KTQ-4 Equivalent & Substitute Parts

Part Overview

The KTQ-4 is a 4A 600VAC ceramic cartridge fuse manufactured by Eaton - Bussmann Electrical Division. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for system maintenance and component replacement in existing installations. The KTQ-4 requires a dedicated fuse holder for operation and is designed for fast-blow response characteristics in electrical and industrial applications.

Substiute Parts

KTQ-4

Eaton - Bussmann Electrical DivisionIn Stock: 809KTQ-4 Datasheet

Current PartRFQ

BBS-4

Eaton - Bussmann Electrical DivisionIn Stock: 779BBS-4 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KTQ-4 is determined by strict equivalence across the following critical parameters:

• Current Rating: 4 A (exact match required)
• Voltage Rating: 600 VAC (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity: 10 kA @ Rated Voltage (exact match required)
• Fuse Type: Cartridge configuration (exact match required)
• Mounting Type: Requires Holder (exact match required)

The BBS-4 meets all substitution criteria. Both components share identical electrical ratings, breaking capacity, response characteristics, and holder-based mounting requirements. Physical dimensions show negligible variation (0.406" vs 0.410" diameter; 1.378" vs 1.380" length), which remains within acceptable tolerance for standard cartridge fuse holders.

Parameter Comparison

Engineering Selection Recommendations

The BBS-4 is the direct equivalent substitute for the obsolete KTQ-4. Both components are manufactured by Eaton - Bussmann Electrical Division and satisfy identical electrical and mechanical specifications. The BBS-4 carries active product status, ensuring ongoing availability and supply chain continuity.

The BBS-4 holds expanded approval certifications (CE, CSA, UL) compared to the KTQ-4 (UL only), providing additional compliance coverage for international and North American applications. Both components maintain identical breaking capacity (10 kA), current rating (4 A), voltage rating (600 VAC), and fast-blow response characteristics.

Physical dimensions between the two cartridges show negligible variation within standard manufacturing tolerances, confirming mechanical compatibility with existing KTQ-4 fuse holders.

Frequently Asked Questions (FAQ)

Q: Can the BBS-4 be used as a direct replacement for the KTQ-4?

A: Yes. The BBS-4 meets all electrical and mechanical specifications of the KTQ-4, including current rating (4 A), voltage rating (600 VAC), breaking capacity (10 kA), response time (fast blow), and holder-based mounting requirements. Physical dimensions are within acceptable tolerance.

Q: What is the primary reason for substitution?

A: The KTQ-4 is classified as obsolete. The BBS-4 is an active product from the same manufacturer with identical electrical performance, ensuring continued availability and supply reliability.

Q: Are there any compliance differences between the KTQ-4 and BBS-4?

A: The BBS-4 carries additional certifications (CE, CSA) beyond the UL approval held by the KTQ-4. This expanded certification scope does not affect compatibility but provides broader regulatory coverage for international applications.

Q: Will the BBS-4 fit existing KTQ-4 fuse holders?

A: Yes. Both cartridges use non-standard cartridge packaging with dimensions within acceptable tolerance (diameter: 0.406" vs 0.410"; length: 1.378" vs 1.380"). Standard fuse holders accommodate this dimensional variation.

Q: Are the electrical characteristics identical?

A: Yes. Current rating, voltage rating, breaking capacity, and response time are identical between the KTQ-4 and BBS-4.