Direct water-cooled wirewound resistors dissipate up to 9000W
Available in six compact sizes ranging from 38mm by 178mm to 38mm by 410mm, the resistors are designed to save space and increase reliability over standard wirewound resistors, handling 10 times the power of natural-cooled devices in the same size, and two times the power of indirect water-cooled devices. Optimized as load, filter, snubber, and discharge resistors in large drives; HVDC; and battery-management systems for industrial applications, the resistive elements of the DCRF series devices are in direct contact with water and insulated by ceramic tubes, eliminating the need for a heatsink. With almost no or limited external radiation, the resistors increase reliability by limiting the surface temperature, while a safe failure mode prevents leakage in the event of a water-flow shutdown. The DCRF series offers low inductance (< 500 nH for model DCRF 38 x 178 with resistance of 4.7 Ω) and provides a resistance range from 0.56 Ω to 27Ω, with tolerances down to ± 5 %. The devices feature power ratings from 1500 W to 9000 W with a water inlet temperature of 65°C and 8.33 l/min flow rate (deionized water with conductivity < 2 µS/cm). The resistors offer a typical temperature coefficient of 100 ppm/°C and operate over a temperature range of -55 to +120°C.
Vishay Intertechnology – www.vishay.com