Littelfuse L25S030 L25S Series...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$18.49
Littelfuse L25S030 L25S Series Semiconductor Fuse, 250V 30A

Littelfuse L25S030 L25S Series Semiconductor Fuse, 250V 30A

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Model: L25S030

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

$18.49
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Littelfuse L25S030 L25S Series Semiconductor Fuse, 250V 30A

The Littelfuse L25S030 L25S Series Semiconductor Fuse delivers extremely fast-acting, current-limiting protection for silicon controlled rectifiers (SCRs), diodes, thyristors, triacs, transistors, and similar solid-state devices used in variable speed drives, power rectifiers, UPS systems, DC power supplies, and a wide range of electronic equipment. Rated 250VAC / 250VDC at 30A with a Very Fast-Acting (FF) opening characteristic, this fuse offers 200,000 A.I.R. and an interrupting rating of 20000A@250VDC, meeting present and future system requirements wherever extremely fast-acting, current-limiting fuses with no time delay are required. It is UL Recognized under the components program of Underwriters Laboratories, Inc., permitting use for supplementary protection in UL Listed equipment.

Key Features

  • Ampere Rating: 30A rating sized for supplementary protection of semiconductor devices.
  • Voltage Rating: 250VAC / 250VDC for flexible AC and DC circuit protection.
  • Opening Characteristic: Very Fast-Acting (FF) with no time delay, ideal for SCRs, diodes, thyristors, triacs, and transistors.
  • Interrupting Rating: 200,000 A.I.R. (20000A@250VDC) for reliable interruption of overcurrents up to system limits.
  • Extremely Current Limiting: Low I2t and peak let-through currents help meet demanding semiconductor protection requirements.
  • Listing: UL Recognized component suitable for supplementary protection in UL Listed equipment.

Certifications & Compliance

  • UL Recognized Component (Underwriters Laboratories)
  • CSA Certified (1422-30-029862)
  • CE Compliant

Technical Specifications

  • VAC (V): 250
  • VDC (V): 250
  • Ampere Rating (A): 30
  • Opening: Very Fast-Acting (FF)
  • Interrupting Rating: 20000A@250VDC

Typical Applications

  • Variable Speed Drives
  • Power Rectifiers
  • UPS Systems
  • DC Power Supplies
  • Supplementary Protection for SCRs, Diodes, Thyristors, Triacs, and Transistors
  • Electronic and Solid-State Power Equipment

Why Littelfuse?

Littelfuse engineers semiconductor fuses using advanced metallurgical, polymer, and materials research combined with mathematical modeling and computerized statistical analysis to deliver accuracy, consistent quality, reliability, and predictable performance. The L25S030 is UL Recognized for supplementary protection in UL Listed equipment, giving specifiers confidence in code-compliant performance for demanding solid-state power applications such as variable speed drives, power rectifiers, and UPS systems.

Product Specs

Product Type:
Semiconductor Fuse
Voltage Rating:
250V
Amperage Rating:
30A
Series:
L25S
Listing:
UL Recognized
Department:
Electrical
Product Group:
Circuit Protection
Product Subgroup:
Fuses

