Littelfuse NLN020 NLN Series C...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$3.04
Littelfuse NLN020 NLN Series Class K5 Cartridge Fuse, 20A

Littelfuse NLN020 NLN Series Class K5 Cartridge Fuse, 20A

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Model: NLN020

In Stock (leaves warehouse same day if ordered before 3pm ET)

$3.04
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Littelfuse NLN020 NLN Series Class K5 Cartridge Fuse, 20A

The Littelfuse NLN020 NLN Series Class K5 Cartridge Fuse delivers low-cost, general-purpose overcurrent protection for feeder and branch circuits in residential, commercial, and industrial applications. Rated 250VAC and 250VDC at 20A with a 50,000 ampere interrupting rating, this fast-acting, non-time-delay fuse is packaged in an industrial cartridge format and is engineered to replace Class H fuses, which carry only a 10,000 ampere interrupting rating. NLN Series fuses are best suited to circuits with little or no motor load, including resistive heating loads, where lowest initial cost is the primary consideration.

Key Features

  • Ampere Rating: 20A rating sized for general-purpose feeder and branch circuit protection.
  • Voltage Rating: Rated 250VAC and 250VDC for use across compatible AC and DC circuits.
  • Fast-Acting Opening: Fast-Acting (F) response characteristic for non-time-delay overcurrent protection.
  • Class K5, 50,000 A.I.R.: Delivers a 50,000 ampere interrupting rating, a major upgrade over Class H fuses limited to 10,000 amperes.
  • Industrial Cartridge Package: Housed in an industrial cartridge form factor for standard fuse holder and clip compatibility.
  • Cost-Effective Protection: Engineered for applications where lowest initial cost is the primary consideration.
  • Broad Application Range: Suitable for residential and smaller commercial or industrial circuits with little or no motor load, including resistive heating loads.

Certifications & Compliance

  • UL Listed (UL File E81895)
  • CSA Certified (CSA 1421-01-029862 and CSA 1422-02-029862)
  • CE Compliant

Technical Specifications

  • VAC (V): 250
  • VDC (V): 250
  • Ampere Rating (A): 20

Typical Applications

  • Residential Feeder and Branch Circuit Protection
  • Smaller Commercial and Industrial Electrical Systems
  • General-Purpose Circuits with Little or No Motor Load
  • Resistive Heating Load Circuits
  • Class H Fuse Replacement Upgrades

Why Littelfuse?

Littelfuse backs the NLN Series with UL Listed, CSA Certified, and CE Compliant documentation, giving electrical professionals confidence in code-compliant overcurrent protection. With a 50,000 ampere interrupting rating and fast-acting performance, the NLN020 delivers dependable, cost-effective circuit protection for everyday residential, commercial, and industrial installations.

Product Specs

Product Type:
Fast-Acting Fuse
Series:
NLN
Voltage Rating:
250V
Amperage Rating:
20A
Configuration:
Fast-Acting
Listing:
UL Listed
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Fuses

