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Technical specifications, features, applications and purchasing information.
| Brand | Littelfuse |
| Model Number | KLDR-1-1/4 |
| Manufacturer Catalog Number | KLDR1.25 |
| Product Marking | KLDR 1 1/4 A |
| Product Category | Class CC Time-Delay Fuse |
| Product Series | POWR-GARD KLDR |
| Current Rating | 1.25 A (1250 mA, 1-1/4 A) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Fuse Class | UL Class CC |
| Operating Characteristic | Time-Delay |
The Littelfuse KLDR-1-1/4 provides a 1.25 ampere current rating for appropriately specified industrial control circuits, transformer primary circuits and inductive electrical equipment. Its 1250 mA rating supports applications requiring Class CC time-delay overcurrent protection.
Rated for compatible electrical circuits up to 600 VAC or 300 VDC. Separate AC and DC interrupting ratings support application-specific selection according to operating voltage and available prospective fault current.
Designed to accommodate temporary magnetizing inrush currents associated with control transformers, solenoids and similar inductive components. The UL opening-time requirement specifies a minimum of 12 seconds at 200% of rated current rather than a fixed clearing time.
Provides a 200 kA RMS symmetrical AC interrupting rating and a separate 20 kA DC interrupting rating. Littelfuse identifies the DC rating as self-certified. Both ratings should be evaluated against the prospective short-circuit current of the installation.
The current-limiting design helps reduce thermal and magnetic effects during short-circuit events. Its rejection feature helps prevent installation of unsuitable lower-voltage or lower-interrupting-rated fuses when used with corresponding rejection-type holders.
Features a melamine body, nickel-plated bronze caps and a nominal 10.3 x 38.1 mm cartridge format. Compatible mounting accessories include appropriately rated Littelfuse L60030C, LPSC/LFPSC, LEC and 571/572 fuse holders.
We support online purchase of the Littelfuse KLDR-1-1/4 Class CC Time-Delay 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. Confirm the required purchase quantity and packaging configuration before ordering.
What is the Littelfuse KLDR-1-1/4?
It is a 1.25 A Class CC time-delay, current-limiting cartridge fuse from the Littelfuse POWR-GARD KLDR series. The fuse is designed for compatible control transformers, solenoids and other industrial control applications.
What is the manufacturer catalog number?
Littelfuse identifies the 1-1/4 A version under manufacturer catalog number KLDR1.25. The product marking is KLDR 1 1/4 A.
What is the current rating?
The rated current is 1.25 amperes, equivalent to 1250 milliamperes or one and one-quarter amperes.
What are the AC and DC voltage ratings?
The manufacturer specifies 600 VAC and 300 VDC. Confirm that the intended circuit is within the appropriate voltage rating and installation requirements.
What are the AC and DC interrupting ratings?
The AC interrupting rating is 200,000 amperes RMS symmetrical at 600 VAC. The DC interrupting rating is 20,000 amperes at 300 VDC and is identified by Littelfuse as self-certified.
Is KLDR-1-1/4 a time-delay or fast-acting fuse?
KLDR-1-1/4 is a time-delay fuse. The KLDR series is designed to accommodate temporary magnetizing inrush currents associated with control transformers, solenoids and similar inductive components.
Does KLDR-1-1/4 open in exactly 12 seconds at twice the rated current?
No. The UL agency requirement specifies a minimum opening time of 12 seconds at 200% of rated current. This is not a fixed opening time. Consult the manufacturer's time-current curves to evaluate actual circuit protection behavior.
What are the pre-arcing and total clearing I²t values?
Littelfuse specifies a pre-arcing I²t value of 0.4367 A²s and a total clearing I²t value of 7.354 A²s. The total clearing value is listed under the manufacturer's 200 kA test condition.
What are the physical dimensions?
The nominal cartridge dimensions are 10.3 mm in diameter and 38.1 mm in length, approximately 0.41 inch by 1.50 inches.
What materials and fuse holders are used?
Littelfuse specifies a melamine body with nickel-plated bronze caps. Recommended compatible holder families include L60030C, LPSC/LFPSC, LEC and 571/572. The specific fuse holder must meet the application's electrical and mechanical requirements.
Is KLDR-1-1/4 UL listed and RoHS compliant?
The manufacturer identifies the KLDR series as UL Listed under file E81895, CSA Certified under file LR29862 and RoHS compliant. The datasheet also references a CE declaration. Its DC interrupting rating is manufacturer self-certified.
What should be verified before ordering?
Confirm the KLDR-1-1/4 or KLDR1.25 designation, 1.25 A current rating, applicable 600 VAC or 300 VDC requirement, AC or DC interrupting capacity, time-delay characteristics, fuse-holder compatibility and purchase quantity. Littelfuse lists KLDR1.25TXP for a 10-piece manufacturer pack and KLDR1.25HXP for a 100-piece manufacturer pack; these ordering codes do not determine the quantity supplied in an individual store listing.
