Bussmann KAX Series Semiconduc...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$149.34
Bussmann KAX Series Semiconductor Fuse, 1000VDC Non-Indicating

Bussmann KAX Series Semiconductor Fuse, 1000VDC Non-Indicating

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Model: KAX-20

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

$149.34
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Bussmann KAX Series Semiconductor Fuse, 1000VDC Non-Indicating

The Bussmann KAX Series semiconductor fuse from Eaton is engineered to protect sensitive power semiconductor devices — including SCRs, diodes, and IGBTs — from damaging overcurrent and short-circuit conditions in DC power circuits. Rated at 1000Vdc, this Standard, Non-Indicating fuse series delivers fast-acting overcurrent protection for demanding industrial electrical systems where precise semiconductor protection is critical to equipment uptime. The KAX series is available in amp ratings from 2A to 25A (2A, 3A, 5A, 8A, 20A, and 25A), giving engineers and panel builders the flexibility to match fuse protection precisely to circuit load requirements without over-fusing or under-protecting sensitive components. Backed by Eaton's Bussmann manufacturing standards, these fuses provide dependable, code-compliant protection for critical DC power conversion equipment, drive systems, and industrial control panels.

Key Features

  • Voltage Rating: 1000Vdc rating supports demanding DC power semiconductor circuit protection applications.
  • Amp Rating Range: Available in 2A, 3A, 5A, 8A, 20A, and 25A ratings, allowing precise selection to match a wide range of circuit loads.
  • Fuse Style: Standard, Non-Indicating construction provides dependable semiconductor overcurrent protection without a visual trip indicator.
  • Series Design: Part of the Eaton Bussmann KAX semiconductor fuse series, purpose-built for power semiconductor device protection.
  • Application-Specific Protection: Engineered specifically to protect power semiconductor devices such as SCRs, diodes, and IGBTs from damaging overcurrent and short-circuit conditions.
  • Industrial-Grade Reliability: Manufactured under the Eaton Bussmann brand, a long-established name in circuit protection products for industrial and commercial electrical systems.

Technical Specifications

  • Product Length Depth: .56 in
  • Product Weight: .47 lb
  • Product Width: .56 in
  • Compliances: Contact factory
  • Product Height: 2 in

Typical Applications

  • Power Semiconductor Device Protection (SCRs, Diodes, IGBTs)
  • DC Drive and Power Conversion Systems
  • Industrial Motor Control Circuits
  • Renewable Energy and DC Power Systems
  • Panelboard and Switchgear Overcurrent Protection
  • Industrial Control Panel Design and Retrofits

Why Bussmann?

Eaton's Bussmann KAX Series semiconductor fuses are built to protect critical DC power semiconductor equipment with Standard, Non-Indicating construction rated to 1000Vdc. With amp ratings spanning 2A to 25A, the KAX series gives specifiers and panel builders a reliable, code-compliant option for protecting power semiconductor devices across a wide range of industrial DC applications. Choosing Bussmann means specifying circuit protection from a manufacturer trusted across industrial and commercial electrical projects.

Manufacturer Resources

Product Specs

Packaging Type:
Standard
Department:
Electrical
Fuse Indicator:
Non Indicating
Product Length Depth:
.56 in
Product Weight:
.47 lb
Product Width:
.56 in
Compliances:
Contact factory
Product Height:
2 in
Product Type:
Semiconductor Fuse
Voltage Rating:
1000VDC
Amperage Rating:
2A - 25A
Series:
KAX
Product Group:
Circuit Protection
Product Subgroup:
Fuses
Product Length:
0.56 in