Littelfuse NLN020 – Frequently Asked Questions

1) Can the Littelfuse NLN020 replace a Class H fuse in an existing panel?
That is exactly what the NLN Series is built for. The NLN020 is a Class K5 cartridge fuse rated 250V, 20A, and it is engineered to replace Class H fuses while raising the interrupting rating from 10,000 amperes to 50,000 amperes. It drops into the same industrial cartridge holders and clips, so the swap is a straight upgrade in fault-current withstand on the same circuit.
2) Will a 20A NLN fuse hold on a motor circuit, or will it nuisance-blow on inrush?
Use something else. The NLN020 is a fast-acting, non-time-delay fuse, so motor starting inrush will likely open it. The NLN Series is intended for circuits with little or no motor load, such as resistive heating and general-purpose feeders and branches. For motor loads, a time-delay type like the Mersen A2D-R Class RK1 time-delay fuse is the right family to look at.
3) Can I use the NLN020 on a 480V system?
No. The NLN020 tops out at 250VAC and 250VDC, so it is limited to 240V class systems and below. A 480V circuit needs a 600V rated fuse instead.
4) What is the closest alternative to the Littelfuse NLN020 if the circuit has motor load and needs time delay?
The NLN020 is a fast-acting, non-time-delay fuse best suited to circuits with little or no motor load, including resistive heating loads. Where the load is a motor and inrush would open a fast-acting link, the Mersen A2D-R is a Class RK1 time-delay fuse with SmartSpot indication, which gives the delay characteristic the NLN020 does not have. Confirm amperage and holder fit before swapping, since the two are different fuse classes.
5) Is the Mersen A2K1R a direct replacement for the Littelfuse NLN020?
Not a direct one. Both are fast-acting 250V fuses, but the Mersen A2K Series A2K1R is a Class RK1 fuse while the NLN020 is Class K5 rated 250VAC and 250VDC at 20A. Class RK1 uses rejection-style dimensions and a different current-limiting characteristic, so the two are not interchangeable in the same clips or holder without checking the fuse block, and the A2K1R is a 1A rating rather than 20A.
6) Is the Littelfuse NLN020 rated for DC as well as AC?
Both. The NLN020 carries a 250VAC and a 250VDC rating, so it can be applied on DC circuits up to 250 volts as well as 250 volt AC branch and feeder circuits.
7) Is this fuse UL Listed for commercial and institutional work?
The NLN020 is UL Listed under UL File E81895, CSA Certified under CSA 1421-01-029862 and CSA 1422-02-029862, and CE Compliant. That covers the documentation most facility and institutional specs ask for on branch circuit overcurrent protection.
8) What is the difference between Class K5 and Class RK1 fuses for a 250V panel?
Class K5, like the Littelfuse NLN020, is the low initial cost option: fast-acting, 50,000 ampere interrupting rating, suited to general-purpose and resistive loads. Class RK1 fuses, such as the Mersen A2K Series fast-acting 250V fuse or the A2K12R from the A6K-R series, are the rejection-style current-limiting family used where equipment is specified for RK1 protection. If the drawing calls out RK1, the K5 is not a substitute.
9) Will the NLN020 fit standard fuse clips and holders?
It is built in the industrial cartridge form factor, which is what standard fuse holders and clips for 250V cartridge fuses accept. Class K5 uses the same dimensions as Class H in the same amp and voltage range, which is why it works as a direct Class H replacement.
10) Can a Mersen Amp-Trap D0R0 medium voltage fuse be used in place of the Littelfuse NLN020?
No. The Mersen A055F1D0R0-150E is an Amp-Trap E-rated medium voltage fuse with ferrule terminals, intended for medium voltage transformer and feeder applications. The Littelfuse NLN020 is a 250VAC/250VDC, 20A Class K5 industrial cartridge fuse for low voltage feeder and branch circuits. They serve entirely different voltage systems and are not substitutes for each other.
11) Our drawing shows a Class RK1 time-delay fuse but the panel already has Class K5 fuses in it. How do the Littelfuse NLN020 and Mersen A2D-R differ for standardizing a facility?
The NLN020 is Class K5, fast-acting, 250VAC/250VDC at 20A with a 50,000 ampere interrupting rating, UL Listed and CSA Certified. The Mersen A2D-R is Class RK1 with a time-delay characteristic and SmartSpot blown-fuse indication. Standardizing on one class matters because the holder and rejection features differ between Class K5 and Class RK1, so decide the class first and then size amperages across the facility to match.
12) What part number do I order for the 20 amp Littelfuse NLN fuse?
Order NLN020. That is the Littelfuse NLN Series Class K5 cartridge fuse at 20 amps, 250V, fast-acting. The amp rating is carried in the last three digits of the part number.
13) Will the Square D PowerLogic meter fuse pack work for the same job as the Littelfuse NLN020?
No. The Square D EMFP3 is a set of three 0.5A 600V fuses supplied for PowerLogic energy meter voltage-sensing inputs. The Littelfuse NLN020 is a 20A, 250V Class K5 cartridge fuse for feeder and branch circuit overcurrent protection. The amperage and the application are different, so one does not stand in for the other.
How fast can I get the Littelfuse NLN020 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Littelfuse NLN020 come with a warranty?
Absolutely. The Littelfuse NLN020 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Littelfuse NLN020?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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