LA70Q704 Fuse Cartridge Equivalent & Substitute Parts

Part Overview

The LA70Q704 is a 70A cartridge fuse rated for 700 VAC / 650 VDC operation, designed for bolt mount applications in electrical and industrial systems. This part is classified as obsolete, making identification of suitable substitutes necessary for ongoing maintenance and system support. The LA70Q704 features a cylindrical design with blade terminal (bolt) mounting and is ROHS3 compliant with a breaking capacity of 100kA at rated voltage.

Substiute Parts

LA70Q704

Littelfuse Inc.In Stock: 1039LA70Q704 Datasheet

Current PartRFQ

L70QS070.V

Littelfuse Inc.In Stock: 903L70QS070.V Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LA70Q704 is based on the following critical parameters:

• Current Rating: Must be 70A to maintain circuit protection design
• Voltage Rating - AC: Must be 700 VAC or higher to ensure adequate voltage margin
• Voltage Rating - DC: Must be 650 VDC or higher for DC circuit compatibility
• Mounting Type: Must be Bolt Mount to ensure mechanical compatibility with existing installations
• Fuse Type: Must be Cartridge type with Cylindrical, Blade Terminal (Bolt) configuration
• Breaking Capacity: Must meet or exceed 100kA at rated voltage for fault protection integrity

The L70QS070.V meets all substitution criteria as an active product from the same manufacturer with identical current rating, matching AC voltage rating, superior DC voltage rating (700 VDC vs. 650 VDC), and enhanced breaking capacity (200kA AC / 50kA DC).

Parameter Comparison

Engineering Selection Recommendations

The L70QS070.V is the qualified substitute for the LA70Q704 based on the following factors:

• Product Status: The L70QS070.V is an active product with current manufacturing support, whereas the LA70Q704 is obsolete and subject to availability constraints
• Electrical Compatibility: Both parts maintain identical 70A current rating and 700 VAC AC voltage rating. The L70QS070.V provides enhanced DC voltage rating (700 VDC vs. 650 VDC), ensuring superior performance margin in DC applications
• Mechanical Compatibility: Both parts feature identical bolt mount cartridge configuration with cylindrical blade terminal design, ensuring direct mechanical fit in existing installations
• Regulatory Compliance: The L70QS070.V carries expanded approval certifications (CE, cURus, UR) compared to the LA70Q704 (UR only), providing broader regulatory acceptance
• Performance Enhancement: The L70QS070.V offers significantly higher breaking capacity (200kA AC / 50kA DC vs. 100kA), providing improved fault protection capability

Frequently Asked Questions (FAQ)

Q: Can the L70QS070.V directly replace the LA70Q704 in existing installations?

A: Yes. Both parts share identical current rating (70A), AC voltage rating (700 VAC), mounting type (Bolt Mount), and physical package configuration (Cylindrical, Blade Terminal). The L70QS070.V provides enhanced DC voltage rating and breaking capacity, making it electrically and mechanically compatible.

Q: What is the difference in DC voltage rating between these parts?

A: The LA70Q704 is rated for 650 VDC, while the L70QS070.V is rated for 700 VDC. This 50 VDC increase in the substitute part provides additional voltage margin for DC circuit applications.

Q: Are there physical size differences between the LA70Q704 and L70QS070.V?

A: Yes. The LA70Q704 measures 1.220" Dia x 2.874" L (31.00mm x 73.00mm), while the L70QS070.V measures 1.000" Dia x 4.375" L (25.40mm x 111.13mm). Physical dimensions differ, but both maintain bolt mount cartridge configuration suitable for standard fuse holders designed for this mounting type.

Q: What certifications does the L70QS070.V carry?

A: The L70QS070.V carries CE, cURus, and UR approvals, providing broader regulatory acceptance compared to the LA70Q704, which carries UR approval only.

Q: Why is the breaking capacity higher on the L70QS070.V?

A: The L70QS070.V is specified with 200kA AC and 50kA DC breaking capacity, compared to 100kA for the LA70Q704. This enhanced breaking capacity reflects improved fault protection design in the active product line.