Bussmann KAX-20 – Frequently Asked Questions

1) Can the Bussmann KAX fuse be used on a 1000V DC bus?
Yes. The KAX Series is rated 1000Vdc, which is why it turns up in DC drives, power conversion equipment and DC renewable systems. It is a DC-rated semiconductor fuse, so size the circuit to that 1000Vdc ceiling rather than assuming an AC rating alongside it.
2) What amp ratings does the Bussmann KAX semiconductor fuse come in?
Six ratings: 2A, 3A, 5A, 8A, 20A and 25A, ordered as KAX-2, KAX-3, KAX-5, KAX-8, KAX-20 and KAX-25. There is no 10A or 15A step in the range, so if your circuit lands between 8A and 20A you will need to decide which side to fuse on or look at another series.
3) Will a KAX fuse fit in my existing fuse holder? What are the body dimensions?
The KAX body measures 2 in by .56 in by .56 in and weighs .47 lb. Check those against your holder or clip spacing before ordering, since a semiconductor fuse of this size will not drop into a standard midget or Class CC block unless the block is dimensioned for it.
4) Can I tell from looking at a KAX fuse whether it has blown?
No. The KAX is non-indicating, so there is no pop-up pin or visual flag to show it has opened. In a panel where a maintenance tech needs to find the open fuse fast, you will be testing with a meter or relying on a microswitch fuse holder instead. If visual indication matters to your MRO crew, specify an indicating fuse series.
5) What semiconductor fuse should I use if my DC bus is only 500V instead of 1000V?
The Bussmann KAX series is rated 1000VDC, so on a 500V DC bus it is rated well above the circuit. If you want a fuse matched closer to that level, the Littelfuse L50S series is a very fast-acting semiconductor fuse rated 500V. For a 700VAC/650VDC circuit, the Littelfuse L70S very fast-acting semiconductor fuse covers that level. Voltage rating on a fuse is a maximum, not a target, so a 1000VDC KAX remains electrically acceptable at lower bus voltages provided the amp rating and interrupting duty suit the circuit.
6) Is the Littelfuse L15S a substitute for a Bussmann KAX fuse?
No. The Littelfuse L15S is a very fast-acting semiconductor fuse rated 150VAC/150VDC, while the Bussmann KAX series is rated 1000VDC. They serve the same class of load - protecting power semiconductors - but the L15S cannot be applied where a 1000VDC fuse is specified. Use the L15S only on low-voltage semiconductor circuits within its own rating.
7) I need a 30A semiconductor fuse - does the Bussmann KAX cover it?
The Bussmann KAX series runs 2A to 25A, offered as 2A, 3A, 5A, 8A, 20A and 25A, so 30A falls above the range. The Littelfuse L25S030 is a 250V 30A semiconductor fuse if your circuit voltage suits 250V. If you need 30A at a higher DC bus voltage, stay within the Littelfuse L50S or L70S families, which are rated 500V and 700VAC/650VDC respectively.
8) Why use a semiconductor fuse like the KAX instead of a standard industrial fuse?
Semiconductor fuses are built to clear faster than the silicon they protect can fail. The KAX is intended for SCRs, diodes and IGBTs in DC circuits, where a conventional time-delay or general-purpose fuse lets enough energy through to destroy the device before it opens. Use the KAX on the DC side of a drive or converter protecting the power devices; use a standard branch-circuit fuse for feeder and motor-circuit duty.
9) What are the alternatives to the Bussmann KAX if 1000VDC is more voltage than I need?
Lower-voltage semiconductor fuses cost you nothing in protection if the bus voltage is lower. From Littelfuse, the L15S Series is rated 150VAC/150VDC, the L50S Series is 500V and the L70S Series is 700VAC/650VDC. For a single 250V 30A position there is also the Littelfuse L25S030. Pick the series whose voltage rating covers your bus and whose amp step matches the device you are protecting.
10) I need more than 25A of semiconductor protection on a DC circuit. Is there an option?
The KAX range tops out at 25A, so it will not cover a larger device. The Littelfuse L25S030 is a 30A semiconductor fuse, though at 250V, so it only substitutes if your bus voltage is within that. Above 25A on a high-voltage DC bus you need a larger-bodied semiconductor fuse, not a KAX.
11) Is the Bussmann KAX fuse the right choice for a solar or battery DC combiner?
It fits that class of work. The 1000Vdc rating lines up with common PV string voltages, and the listed applications include renewable energy and DC power systems along with DC drives, industrial motor control and switchgear overcurrent protection. The limit is amperage: the KAX only goes to 25A, so it suits string-level or control-circuit protection rather than a large combiner output.
12) What is the difference between the Bussmann KAX and the Littelfuse very fast-acting semiconductor fuse series?
The Bussmann KAX is a Standard, Non-Indicating semiconductor fuse rated 1000VDC, offered 2A through 25A. The Littelfuse L15S, L50S and L70S series are described as very fast-acting semiconductor fuses at 150VAC/150VDC, 500V and 700VAC/650VDC. So the practical split is voltage class first - the KAX is the 1000VDC option among these - and after that you match the clearing characteristic your semiconductor device I2t allows.
13) How is the Bussmann KAX fuse packaged for ordering?
Standard packaging, ordered by individual amp rating. Each rating is its own part number (KAX-2 through KAX-25), so a panel build that mixes ratings is several line items rather than one assortment.
How fast can I get the Bussmann KAX-20 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 Bussmann KAX-20 come with a warranty?
Absolutely. The Bussmann KAX-20 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 Bussmann KAX-20?
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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