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Technical specifications, features, applications and purchasing information.
| Brand | Littelfuse |
| Model Number | KLKR-3 |
| Product Category | Class CC Fast-Acting Fuse |
| Product Series | POWR-GARD KLKR |
| Current Rating | 3 A (3000 mA) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Fuse Class | UL Class CC |
| Operating Characteristic | Fast-Acting (Fast-Blow) |
| Fuse Type | Current-Limiting Cartridge Fuse |
| AC Interrupting Rating | 200 kA RMS Symmetrical (200,000 A) |
| DC Interrupting Rating | 20 kA (20,000 A, Manufacturer Self-Certified) |
| Primary Protection Function | Fast Overload Protection |
| Intended Circuit Protection | General-Purpose Branch Circuit Protection |
| Fuse Format | Class CC Rejection-Style Cartridge |
| Nominal Dimensions | 10.3 x 38.1 mm (0.41 x 1.50 in) |
The Littelfuse KLKR-3 provides a 3 ampere current rating, equivalent to 3000 milliamperes, for appropriately specified industrial electrical equipment, control circuits and branch circuit applications. Its rating supports installations requiring Class CC fast-acting overcurrent protection.
The KLKR series is designed for circuits and equipment requiring a fast response to overload conditions. Unlike the KLDR time-delay series, KLKR fuses have fast-acting characteristics. Normal startup currents, transient loads and inrush conditions must be evaluated during protective-device selection.
Rated for compatible AC circuits up to 600 VAC and DC circuits up to 300 VDC. The separate voltage ratings support fuse selection according to operating voltage, circuit design and the available 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 its DC interrupting rating as manufacturer self-certified. The available fault current must remain within the applicable interrupting rating.
Current-limiting construction helps reduce the heating and magnetic effects associated with short-circuit events. Rejection-style construction helps prevent the 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. Recommended accessories include compatible L60030C and LPSC/LFPSC Touch-Safe fuse holder families.
We support online purchase of the Littelfuse KLKR-3 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-3?
It is a 3 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 a fast overload response.
What is the manufacturer catalog number?
The manufacturer catalog number is KLKR003. Littelfuse specifies the product marking KLKR 3A and lists KLKR003.T as the manufacturer ordering number for a 10-piece pack.
What is the current rating of KLKR-3?
The rated current is 3 amperes, equivalent to 3000 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 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-3 a fast-acting or time-delay fuse?
KLKR-3 is a fast-acting fuse. It belongs to the KLKR series, which is designed for fast overload protection. The KLDR series has time-delay characteristics and should not be considered electrically identical.
Can KLKR-3 replace a KLDR-3 fuse?
Not automatically. Both are Class CC fuses with a nominal 3 A current rating, but they have different overload response characteristics. Replacement suitability depends on the protected circuit, expected inrush current and applicable protection requirements.
Is KLKR-3 suitable for industrial control transformer circuits?
Littelfuse identifies control transformer circuits among the KLKR series applications where fast overload response is required. The transformer's magnetizing inrush current, circuit design and protective-device coordination must be evaluated before selection.
Does Littelfuse specify an individual total clearing I²t value for KLKR-3?
The KLKR datasheet revised February 25, 2025 provides numerical total clearing I²t values for selected reference ratings but does not list an individual numerical value for KLKR003.T. Values for the 1 A, 6 A or other KLKR ratings must not be substituted for the 3 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 uses a melamine body and nickel-plated bronze end caps. Littelfuse specifies a series weight of 15.42 g for the 1.5 A through 30 A ratings.
Which fuse holders are recommended?
Littelfuse lists the L60030C and LPSC/LFPSC Touch-Safe fuse holder series as accessories. Confirm the holder's Class CC compatibility, voltage rating and electrical capacity before installation.
Is KLKR-3 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 manufacturer self-certified.
What should be verified before ordering KLKR-3?
Confirm the KLKR-3 or KLKR003 designation, 3 A current rating, applicable 600 VAC or 300 VDC circuit requirement, fast-acting characteristics, interrupting capacity, Class CC fuse-holder compatibility and desired purchase quantity. Littelfuse lists KLKR003.T as a manufacturer 10-piece pack ordering number; this does not establish the quantity supplied by an individual store listing.
