Available to order
Request a QuoteNeed multiple units or help confirming a model? Contact our team.
Available payment methods
Shop with complete confidence. Whatever the reason, enjoy hassle-free returns and exchanges within 30 days. We cover all shipping costs for both returns and exchanges—no extra shipping fees, no worries.
Technical specifications, features, applications and purchasing information.
| Brand | Littelfuse |
| Model Number | KLKR-4 |
| Product Category | Class CC Fast-Acting Fuse |
| Product Series | POWR-GARD KLKR |
| Current Rating | 4 A (4000 mA) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Fuse Class | UL Class CC |
The Littelfuse KLKR-4 features a 4 ampere current rating, equivalent to 4000 milliamperes. It is designed for appropriately specified industrial electrical equipment, control circuits and branch circuit applications requiring Class CC fast-acting overcurrent protection.
The KLKR series provides fast-acting protection for electrical circuits requiring a rapid response to overload conditions. Unlike the KLDR time-delay series, KLKR fuses are designed for fast overload response. Normal startup currents, temporary load changes and inrush conditions must be evaluated when selecting a fuse.
The fuse is rated for compatible AC circuits up to 600 VAC and DC circuits up to 300 VDC. Separate AC and DC voltage ratings support protective-device selection according to circuit operating voltage, installation requirements and prospective short-circuit current.
The KLKR series provides an AC interrupting rating of 200 kA RMS symmetrical and a separate DC interrupting rating of 20 kA. Littelfuse identifies the DC rating as manufacturer self-certified. Available prospective fault current must remain within the applicable interrupting capacity.
The current-limiting design helps reduce heating and magnetic effects associated with short-circuit events. Rejection-style construction helps prevent installation of fuses with insufficient voltage or interrupting ratings when used with compatible Class CC rejection-type fuse holders.
Features a melamine body, nickel-plated bronze end caps and a nominal 10.3 x 38.1 mm cartridge format. Littelfuse specifies a series weight of 15.42 g for the 1.5 A through 30 A ratings. Compatible accessories include appropriately rated L60030C and LPSC/LFPSC Touch-Safe fuse holder series.
We support online purchase of the Littelfuse KLKR-4 Class CC Fast-Acting Fuse. If you need to make bulk purchases and inquire about other products, please contact our team to inform us of your purchase requirements. We will provide you with information such as quantity quotations, delivery dates, and transportation methods. Please verify the required model, current rating and purchase quantity before ordering.
What is the Littelfuse KLKR-4?
It is a 4 A Class CC fast-acting, current-limiting cartridge fuse from the Littelfuse POWR-GARD KLKR series. It is intended for general-purpose branch circuit protection and applications requiring fast overload response.
What is the manufacturer catalog number?
The manufacturer catalog number is KLKR004. The product marking is KLKR 4A, and Littelfuse lists KLKR004.T as the manufacturer ordering number for a 10-piece pack.
What is the current rating of KLKR-4?
The rated current is 4 amperes, equivalent to 4000 milliamperes.
What are the AC and DC voltage ratings?
Littelfuse specifies 600 VAC and 300 VDC for the KLKR series. The circuit operating voltage must remain within the applicable AC or DC rating.
What are the interrupting ratings?
The AC interrupting rating is 200,000 amperes RMS symmetrical, and the DC interrupting rating is 20,000 amperes. Littelfuse identifies the DC interrupting rating as manufacturer self-certified.
Is KLKR-4 fast-acting or time-delay?
KLKR-4 is a fast-acting fuse. It belongs to the KLKR series, which provides fast overload protection. The KLDR series has time-delay characteristics and should not be considered electrically identical.
Can KLKR-4 replace a KLDR-4 fuse?
Not automatically. Although both are Class CC fuses with a nominal 4 A current rating, KLKR is fast-acting while KLDR is time-delay. Replacement suitability depends on circuit design, expected inrush current and the required overcurrent response.
Is KLKR-4 suitable for industrial control panels?
The KLKR series is intended for general-purpose branch circuit protection and is used in OEM equipment and control panels. The 4 A fuse must be selected according to the equipment specifications, circuit voltage, expected load and protective-device coordination requirements.
Does Littelfuse publish a specific I²t value for KLKR-4?
The Littelfuse KLKR datasheet revised February 25, 2025 does not provide an individual numerical total clearing I²t value for KLKR004.T in its ordering table. Values for other current ratings should not be substituted for the 4 A model.
What are the dimensions and construction materials?
The nominal cartridge dimensions are 10.3 mm in diameter and 38.1 mm in length. The KLKR series features a melamine body and nickel-plated bronze end caps. Littelfuse specifies a series weight of 15.42 g for ratings from 1.5 A through 30 A.
Which fuse holders are recommended?
Littelfuse lists the L60030C and LPSC/LFPSC Touch-Safe holder series as accessories. Confirm Class CC compatibility and the required voltage and electrical ratings before installation.
Is KLKR-4 UL listed and RoHS compliant?
The KLKR series is UL Listed under file E81895 and CSA Certified under file LR29862. Littelfuse also identifies RoHS compliance and references CE Declaration of Conformity KLKR_210128_1. The DC interrupting rating is separately manufacturer self-certified.
What should be verified before ordering KLKR-4?
Confirm the KLKR-4 or KLKR004 designation, 4 A current rating, applicable 600 VAC or 300 VDC circuit requirement, fast-acting characteristic, interrupting capacity, Class CC fuse holder compatibility and desired purchase quantity. Littelfuse lists KLKR004.T for a manufacturer 10-piece pack; this does not establish the quantity supplied by an individual store listing.
