Bussmann 170M1421 Eaton Series...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$370.94
Bussmann 170M1421 Eaton Series High Speed Square Body Fuse, 250A Class aR

Bussmann 170M1421 Eaton Series High Speed Square Body Fuse, 250A Class aR

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Model: 170M1421

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

$370.94
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Bussmann 170M1421 Eaton Series High Speed Square Body Fuse, 250A Class aR

The Bussmann 170M1421 Eaton series high speed square body fuse is engineered for reliable semiconductor protection in demanding industrial power circuits. Rated 700V (UL) and 690V (IEC) at 250A with a 200 kAIC interrupt rating, this Class aR fuse uses a blade end X blade end termination in a DIN 43 620 square body footprint. Designed for accompanied semiconductor protection (Utilization Category aR), it is UL Recognized and CE Marked for use in coordinated power electronics and industrial equipment applications.

Key Features

  • Amperage Rating: 250A fuse rating for dependable overcurrent protection in semiconductor circuits.
  • Voltage Rating: 700V (UL) and 690V (IEC) dual-standard voltage rating for global design compliance.
  • Interrupt Rating: 200 kAIC interrupting capacity supports demanding high fault-current applications.
  • Utilization Category aR: Class aR design provides accompanied semiconductor protection coordinated with power semiconductor devices.
  • Square Body Construction: DIN 43 620 square body with slotted offset bolted tags and blade end X blade end termination for secure, repeatable mounting.
  • Clearing & Pre-Arc I2t: Clearing I2t of 51500 at 660V and Pre-Arc I2t of 7750 for predictable, precise current-limiting performance.
  • Watt Losses: 42W power dissipation rating for accurate thermal design considerations.

Certifications & Compliance

  • UL Recognized
  • CE Marked

Technical Specifications

  • Amperage Rating: 250 A
  • Application: semiconductor protection
  • Certifications: UL Recognized
  • Clearing I2t: 51500 at 660 V
  • Compliances: CE Marked
  • Fuse Shape: Square body, slotted offset bolted tags
  • Insulated Metal Gripping Lugs (Imgl): No
  • Packaging Type: Standard
  • Pre Arc I2t: 7750
  • Product Height: 53 mm
  • Product Length Depth: 100 mm
  • Product Weight: 136.4 g
  • Product Width: 21 mm
  • Utilization Category: aR (accompanied semiconductor protection)
  • Voltage Rating: 690 V
  • Voltage Type: AC
  • Watt Losses: 42 W

Typical Applications

  • Semiconductor Protection Circuits
  • Power Electronics and Rectifier Equipment
  • Motor Drives and Variable Frequency Drives
  • Industrial Power Conversion Systems
  • Switchgear and Panelboard Coordination

Why Bussmann?

Bussmann by Eaton is engineered to deliver coordinated, code-compliant circuit protection for demanding industrial power systems. The 170M1421 reflects that standard with its UL Recognized and CE Marked compliance, Class aR utilization category, and precisely tested clearing and pre-arc I2t characteristics that ensure predictable current-limiting performance. For professionals specifying semiconductor protection fuses, Bussmann provides the reliability and design consistency that industrial power electronics applications require.

Manufacturer Resources

Product Specs

Amperage Rating:
250 A
Application:
semiconductor protection
Certifications:
UL Recognized
Class:
Class aR
Clearing I2t:
51500 at 660 V
Compliances:
CE Marked
Connection:
Blade end x blade end
Fuse Indicator:
Other
Fuse Shape:
Square body, slotted offset bolted tags
Insulated Metal Gripping Lugs Imgl:
No
Interrupt Rating:
200 kAIC
Mounting Method:
DIN 43 620
Packaging Type:
Standard
Pre Arc I2t:
7750
Product Height:
53 mm
Product Length Depth:
100 mm
Product Weight:
136.4 g
Product Width:
21 mm
Utilization Category:
aR (accompanied semiconductor protection)
Voltage Rating:
690 V
Voltage Type:
AC
Watt Losses:
42 W
Product Group:
Fuses
Department:
Electrical
Product Subgroup:
Other Fuses
Product Type:
Fuse
Product Details:
Fuse

Bussmann 170M1421 – Frequently Asked Questions

1) Will a Bussmann 170M1421 fuse protect my drive's IGBTs, or do I still need a branch circuit fuse?
The 170M1421 is a Class aR fuse, which is accompanied semiconductor protection. It clears short circuits fast enough to save the semiconductors, but it is not intended to stand alone as the overload device. Pair it with an upstream branch circuit protective device that handles overload and general circuit protection. Its stated application is semiconductor protection in power electronics, rectifiers and motor drives.
2) What voltage and current is the Bussmann 170M1421 square body fuse rated for?
250 A at 690 V AC per IEC, and 700 V under UL. Interrupting capacity is 200 kAIC, so it can sit on a stiff industrial bus with high available fault current. If your drive DC link or rectifier section runs above those voltages, this is the wrong ampere/voltage combination for that circuit.
3) Will the 170M1421 bolt into my existing DIN 43 620 fuse base?
Yes. It is a DIN 43 620 square body fuse with slotted offset bolted tags, blade end by blade end. That is the standard square body mounting pattern used on most European-style semiconductor fuse holders and bus bar mounts. Body measures 100 x 53 x 21 mm, so confirm you have that envelope between barriers.
4) What I2t values do I use to coordinate the 170M1421 with my rectifier diodes?
Clearing I2t is 51,500 at 660 V and pre-arc I2t is 7,750. Compare the clearing value against the I2t withstand of the diode or thyristor you are protecting: the device rating must exceed the fuse's let-through at your applied voltage. Pre-arc is what you use when coordinating against another fuse upstream or downstream for selectivity.
5) Can I use a standard Class J or RK5 fuse instead of the 170M1421 in a drive?
No. Class J and RK5 are branch circuit fuses with much slower let-through; they will not clear fast enough to protect power semiconductors, and their bodies do not match the DIN 43 620 square body mounting with blade tags. For semiconductor protection you need a high speed aR fuse like this one, with a published clearing I2t (51,500 at 660 V here) you can check against the device rating.
6) How much heat does a 250A Bussmann 170M1421 fuse put into the enclosure?
Watt loss is 42 W at rating. Multiply by the number of fuses in the cabinet when you size ventilation or the cooling load, and remember square body fuses need free air around the tags to hit their published loss figures. If your panel is sealed, that 42 W per fuse is real heat you have to move.
7) Does the Bussmann 170M1421 have a blown fuse indicator or microswitch?
There is no striker pin or microswitch option on this one, and no insulated metal gripping lugs. If your panel relies on a mechanical indicator to trip an alarm contact, you will need a different 170M variant that carries the indicator/microswitch suffix rather than this bare-tag version.
8) Is the Bussmann 170M1421 approved for equipment built for both North America and Europe?
It carries UL Recognition and a CE mark, with dual voltage ratings of 700 V UL and 690 V IEC. That combination is what OEMs building one panel for both markets are usually after. UL Recognized means it is approved as a component inside listed equipment rather than as a standalone listed device.
9) What is the exact part number and weight for ordering and freight on this Bussmann high speed fuse?
Order as Bussmann (Eaton) 170M1421. Each fuse weighs 136.4 g and ships in standard packaging, so a panel shop ordering a handful of spares is dealing with a light, small parcel item rather than a freight shipment.
How fast can I get the Bussmann 170M1421 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 170M1421 come with a warranty?
Absolutely. The Bussmann 170M1421 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 170M1421?
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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