March 12, 2021
SCHURTER’s prominent UMT-H surface mount ceramic fuse family now includes 40 A and 50 A current ratings with an impressive breaking capacity rating of 500 A at 125 VAC / 72 VDC. The series provides unprecedented overcurrent and short circuit protection performance in a package size of 5.3 x 16 mm.
The UMT-H was originally developed to provide a smaller alternative to through-hole mounted 5 x 20 mm cartridge fuses, commonly used for primary circuit protection. The range has since grown to include 26 rated currents from 160 mA to 50 A. Rated voltage is maximum 277 VAC / 250 VDC, with a remarkable interrupt capacity rating of 1500 A for current ratings up to 6.3 A. The Time-Lag T characteristic of the UMT-H withstands high inrush and pulse currents. Its 277 VAC rating is intended for use in circuits using one of 3-phase wiring schemes (480Vac ÷√3=277Vac), common to commercial and industrial lighting in the U.S.
The UMT-H series has evolved to include higher current ratings to meet new markets for secondary protection in battery-powered applications. Areas of application are widespread, from motors to newer emerging applications such as those reliant on energy accumulators and everything in between. The UMT-H is an all-around ideal solution for many applications in energy, data, medical, industrial control and automotive to name a few. It is also impermeable to conformal coatings, and thus a good candidate for use in ATEx and IECEx rated devices for hazardous environments.
A variety of breaking capacity measurements are performed on the UMT-H at specific solder trace widths. The information is provided on the datasheet to help guide in accurate selection and circuit installation. The admissible ambient temperature range is -55°C to 125°C. Large solder pads ensure optimal heat dissipation. The fuse is available in 100-piece quantities loose, or 1500-piece reels for automated pick and place.
The UMT-H is designed according to IEC 60127-7 and UL 248-14 and carries VDE and cURus approvals. IEC and MIL-STD 202 tests apply. Pricing starts at about $1.30 each per reel of 1500 pieces.