Bussmann KTN-R Eaton LIMITRON Fast-Acting Fuse, Class RK1

The KTN-R LIMITRON fast-acting fuse is offered in 1, 3, 10, 25, 30, 35 and 60 amp ratings, ordered as KTN-R-1, KTN-R-3, KTN-R-10, KTN-R-25, KTN-R-30, KTN-R-35 and KTN-R-60. All of them are 250 V rated, so the amp rating is the only thing you pick.

No. The KTN-R is a 250 V fuse and must not be applied above that. For 600 V service you need the 600 V Class RK1 equivalent, the Bussmann KTS-R, which is the same LIMITRON fast-acting design at the higher voltage rating.

Yes on the holder. The KTN-R is a Class RK1 fuse built to the standard rejection-type dimensions, so it drops into Class R holders and clips that accept RK1 or RK5. The reverse is not true: a rejection Class R holder will not accept a non-rejection Class H or K fuse. Up through 60 A these are ferrule end x ferrule end, so they clip in rather than bolt.

KTN-R is a fast-acting fuse with only minimal time delay, which is what you want for protecting non-inductive loads and equipment that needs a fast clearing time, such as panelboard feeders and circuits with no large inrush. A motor with a heavy starting current will nuisance-blow a fast-acting fuse sized to the running load; for motor branch circuits use a dual-element time-delay Class RK1 fuse such as the Bussmann LPN-RK (250 V) instead.

The 1 amp KTN-R measures 2 x 0.56 x 0.56 inches, the standard small-ferrule Class R body. Larger amp ratings in the series step up in case size, so confirm your clip spacing matches the rating you order rather than assuming the 1 A dimensions carry across.

Yes. KTN-R-30 is the genuine Bussmann (Eaton) part number for the 30 amp, 250 V LIMITRON fast-acting Class RK1 fuse. The numbering runs KTN-R plus the amp rating, so KTN-R-60 is the 60 amp version of the same fuse.

No, it is non-indicating. There is no window or pop-out pin, so troubleshooting means pulling the fuse and testing continuity, or metering across the clips. If maintenance crews need to spot an open fuse by eye, specify an indicating fuse or add an external blown-fuse indicator at the panel.

A melamine glass tube body with a single fusible element inside. That construction is what handles the arc energy and pressure during interruption, and it is why the fuse is not re-fillable or serviceable, it gets replaced as a unit.

Standard packaging, sold by amp rating. For MRO stocking it is worth holding the ratings that match your panel schedules, since the KTN-R line covers 1 through 60 A in seven ratings and a single-element fast-acting fuse cannot be substituted with a time-delay type without changing the protection characteristic.