Bussmann 170M4823 Eaton series high speed square body fuse, 700V (UL), 690V (IEC), 25A, 125 kAIC, Other, Fuse, Blade end X Din 43-620 blade end, Class aR, DIN 43 620

Class aR is a partial-range semiconductor protection fuse, and the 170M4823 is built specifically for that job: protecting diodes, SCRs, IGBT stacks and similar power semiconductors in drives, rectifiers and converters. Utilization category is aR (accompanied semiconductor protection), which means it handles short-circuit protection but is not a full-range device, so overload protection has to be provided by something else in the circuit (typically the drive's electronic overload or an upstream breaker). Do not drop one of these in as a general branch-circuit fuse.

It mounts to DIN 43 620, with a square body and slotted center bolted tags, and the end configuration is blade end x DIN 43-620 blade end. That means it bolts directly into a DIN 43 620 base or busbar arrangement rather than clipping into a cylindrical or NH-style holder. If your existing holder is a Class J, Class T or NH/DIN 43 653 base, this fuse will not drop in.

Pre-arcing (melting) I2t is 30 and clearing I2t is 210 at 1000 V. Those are the numbers you coordinate against your semiconductor's I2t withstand rating: the device's published I2t must exceed the fuse's total clearing I2t, or the semiconductor fails before the fuse clears. Watt loss is 7 W, which is what you use for enclosure heat rise calculations when several of these sit in the same cabinet.

Yes, this is the genuine Eaton Bussmann 170M4823, sold under that exact manufacturer part number: 25 A, Class aR, 125 kAIC, square body with DIN 43 620 blade ends. For a like-for-like drive replacement, match the full 170M number rather than just the amp rating, because the 170M series uses the same amperage across several different body sizes and end configurations.

No, and substituting one is the most common way a rectifier gets destroyed. A standard time-delay or dual-element fuse is deliberately slow, while this 170M4823 is a high speed aR semiconductor fuse with a pre-arcing I2t of 30 and total clearing I2t of 210, chosen to clear faster than the silicon can fail. Same 25 A marking, entirely different let-through energy. Replace a semiconductor fuse only with a semiconductor fuse of matching I2t and mounting.

No. The 170M4823 is supplied without IMGL (insulated metal gripping lugs), so there are no insulated grips for handling the fuse in an energized enclosure. Plan on de-energizing and locking out before changing it, and order an IMGL version of the 170M series if your maintenance procedure requires gripping lugs.

Dimensions are 233 x 140 x 66 mm and it weighs 234 g. Square body high speed fuses of this size need clearance around the bolted tags as well as the body itself, so check both the mounting centers on your DIN 43 620 base and the free space above the fuse before you commit to the layout.

Yes. The 170M4823 is IEC rated and CE marked, which is what a machine builder shipping into Europe normally needs on the documentation package. It is an AC-rated device, so it is not intended for DC traction or battery circuits without a DC-specific rating.

Standard packaging, single fuse per part number. For MRO stocking on a drive fleet, count one per phase leg being protected plus spares, since a semiconductor fault usually takes out more than one fuse at a time.