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| Brand | Littelfuse |
| Model Number | KLDR-1-1/4 |
| Manufacturer Catalog Number | KLDR1.25 |
| Product Marking | KLDR 1 1/4 A |
| Product Category | Class CC Time-Delay Fuse |
| Product Series | POWR-GARD KLDR |
| Current Rating | 1.25 A (1250 mA, 1-1/4 A) |
| AC Voltage Rating | 600 VAC |
| DC Voltage Rating | 300 VDC |
| Fuse Class | UL Class CC |
| Operating Characteristic | Time-Delay |
The Littelfuse KLDR-1-1/4 provides a 1.25 ampere current rating for appropriately specified industrial control circuits, transformer primary circuits and inductive electrical equipment. Its 1250 mA rating supports applications requiring Class CC time-delay overcurrent protection.
Rated for compatible electrical circuits up to 600 VAC or 300 VDC. Separate AC and DC interrupting ratings support application-specific selection according to operating voltage and available prospective fault current.
Designed to accommodate temporary magnetizing inrush currents associated with control transformers, solenoids and similar inductive components. The UL opening-time requirement specifies a minimum of 12 seconds at 200% of rated current rather than a fixed clearing time.
Provides a 200 kA RMS symmetrical AC interrupting rating and a separate 20 kA DC interrupting rating. Littelfuse identifies the DC rating as self-certified. Both ratings should be evaluated against the prospective short-circuit current of the installation.
The current-limiting design helps reduce thermal and magnetic effects during short-circuit events. Its rejection feature helps prevent installation of unsuitable lower-voltage or lower-interrupting-rated fuses when used with corresponding rejection-type holders.
Features a melamine body, nickel-plated bronze caps and a nominal 10.3 x 38.1 mm cartridge format. Compatible mounting accessories include appropriately rated Littelfuse L60030C, LPSC/LFPSC, LEC and 571/572 fuse holders.
We support online purchase of the Littelfuse KLDR-1-1/4 Class CC Time-Delay 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. Confirm the required purchase quantity and packaging configuration before ordering.
What is the Littelfuse KLDR-1-1/4?
It is a 1.25 A Class CC time-delay, current-limiting cartridge fuse from the Littelfuse POWR-GARD KLDR series. The fuse is designed for compatible control transformers, solenoids and other industrial control applications.
What is the manufacturer catalog number?
Littelfuse identifies the 1-1/4 A version under manufacturer catalog number KLDR1.25. The product marking is KLDR 1 1/4 A.
What is the current rating?
The rated current is 1.25 amperes, equivalent to 1250 milliamperes or one and one-quarter amperes.
What are the AC and DC voltage ratings?
The manufacturer specifies 600 VAC and 300 VDC. Confirm that the intended circuit is within the appropriate voltage rating and installation requirements.
What are the AC and DC interrupting ratings?
The AC interrupting rating is 200,000 amperes RMS symmetrical at 600 VAC. The DC interrupting rating is 20,000 amperes at 300 VDC and is identified by Littelfuse as self-certified.
Is KLDR-1-1/4 a time-delay or fast-acting fuse?
KLDR-1-1/4 is a time-delay fuse. The KLDR series is designed to accommodate temporary magnetizing inrush currents associated with control transformers, solenoids and similar inductive components.
Does KLDR-1-1/4 open in exactly 12 seconds at twice the rated current?
No. The UL agency requirement specifies a minimum opening time of 12 seconds at 200% of rated current. This is not a fixed opening time. Consult the manufacturer's time-current curves to evaluate actual circuit protection behavior.
What are the pre-arcing and total clearing I²t values?
Littelfuse specifies a pre-arcing I²t value of 0.4367 A²s and a total clearing I²t value of 7.354 A²s. The total clearing value is listed under the manufacturer's 200 kA test condition.
What are the physical dimensions?
The nominal cartridge dimensions are 10.3 mm in diameter and 38.1 mm in length, approximately 0.41 inch by 1.50 inches.
What materials and fuse holders are used?
Littelfuse specifies a melamine body with nickel-plated bronze caps. Recommended compatible holder families include L60030C, LPSC/LFPSC, LEC and 571/572. The specific fuse holder must meet the application's electrical and mechanical requirements.
Is KLDR-1-1/4 UL listed and RoHS compliant?
The manufacturer identifies the KLDR series as UL Listed under file E81895, CSA Certified under file LR29862 and RoHS compliant. The datasheet also references a CE declaration. Its DC interrupting rating is manufacturer self-certified.
What should be verified before ordering?
Confirm the KLDR-1-1/4 or KLDR1.25 designation, 1.25 A current rating, applicable 600 VAC or 300 VDC requirement, AC or DC interrupting capacity, time-delay characteristics, fuse-holder compatibility and purchase quantity. Littelfuse lists KLDR1.25TXP for a 10-piece manufacturer pack and KLDR1.25HXP for a 100-piece manufacturer pack; these ordering codes do not determine the quantity supplied in an individual store listing.