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| Brand | Littelfuse |
| Model Number | KLKR-3 |
| Product Category | Class CC Fast-Acting Fuse |
| Product Series | POWR-GARD KLKR |
| Current Rating | 3 A (3000 mA) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Fuse Class | UL Class CC |
| Operating Characteristic | Fast-Acting (Fast-Blow) |
| Fuse Type | Current-Limiting Cartridge Fuse |
| AC Interrupting Rating | 200 kA RMS Symmetrical (200,000 A) |
| DC Interrupting Rating | 20 kA (20,000 A, Manufacturer Self-Certified) |
| Primary Protection Function | Fast Overload Protection |
| Intended Circuit Protection | General-Purpose Branch Circuit Protection |
| Fuse Format | Class CC Rejection-Style Cartridge |
| Nominal Dimensions | 10.3 x 38.1 mm (0.41 x 1.50 in) |
The Littelfuse KLKR-3 provides a 3 ampere current rating, equivalent to 3000 milliamperes, for appropriately specified industrial electrical equipment, control circuits and branch circuit applications. Its rating supports installations requiring Class CC fast-acting overcurrent protection.
The KLKR series is designed for circuits and equipment requiring a fast response to overload conditions. Unlike the KLDR time-delay series, KLKR fuses have fast-acting characteristics. Normal startup currents, transient loads and inrush conditions must be evaluated during protective-device selection.
Rated for compatible AC circuits up to 600 VAC and DC circuits up to 300 VDC. The separate voltage ratings support fuse selection according to operating voltage, circuit design and the available 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 its DC interrupting rating as manufacturer self-certified. The available fault current must remain within the applicable interrupting rating.
Current-limiting construction helps reduce the heating and magnetic effects associated with short-circuit events. Rejection-style construction helps prevent the 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. Recommended accessories include compatible L60030C and LPSC/LFPSC Touch-Safe fuse holder families.
We support online purchase of the Littelfuse KLKR-3 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-3?
It is a 3 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 a fast overload response.
What is the manufacturer catalog number?
The manufacturer catalog number is KLKR003. Littelfuse specifies the product marking KLKR 3A and lists KLKR003.T as the manufacturer ordering number for a 10-piece pack.
What is the current rating of KLKR-3?
The rated current is 3 amperes, equivalent to 3000 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 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-3 a fast-acting or time-delay fuse?
KLKR-3 is a fast-acting fuse. It belongs to the KLKR series, which is designed for fast overload protection. The KLDR series has time-delay characteristics and should not be considered electrically identical.
Can KLKR-3 replace a KLDR-3 fuse?
Not automatically. Both are Class CC fuses with a nominal 3 A current rating, but they have different overload response characteristics. Replacement suitability depends on the protected circuit, expected inrush current and applicable protection requirements.
Is KLKR-3 suitable for industrial control transformer circuits?
Littelfuse identifies control transformer circuits among the KLKR series applications where fast overload response is required. The transformer's magnetizing inrush current, circuit design and protective-device coordination must be evaluated before selection.
Does Littelfuse specify an individual total clearing I²t value for KLKR-3?
The KLKR datasheet revised February 25, 2025 provides numerical total clearing I²t values for selected reference ratings but does not list an individual numerical value for KLKR003.T. Values for the 1 A, 6 A or other KLKR ratings must not be substituted for the 3 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 uses a melamine body and nickel-plated bronze end caps. Littelfuse specifies a series weight of 15.42 g for the 1.5 A through 30 A ratings.
Which fuse holders are recommended?
Littelfuse lists the L60030C and LPSC/LFPSC Touch-Safe fuse holder series as accessories. Confirm the holder's Class CC compatibility, voltage rating and electrical capacity before installation.
Is KLKR-3 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 manufacturer self-certified.
What should be verified before ordering KLKR-3?
Confirm the KLKR-3 or KLKR003 designation, 3 A current rating, applicable 600 VAC or 300 VDC circuit requirement, fast-acting characteristics, interrupting capacity, Class CC fuse-holder compatibility and desired purchase quantity. Littelfuse lists KLKR003.T as a manufacturer 10-piece pack ordering number; this does not establish the quantity supplied by an individual store listing.
