Bussmann 170M3445 Class aR Hig...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$1,325.00
Bussmann 170M3445 Class aR High-Speed Square Body Fuse, 250A

Bussmann 170M3445 Class aR High-Speed Square Body Fuse, 250A

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Model: 170M3445

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

$1,325.00
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Bussmann 170M3445 Class aR High-Speed Square Body Fuse, 250A

The Bussmann 170M3445 is an Eaton Bussmann series high-speed square body fuse engineered for semiconductor protection. Rated 700V (UL) and 690V (IEC) at 250A with a 100 kAIC interrupt rating, this Class aR fuse (accompanied semiconductor protection) features a square body design with flush end contacts for secure, reliable connections in demanding power electronics circuits. It is IEC Rated and CE Marked for compliant use in industrial electrical systems.

Key Features

  • High-Speed Class aR Protection: Utilization Category aR (accompanied semiconductor protection) provides fast-acting, current-limiting protection for sensitive semiconductor devices.
  • Electrical Rating: Rated 700V (UL), 690V (IEC), 250A, with a 100 kAIC interrupt rating for high fault-current applications.
  • Square Body Construction: Square body fuse shape with flush end contacts for a compact, secure mounting footprint.
  • Fast Clearing Performance: Clearing I2t rated 54500 at 1000V and 73000 at 1250V, with a pre-arc I2t of 9200 for rapid fault clearing.
  • Compact Dimensions: Measures 60 mm in height, 92 mm in length/depth, and 163 mm in width.
  • Voltage Rating: 1250V AC voltage rating for demanding power system designs.
  • Efficient Operation: 55W watt-loss rating supports efficient thermal performance within the protected circuit.

Certifications & Compliance

  • IEC Rated
  • CE Marked

Technical Specifications

  • Amperage Rating: 250 A
  • Application: semiconductor protection
  • Certifications: IEC Rated
  • Clearing I2t: 54500 at 1000 V, 73000 at 1250 V
  • Compliances: CE Marked
  • Fuse Shape: Square body, flush end contacts
  • Insulated Metal Gripping Lugs (Imgl): No
  • Packaging Type: Standard
  • Pre Arc I2t: 9200
  • Product Height: 60 mm
  • Product Length Depth: 92 mm
  • Product Weight: .885 g
  • Product Width: 163 mm
  • Utilization Category: aR (accompanied semiconductor protection)
  • Voltage Rating: 1250 V
  • Voltage Type: AC
  • Watt Losses: 55 W

Typical Applications

  • Semiconductor Protection Circuits
  • Power Electronics and Motor Drives
  • Industrial Motor Control Systems
  • High Fault-Current Electrical Systems
  • Panelboard and Switchgear Protection

Why Bussmann?

Bussmann by Eaton is a recognized name in circuit protection, and the 170M3445 reflects that engineering standard with its Class aR high-speed design, precise clearing I2t performance data, and IEC Rated, CE Marked compliance. For engineers specifying semiconductor protection in demanding industrial power systems, this fuse delivers dependable, code-compliant performance.

Manufacturer Resources

Product Specs

Amperage Rating:
250 A
Application:
semiconductor protection
Certifications:
IEC Rated
Class:
Class aR
Clearing I2t:
54500 at 1000 V, 73000 at 1250 V
Compliances:
CE Marked
Fuse Indicator:
Other
Fuse Shape:
Square body, flush end contacts
Insulated Metal Gripping Lugs Imgl:
No
Interrupt Rating:
100 kAIC
Mounting Method:
Flush
Packaging Type:
Standard
Pre Arc I2t:
9200
Product Height:
60 mm
Product Length Depth:
92 mm
Product Weight:
.885 g
Product Width:
163 mm
Utilization Category:
aR (accompanied semiconductor protection)
Voltage Rating:
1250 V
Voltage Type:
AC
Watt Losses:
55 W
Product Group:
Fuses
Department:
Electrical
Product Subgroup:
Other Fuses
Product Type:
Fuse
Product Details:
Fuse

Bussmann 170M3445 – Frequently Asked Questions

1) Can a Bussmann 170M3445 fuse protect the diodes and IGBTs in a motor drive, or do I need a different class?
Semiconductor protection is exactly what the 170M3445 is built for. It is a Class aR fuse, utilization category aR (accompanied semiconductor protection), which means it is a fast-acting current-limiting element intended to sit alongside other protection in the circuit and clear a fault fast enough to save the rectifier diodes, SCRs or IGBTs downstream. Pre-arc I2t is 9200 and clearing I2t is 54500 at 1000V, so you can check it against the I2t withstand figure on your semiconductor datasheet. If you need full-range protection including low-level overloads on cable and general circuits, a gR/gS or standard branch-circuit fuse is the right type instead.
2) What voltage and current is the Bussmann 170M3445 rated for?
250 amps, on a fuse rated 1250 V AC. The interrupting rating is 100 kAIC, so it holds up on stiff industrial services and drive front ends where available fault current is high. The listing also states 700V UL and 690V IEC ratings for the 170M3445, which are the figures you cite on a UL or IEC-compliant panel submittal.
3) Will the 170M3445 square body fuse bolt into my existing holder, or does it clip in?
It mounts flush. The 170M3445 is a square body fuse with flush end contacts, so it bolts directly to busbar or to a flush-contact square body mount, not into spring clips and not into a DIN-rail cylindrical holder. Body dimensions are 60 mm height, 92 mm length/depth and 163 mm width, so lay that footprint against your mounting centers before committing. It does not have insulated metal gripping lugs, so if your panel requires IMGL-style insulated lug terminations you need a different version.
4) How much heat does a 250A Bussmann 170M3445 fuse put into the enclosure?
Watt loss is rated at 55 W per fuse at full load. On a three-phase set that is roughly 165 W of heat inside the cabinet, which is a number you want in your enclosure thermal calculation if the panel is sealed or fan-cooled rather than louvered.
5) Is the Bussmann 170M3445 acceptable on equipment being built for export to Europe?
Yes. The 170M3445 is IEC Rated and CE Marked, which is what a machine builder or panel shop needs for a CE-declared assembly. It also carries a UL voltage rating of 700V alongside the 690V IEC figure, so the same part can appear on both a North American and a European build of the same panel.
6) What is the difference between the clearing I2t figures at 1000V and 1250V on this fuse?
Clearing I2t on the 170M3445 is 54500 at 1000 V and 73000 at 1250 V. Let-through energy rises with applied voltage, so when you coordinate against a semiconductor's I2t withstand you must use the figure for the actual circuit voltage, not the lower one. Pre-arc I2t is 9200, the melting energy before the arc begins.
7) What part number do I order for this Bussmann high-speed fuse, and does it have a blown indicator?
Order by Eaton Bussmann MPN 170M3445. It ships in standard packaging, single fuse. The fuse indicator is listed as other, meaning it is not a standard striker or visual-indicator version, so if your switchgear depends on a microswitch striker pin to trip a drive or signal an alarm, specify a striker version of the 170M series rather than this one.
How fast can I get the Bussmann 170M3445 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 170M3445 come with a warranty?
Absolutely. The Bussmann 170M3445 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 170M3445?
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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