Send us your part number and technical requirements.
Explore more industrial components from our catalog.
Available in stock (2000)
| Brand | Littelfuse |
| Model Number | KLKR-4 |
| Product Category | Class CC Fast-Acting Fuse |
| Product Series | POWR-GARD KLKR |
| Current Rating | 4 A (4000 mA) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Fuse Class | UL Class CC |
The Littelfuse KLKR-4 features a 4 ampere current rating, equivalent to 4000 milliamperes. It is designed for appropriately specified industrial electrical equipment, control circuits and branch circuit applications requiring Class CC fast-acting overcurrent protection.
The KLKR series provides fast-acting protection for electrical circuits requiring a rapid response to overload conditions. Unlike the KLDR time-delay series, KLKR fuses are designed for fast overload response. Normal startup currents, temporary load changes and inrush conditions must be evaluated when selecting a fuse.
The fuse is rated for compatible AC circuits up to 600 VAC and DC circuits up to 300 VDC. Separate AC and DC voltage ratings support protective-device selection according to circuit operating voltage, installation requirements and prospective short-circuit current.
The KLKR series provides an AC interrupting rating of 200 kA RMS symmetrical and a separate DC interrupting rating of 20 kA. Littelfuse identifies the DC rating as manufacturer self-certified. Available prospective fault current must remain within the applicable interrupting capacity.
The current-limiting design helps reduce heating and magnetic effects associated with short-circuit events. Rejection-style construction helps prevent installation of fuses with insufficient voltage or interrupting ratings when used with compatible Class CC rejection-type fuse holders.
Features a melamine body, nickel-plated bronze end caps and a nominal 10.3 x 38.1 mm cartridge format. Littelfuse specifies a series weight of 15.42 g for the 1.5 A through 30 A ratings. Compatible accessories include appropriately rated L60030C and LPSC/LFPSC Touch-Safe fuse holder series.
We support online purchase of the Littelfuse KLKR-4 Class CC Fast-Acting Fuse. If you need to make bulk purchases and inquire about other products, please contact our team to inform us of your purchase requirements. We will provide you with information such as quantity quotations, delivery dates, and transportation methods. Please verify the required model, current rating and purchase quantity before ordering.
What is the Littelfuse KLKR-4?
It is a 4 A Class CC fast-acting, current-limiting cartridge fuse from the Littelfuse POWR-GARD KLKR series. It is intended for general-purpose branch circuit protection and applications requiring fast overload response.
What is the manufacturer catalog number?
The manufacturer catalog number is KLKR004. The product marking is KLKR 4A, and Littelfuse lists KLKR004.T as the manufacturer ordering number for a 10-piece pack.
What is the current rating of KLKR-4?
The rated current is 4 amperes, equivalent to 4000 milliamperes.
What are the AC and DC voltage ratings?
Littelfuse specifies 600 VAC and 300 VDC for the KLKR series. The circuit operating voltage must remain within the applicable AC or DC rating.
What are the interrupting ratings?
The AC interrupting rating is 200,000 amperes RMS symmetrical, and the DC interrupting rating is 20,000 amperes. Littelfuse identifies the DC interrupting rating as manufacturer self-certified.
Is KLKR-4 fast-acting or time-delay?
KLKR-4 is a fast-acting fuse. It belongs to the KLKR series, which provides fast overload protection. The KLDR series has time-delay characteristics and should not be considered electrically identical.
Can KLKR-4 replace a KLDR-4 fuse?
Not automatically. Although both are Class CC fuses with a nominal 4 A current rating, KLKR is fast-acting while KLDR is time-delay. Replacement suitability depends on circuit design, expected inrush current and the required overcurrent response.
Is KLKR-4 suitable for industrial control panels?
The KLKR series is intended for general-purpose branch circuit protection and is used in OEM equipment and control panels. The 4 A fuse must be selected according to the equipment specifications, circuit voltage, expected load and protective-device coordination requirements.
Does Littelfuse publish a specific I²t value for KLKR-4?
The Littelfuse KLKR datasheet revised February 25, 2025 does not provide an individual numerical total clearing I²t value for KLKR004.T in its ordering table. Values for other current ratings should not be substituted for the 4 A model.
What are the dimensions and construction materials?
The nominal cartridge dimensions are 10.3 mm in diameter and 38.1 mm in length. The KLKR series features a melamine body and nickel-plated bronze end caps. Littelfuse specifies a series weight of 15.42 g for ratings from 1.5 A through 30 A.
Which fuse holders are recommended?
Littelfuse lists the L60030C and LPSC/LFPSC Touch-Safe holder series as accessories. Confirm Class CC compatibility and the required voltage and electrical ratings before installation.
Is KLKR-4 UL listed and RoHS compliant?
The KLKR series is UL Listed under file E81895 and CSA Certified under file LR29862. Littelfuse also identifies RoHS compliance and references CE Declaration of Conformity KLKR_210128_1. The DC interrupting rating is separately manufacturer self-certified.
What should be verified before ordering KLKR-4?
Confirm the KLKR-4 or KLKR004 designation, 4 A current rating, applicable 600 VAC or 300 VDC circuit requirement, fast-acting characteristic, interrupting capacity, Class CC fuse holder compatibility and desired purchase quantity. Littelfuse lists KLKR004.T for a manufacturer 10-piece pack; this does not establish the quantity supplied by an individual store listing.
