Littelfuse JLLS003 Class T Fas...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$13.51
Littelfuse JLLS003 Class T Fast-Acting Fuse, 600VAC/300VDC, 3A

Littelfuse JLLS003 Class T Fast-Acting Fuse, 600VAC/300VDC, 3A

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Model: JLLS003

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

$13.51
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Littelfuse JLLS003 Class T Fast-Acting Fuse, 600VAC/300VDC, 3A

Littelfuse's JLLS Series Class T fuse delivers fast-acting overload and short-circuit protection in an extremely compact, current-limiting design, less than one-third the size of comparable Class R fuses. Rated 3A at 600VAC/300VDC with an Industrial Cartridge package size, this fuse is engineered for non-inductive circuits and equipment where panel space is limited. With an interrupting rating of 20,000A@300VDC, it provides reliable protection for individual electric services, meters, and surge-sensitive components such as variable speed drives and rectifiers.

Key Features

  • Compact Class T Design: Industrial Cartridge package size, less than one-third the size of comparable Class R fuses, ideal for space-constrained panels and meter stacks.
  • Ampere Rating: 3A rating suited for individual electric service and meter protection.
  • Voltage Rating: 600VAC / 300VDC rating supports a wide range of industrial and commercial circuits.
  • Fast-Acting Operation: Fast-Acting (F) opening characteristic provides quick overload protection for surge-sensitive components such as variable speed drives and rectifiers.
  • Interrupting Rating: 20,000A@300VDC interrupting rating for reliable clearing of overcurrent conditions.
  • Extremely Current-Limiting: Stops damaging short-circuit current faster than mechanical protective devices; Class T fuses are rated up to 200,000 A.I.R., reducing equipment damage from the heating and magnetic effects of short-circuit currents.
  • Series Rated Compatibility: Increases the interrupting ratings of molded case circuit breaker load centers and panelboards when series rated with Littelfuse Class T fuses; refer to panelboard manufacturer literature for UL Listed combinations.

Certifications & Compliance

  • UL Listed
  • CSA Certified

Technical Specifications

  • VAC (V): 600
  • VDC (V): 300
  • Ampere Rating (A): 3

Typical Applications

  • Protection of Individual Electric Services and Meters
  • Meter Stack Protection via Main Switches Containing Class T Fuses
  • Input/Output Protection for Variable Speed Drives and Rectifiers
  • Series-Rated Molded Case Circuit Breaker Panelboards
  • Commercial and Industrial Electrical Panels

Why Littelfuse?

Littelfuse Class T fuses combine an extremely current-limiting, fast-acting design with a compact Industrial Cartridge package, giving electrical professionals reliable, code-compliant overcurrent protection without sacrificing panel space. Backed by UL Listing and CSA Certification, the JLLS Series is built for demanding commercial and industrial applications where dependable interruption performance is critical.

Product Specs

Product Type:
Fast-Acting Fuse
Voltage Rating:
600V
Amperage Rating:
3A
Series:
JLLS
Listing:
UL Listed
Standards:
CSA Certified
Configuration:
Fast-Acting
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Fuses

Littelfuse JLLS003 – Frequently Asked Questions

1) Will a Littelfuse JLLS003 fuse fit a standard Class T fuse block or holder?
The JLLS003 is a Class T fuse in an Industrial Cartridge package, so it mounts in Class T blocks, holders and switches rated for 600VAC. Class T dimensions are not interchangeable with Class R or Class J, so a Class R block will not accept it. The payoff is space: Class T bodies run less than one third the size of comparable Class R fuses, which is why they show up in tight meter stacks and panels.
2) Can I use the Littelfuse JLLS003 on a 300V DC circuit as well as 600V AC?
Yes, it carries a dual rating: 600VAC and 300VDC. On the DC side the interrupting rating is 20,000A at 300VDC. Do not apply it above 300V DC, the DC rating is the limiting one.
3) Is a fast-acting Class T fuse the right choice for a motor circuit, or do I need a time-delay fuse?
The JLLS Series is a fast-acting (F) fuse, engineered for non-inductive circuits. Motor circuits draw heavy inrush at start, so a fast-acting 3A fuse will nuisance-open. Use fast-acting where you are protecting surge-sensitive electronics such as variable speed drives and rectifiers, individual electric services and meters. For motor branch circuits, specify a time-delay fuse instead.
4) Is the Littelfuse JLLS003 UL Listed and CSA approved for a commercial panel inspection?
Both. The JLLS003 is UL Listed and CSA Certified, which is what an inspector or a facility spec will typically require for overcurrent protection in commercial and industrial panels.
5) Can Class T fuses raise the interrupting rating of my molded case breaker panelboard?
That is one of the main reasons people specify them. Littelfuse Class T fuses increase the interrupting ratings of molded case circuit breaker load centers and panelboards when series rated with them. The combination has to be a UL Listed one, so check the panelboard manufacturer's literature for the approved series-rated pairings before you build it that way.
6) What exact part number do I order for the 3 amp Littelfuse Class T fuse?
Order JLLS003. That is the 3A rating in the Littelfuse JLLS Class T series at 600VAC/300VDC. The series uses the amp rating in the suffix, so keep the leading zeros when you quote it to avoid getting a 30A fuse.
7) Will a 3A fuse like the JLLS003 work for protecting a variable speed drive?
The fast-acting characteristic is suited to drive and rectifier input/output protection, where the semiconductors need to be cleared quickly. The 3A rating only fits a small drive or a control-side circuit, so size the fuse to the drive manufacturer's recommended fuse ampacity, the JLLS series runs other amp ratings for larger units.
8) What does current-limiting mean on a Class T fuse, and why does it matter for my equipment?
A current-limiting fuse clears a short circuit before the fault current reaches its full prospective peak. The Class T design stops damaging short-circuit current faster than a mechanical protective device, which cuts the heating and magnetic stress on downstream gear such as busbars, meter sockets and drive input sections. Class T fuses are rated up to 200,000 A.I.R.
How fast can I get the Littelfuse JLLS003 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 JLLS003 come with a warranty?
Absolutely. The Littelfuse JLLS003 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 JLLS003?
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
Why buy the Littelfuse JLLS003 from ZenSupply?
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