KTK-R-4 Equivalent & Substitute Parts

Part Overview

The KTK-R-4 is a 4A 600VAC fast-blow cartridge fuse manufactured by Eaton - Bussmann Electrical Division, part of the Limitron™ KTK-R series. This fuse is designed for electrical and industrial applications requiring cartridge-style protection in a 5AG (10mm x 38mm midget) package format. The part is currently active in production with 993 units in stock. Substitute parts are identified to provide alternative sourcing options when the primary part is unavailable or when system requirements permit equivalent protection devices.

Substiute Parts

KTK-R-4

Eaton - Bussmann Electrical DivisionIn Stock: 1032KTK-R-4 Datasheet

Current PartRFQ

0KLK004.T

Littelfuse Inc.In Stock: 8220KLK004.T Datasheet

DirectRFQ

KLKR004.T

Littelfuse Inc.In Stock: 1294KLKR004.T Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the KTK-R-4 are qualified based on the following critical parameters that must align with the main part:

• Current Rating: 4A (exact match required)
• Voltage Rating - AC: 600 VAC (exact match required)
• Fuse Type: Cartridge (exact match required)
• Response Time: Fast Blow (exact match required)
• Package / Case: 5AG, 10mm x 38mm (Midget) (exact match required)
• Size / Dimension: 0.406" Dia x 1.500" L (exact match required)
• Mounting Type: Requires Holder (exact match required)

The identified substitutes meet all critical electrical and mechanical parameters. Variations in DC voltage ratings, breaking capacity, and packaging format (bulk vs. box) do not affect AC circuit compatibility when the AC parameters are identical.

Parameter Comparison

Engineering Selection Recommendations

All three parts are active products with current manufacturing status and full regulatory compliance across CE, CSA, and UL certifications. Selection between the main part and substitutes should be based on:

• Availability: KLKR004.T offers the highest inventory (1226 units) compared to KTK-R-4 (993 units) and 0KLK004.T (793 units).
• Breaking Capacity: KTK-R-4 and KLKR004.T both provide 200kA AC breaking capacity, while 0KLK004.T provides 100kA AC. For applications requiring maximum fault current protection, KTK-R-4 or KLKR004.T are preferred.
• DC Voltage Capability: 0KLK004.T supports 500 VDC and KLKR004.T supports 300 VDC. The main part does not specify DC rating. For AC-only circuits, this difference is not relevant.
• Packaging: KTK-R-4 and 0KLK004.T are supplied in bulk packaging; KLKR004.T is supplied in box packaging. Procurement requirements may influence selection.

Frequently Asked Questions (FAQ)

Q: Can 0KLK004.T be used as a direct replacement for KTK-R-4?

A: 0KLK004.T meets all critical AC electrical parameters (4A, 600 VAC, fast-blow, cartridge type) and physical dimensions (5AG, 10mm x 38mm). However, it provides 100kA AC breaking capacity compared to 200kA for the main part. Use 0KLK004.T only in circuits where 100kA breaking capacity is sufficient.

Q: Can KLKR004.T be used as a direct replacement for KTK-R-4?

A: Yes. KLKR004.T matches all critical parameters including current rating (4A), AC voltage (600 VAC), response time (fast-blow), physical dimensions (5AG, 10mm x 38mm), and breaking capacity (200kA AC). The only difference is packaging format (box vs. bulk).

Q: What is the significance of the 5AG package designation?

A: 5AG is a standardized cartridge fuse package size (10mm x 38mm midget format). All three parts use this identical package, ensuring mechanical compatibility with standard 5AG fuse holders.

Q: Are there any compatibility concerns with DC circuits?

A: The main part (KTK-R-4) does not specify a DC voltage rating. The substitutes provide DC ratings (500 VDC for 0KLK004.T and 300 VDC for KLKR004.T). For DC applications, use only the substitute parts with appropriate DC voltage ratings.

Q: What certifications apply to all three parts?

A: All three parts hold CE, CSA, and UL certifications. 0KLK004.T additionally holds QPL certification. All are ROHS3 compliant.