400A
• Voltage Rating - AC: Both rated 600 VAC
• Fuse Type: Both are Class J cartridge fuses
• Response Time: Both are slow-blow
• Physical Dimensions: Both measure 2.000" Dia x 3.374–3.380" L (within tolerance)
• Approval Certifications: Both hold CE, CSA, and UL approvals

The 0JTD400.X differs in DC voltage rating (500 VDC vs. 300 VDC) and mounting configuration (requires holder vs. bolt mount). These differences establish the substitution boundary and must be evaluated against application requirements.

Parameter Comparison

Engineering Selection Recommendations

Both the LPJ-400SPI and 0JTD400.X are active production parts with full CE, CSA, and UL certifications, confirming compliance with international electrical safety standards. Selection between these parts depends on application-specific requirements:

The LPJ-400SPI is specified when bolt mount installation is required and DC voltage operation does not exceed 300 VDC. The higher breaking capacity (300kA AC, 100kA DC) provides margin in high-fault-current environments.

The 0JTD400.X is applicable when holder-based mounting is acceptable and DC voltage operation extends to 500 VDC. The lower breaking capacity (200kA AC, 20kA DC) is suitable for applications with reduced fault current levels.

Both parts maintain identical 400A AC current rating, 600 VAC AC voltage rating, Class J classification, and slow-blow response characteristics. Physical dimensions are equivalent within manufacturing tolerance.

Frequently Asked Questions (FAQ)

Q: Can the 0JTD400.X replace the LPJ-400SPI in all applications?

A: No. The 0JTD400.X requires a separate holder for installation, whereas the LPJ-400SPI uses bolt mount. Additionally, the 0JTD400.X has lower breaking capacity (200kA AC vs. 300kA AC). Substitution is valid only when the application circuit accommodates holder-based mounting and fault current does not exceed the 0JTD400.X breaking capacity rating.

Q: What is the significance of the DC voltage rating difference?

A: The LPJ-400SPI is rated 300 VDC maximum, while the 0JTD400.X is rated 500 VDC maximum. If the application operates at DC voltages above 300 VDC, the LPJ-400SPI is not suitable. Conversely, if DC operation is not required or remains below 300 VDC, both parts are electrically equivalent for that parameter.

Q: Are both parts RoHS compliant?

A: Yes. The LPJ-400SPI is RoHS Compliant, and the 0JTD400.X is ROHS3 Compliant. Both meet current environmental compliance requirements.

Q: What does "Class J" mean for these fuses?

A: Class J is a standardized fuse classification indicating physical dimensions, electrical characteristics, and performance parameters. Both the LPJ-400SPI and 0JTD400.X conform to Class J specifications, ensuring interchangeability within the constraint of their respective mounting and breaking capacity ratings.

Q: Why is breaking capacity important?

A: Breaking capacity specifies the maximum fault current the fuse can safely interrupt without rupturing or creating a hazard. The LPJ-400SPI (300kA AC, 100kA DC) has higher breaking capacity than the 0JTD400.X (200kA AC, 20kA DC). In circuits with high fault current potential, the LPJ-400SPI provides greater safety margin.