Bussmann 170M6681 Eaton series high speed square body fuse, 700V (UL), 690V (IEC), 1500A, 125 kAIC, Top fuse status indicator, Fuse, Class aR

It's a high speed square body fuse for semiconductor protection, utilization category aR (accompanied semiconductor protection). That means it protects diodes, SCRs and IGBTs in drives, rectifiers and soft starters, and it is a partial-range device: it clears short circuits only, so it has to be backed up by another device for overload protection. It is not a branch circuit or motor overload fuse on its own.

The 170M6681 is a square body fuse with slotted center bolted tags, so it bolts directly to busbar or to a bolted square body base rather than dropping into a clip-style holder. Body size is 168 x 95 x 76 mm, so confirm your base or busbar centers match that footprint before ordering. It does not have insulated metal gripping lugs.

1500 A continuous with a 125 kAIC interrupting rating. The interrupting rating is what matters on a drive input fed from a large transformer: available fault current at the fuse has to be at or below 125 kA for the fuse to be applied correctly.

Yes. The fuse carries a top-mounted status indicator, so a blown element is visible from above the fuse without pulling it from the busbar. That top position is the one to check when you are laying out the enclosure, since a fuse buried under a cover or a close-mounted barrier defeats it. Many top indicators also accept a microswitch for remote signalling, so confirm the switch you intend to use suits this indicator style.

The 170M6681 is rated for AC service. Square body high speed fuses carry separate DC ratings that are not interchangeable with the AC rating, so do not apply this one to a DC bus on the strength of its AC figures.

No. Class aR, which is what the 170M6681 is, is partial range: it interrupts short circuits only and relies on a separate device for overload. A gR or gS high speed fuse is full range and handles overloads as well, and an aM fuse is a motor-rated back-up device, not a semiconductor fuse. If your drive manual calls for a full range semiconductor fuse, an aR is not a substitute.

Order the Bussmann 170M6681 by that number exactly. The 170M series runs a long block of numbers that differ only in amp rating, body size and indicator position, so a neighbouring number will not necessarily bolt into the same base or match the I2t your semiconductor needs.