Littelfuse L25S030 – Frequently Asked Questions

1) Can the Littelfuse L25S030 be used on a DC bus, or is it AC only?
Both. The L25S030 is rated 250VAC and 250VDC at 30A, so it works on AC circuits and on DC links like rectifier outputs and UPS battery buses. On the DC side the stated interrupting rating is 20000A at 250VDC; on AC it carries 200,000 A.I.R. Do not apply it above 250V on either system.
2) Will a standard fast-acting 30A fuse protect my SCR drive, or do I need a semiconductor fuse like the L25S030?
A semiconductor fuse is the right part for solid-state devices. The L25S030 has a Very Fast-Acting (FF) characteristic with no time delay and is extremely current limiting, with low I2t and low peak let-through, which is what keeps an SCR, diode, thyristor, triac or transistor from failing before the fuse clears. General-purpose or time-delay fuses let too much energy through for that job. If your load is a motor or transformer with high inrush, a no-time-delay FF fuse is the wrong choice and will nuisance trip.
3) Is the Littelfuse L25S030 UL Listed for branch circuit protection?
No. The L25S030 is a UL Recognized Component, which permits its use for supplementary protection inside UL Listed equipment, not as branch circuit protection. If an inspector needs branch circuit overcurrent protection on that feeder, you need a listed branch circuit fuse or breaker ahead of it and the L25S030 stays downstream protecting the semiconductors. It is also CSA Certified (1422-30-029862) and CE compliant.
4) What is the closest cross-brand alternative to the Littelfuse L25S030 semiconductor fuse?
The Littelfuse L25S030 is a 250V, 30A very fast-acting semiconductor fuse for protecting SCRs, diodes, thyristors, triacs and transistors. On the Bussmann side, the KAW series is also a semiconductor fuse built for the same class of solid-state protection, so it is the nearest brand-for-brand counterpart. Because the L25S030 is specifically a 250VAC/250VDC, 30A device, confirm the Bussmann part number you select carries the same ampere and voltage rating and the same fast-acting characteristic before you substitute it into a drive or rectifier circuit.
5) I need a semiconductor fuse for a 1000VDC bus - can I use the Littelfuse L25S030?
No. The L25S030 is rated 250VAC/250VDC and should not be applied above that voltage. For a 1000VDC circuit, the Bussmann KAX series is a semiconductor fuse offered in a 1000VDC non-indicating configuration, which suits the higher-voltage DC bus found in larger drives and solar or battery systems. Match the ampere rating to your load when you move up in voltage class.
6) What part number do I order for a 30A 250V Littelfuse semiconductor fuse?
The manufacturer part number is L25S030, from the Littelfuse L25S series. In that designation the 250V rating and the 30A rating are both built into the number, so the single MPN covers the whole order.
7) What semiconductor fuses can I use instead of the Littelfuse L25S if I need a higher DC voltage rating?
The L25S is a 250V class, so for higher DC bus voltages look at the Bussmann KAX series, which is a 1000VDC non-indicating semiconductor fuse. Bussmann also offers the KAW series and the SF100X1000HP series semiconductor fuses, and the FBP series in a blade-end, non-indicating style if your holder takes blade terminals rather than the L25S body. Match amperage and the actual circuit voltage before substituting.
8) What should I use instead of the Littelfuse L25S030 if my fuse holder takes blade-end fuses?
The L25S030 is an L25S series semiconductor fuse, so it must drop into the mounting the L25S body is built for. If your equipment uses a blade-end termination instead, the Bussmann FBP series is a non-indicating semiconductor fuse supplied with blade ends, which is the style of alternative to look at. Verify the blade centers and ampere rating against your holder before ordering.
9) Is the Bussmann SF100X1000HP a drop-in replacement for the Littelfuse L25S030?
Treat it as a different device rather than a drop-in. Both are semiconductor fuses, but the Littelfuse L25S030 is a 250VAC/250VDC, 30A part in the L25S series, while the Bussmann SF100X1000HP is a separate semiconductor fuse series with its own body and rating structure. Swapping between them requires confirming voltage class, ampere rating and the physical mounting your equipment uses.
10) What equipment is the L25S030 typically installed in?
Variable speed drives, power rectifiers, UPS systems and DC power supplies are the usual homes for this fuse, protecting the solid-state power section. For an MRO stockroom running drives on 240V service, a 30A L25S030 is a common spare. It is also used broadly in electronic and solid-state power equipment.
11) Does the L25S030 have a blown-fuse indicator?
Nothing in the Littelfuse L25S030 data describes an indicator option, so treat it as a plain fuse body and plan on electrical verification or a separate monitoring contact. If a visual indication style matters on your panel, the Bussmann FBP and KAX series are specifically called out as non-indicating, so they do not solve it either.
How fast can I get the Littelfuse L25S030 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 L25S030 come with a warranty?
Absolutely. The Littelfuse L25S030 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 L25S030?
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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