Technical specifications, features, applications and purchasing information.
| Brand | Littelfuse |
| Model Number | KLKR-3/10 |
| Manufacturer Catalog Number | KLKR.300 |
| Product Marking | KLKR 3/10 A |
| Product Category | Class CC Fast-Acting Fuse |
| Product Series | POWR-GARD KLKR |
| Current Rating | 0.3 A (300 mA, 3/10 A) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Nominal Dimensions | 10.3 x 38.1 mm (0.41 x 1.50 in) |
The Littelfuse KLKR-3/10 features a 0.3 ampere current rating, equivalent to 300 milliamperes or three-tenths of an ampere. This fractional-amperage rating supports applications requiring a specified low-current Class CC fast-acting fuse in industrial electrical equipment and control circuits.
The KLKR series provides a fast-acting response to overload conditions for equipment requiring rapid circuit protection. Unlike the KLDR time-delay series, KLKR fuses are intended for applications where a fast overload response is required. Normal startup and inrush currents must be considered during fuse selection.
The fuse is rated for compatible AC circuits up to 600 VAC and DC circuits up to 300 VDC. Separate AC and DC ratings support protective-device selection according to circuit operating voltage, installation requirements and prospective short-circuit current.
Provides an AC interrupting rating of 200 kA RMS symmetrical and a separate DC interrupting rating of 20 kA. Littelfuse identifies the DC interrupting rating as manufacturer self-certified. Available prospective fault current must remain within the applicable interrupting capacity.
The current-limiting construction 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 corresponding 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. Compatible installation accessories include appropriately rated Littelfuse L60030C and LPSC/LFPSC Touch-Safe fuse holder series.
We support online purchase of the Littelfuse KLKR-3/10 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-3/10?
It is a 0.3 A Class CC fast-acting, current-limiting cartridge fuse from the Littelfuse POWR-GARD KLKR series, intended for general-purpose branch circuit protection and applications requiring fast overload response.
What is the manufacturer catalog number?
The manufacturer catalog number is KLKR.300. Littelfuse specifies the product marking KLKR 3/10 A and lists KLKR.300T as the ordering number for a manufacturer 10-piece pack.
What is the current rating of KLKR-3/10?
The current rating is 0.3 ampere, equivalent to 300 milliamperes or three-tenths of an ampere.
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 rating as self-certified.
Is KLKR-3/10 fast-acting or time-delay?
KLKR-3/10 is a fast-acting fuse. It belongs to the KLKR series, which provides fast overload response. The KLDR series uses a different time-delay characteristic and is not automatically interchangeable.
Can KLKR-3/10 replace a KLDR-3/10 fuse?
Not automatically. Although both belong to the Class CC family and have the same nominal 0.3 A current rating, KLKR is fast-acting while KLDR is time-delay. Replacement suitability depends on the circuit design, normal inrush current and required overcurrent response.
Is KLKR-3/10 suitable for solid-state electrical equipment?
Littelfuse identifies solid-state components among the applications for the KLKR series. Suitability for a particular electronic device must be verified using its protection requirements, expected operating currents and the fuse time-current characteristics.
Does Littelfuse publish a specific I²t value for KLKR-3/10?
The Littelfuse KLKR datasheet revised February 25, 2025 includes time-current curves covering the 3/10 A rating but does not provide an individual numerical total clearing I²t value for KLKR.300 in its electrical specifications table. I²t values for other ampere ratings should not be substituted.
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 13.61 g for ratings from 0.1 A through 1 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-3/10 UL listed and RoHS compliant?
The KLKR series is UL Listed under file E81895 and CSA Certified under file LR29862. The manufacturer 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-3/10?
Confirm the KLKR-3/10 or KLKR.300 designation, 300 mA 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 KLKR.300T 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-3/10 |
| Manufacturer Catalog Number | KLKR.300 |
| Product Marking | KLKR 3/10 A |
| Product Category | Class CC Fast-Acting Fuse |
| Product Series | POWR-GARD KLKR |
| Current Rating | 0.3 A (300 mA, 3/10 A) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Nominal Dimensions | 10.3 x 38.1 mm (0.41 x 1.50 in) |
The Littelfuse KLKR-3/10 features a 0.3 ampere current rating, equivalent to 300 milliamperes or three-tenths of an ampere. This fractional-amperage rating supports applications requiring a specified low-current Class CC fast-acting fuse in industrial electrical equipment and control circuits.
The KLKR series provides a fast-acting response to overload conditions for equipment requiring rapid circuit protection. Unlike the KLDR time-delay series, KLKR fuses are intended for applications where a fast overload response is required. Normal startup and inrush currents must be considered during fuse selection.
The fuse is rated for compatible AC circuits up to 600 VAC and DC circuits up to 300 VDC. Separate AC and DC ratings support protective-device selection according to circuit operating voltage, installation requirements and prospective short-circuit current.
Provides an AC interrupting rating of 200 kA RMS symmetrical and a separate DC interrupting rating of 20 kA. Littelfuse identifies the DC interrupting rating as manufacturer self-certified. Available prospective fault current must remain within the applicable interrupting capacity.
The current-limiting construction 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 corresponding 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. Compatible installation accessories include appropriately rated Littelfuse L60030C and LPSC/LFPSC Touch-Safe fuse holder series.
We support online purchase of the Littelfuse KLKR-3/10 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-3/10?
It is a 0.3 A Class CC fast-acting, current-limiting cartridge fuse from the Littelfuse POWR-GARD KLKR series, intended for general-purpose branch circuit protection and applications requiring fast overload response.
What is the manufacturer catalog number?
The manufacturer catalog number is KLKR.300. Littelfuse specifies the product marking KLKR 3/10 A and lists KLKR.300T as the ordering number for a manufacturer 10-piece pack.
What is the current rating of KLKR-3/10?
The current rating is 0.3 ampere, equivalent to 300 milliamperes or three-tenths of an ampere.
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 rating as self-certified.
Is KLKR-3/10 fast-acting or time-delay?
KLKR-3/10 is a fast-acting fuse. It belongs to the KLKR series, which provides fast overload response. The KLDR series uses a different time-delay characteristic and is not automatically interchangeable.
Can KLKR-3/10 replace a KLDR-3/10 fuse?
Not automatically. Although both belong to the Class CC family and have the same nominal 0.3 A current rating, KLKR is fast-acting while KLDR is time-delay. Replacement suitability depends on the circuit design, normal inrush current and required overcurrent response.
Is KLKR-3/10 suitable for solid-state electrical equipment?
Littelfuse identifies solid-state components among the applications for the KLKR series. Suitability for a particular electronic device must be verified using its protection requirements, expected operating currents and the fuse time-current characteristics.
Does Littelfuse publish a specific I²t value for KLKR-3/10?
The Littelfuse KLKR datasheet revised February 25, 2025 includes time-current curves covering the 3/10 A rating but does not provide an individual numerical total clearing I²t value for KLKR.300 in its electrical specifications table. I²t values for other ampere ratings should not be substituted.
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 13.61 g for ratings from 0.1 A through 1 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-3/10 UL listed and RoHS compliant?
The KLKR series is UL Listed under file E81895 and CSA Certified under file LR29862. The manufacturer 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-3/10?
Confirm the KLKR-3/10 or KLKR.300 designation, 300 mA 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 KLKR.300T for a manufacturer 10-piece pack; this does not establish the quantity supplied by an individual store listing.
