High power varistor series designed to operate at temperatures up to 125C

Littelfuse has introduced its first varistor series designed for high power applications that can operate at ambient temperatures up to 125C with 2500V isolation voltage. The HMOV Varistor Series’ high operating temperature is an advance made possible through the use of a new silicone coating technology. Competitive epoxy-coated varistor designs are typically limited to maximum temperatures of just 85C. The series’ high operating temperature makes it possible to reduce end-product production costs by eliminating the need for an additional heat sink or potting process. The combination of high operating temperature, high surge current absorption of up to 10kA (8/20µs), reliability confirmed by a 1000-cycle thermal stress test, and high isolation voltage (2500V) claim to make the series the highest performance radial-leaded varistor series currently on the market. The series is available in disc diameters of 10mm, 14mm and 20mm. “The HMOV Varistor Series combines the ability to operate at ambient temperatures up to 125C with superior surge current handling capability,” said Johnny Chang, Littelfuse product manager for the HMOV Series Varistor line. “That allows it to provide the safest, most reliable, energy-efficient and cost-saving circuit protection solution available for DC and AC applications that require higher power in extremely hot indoor and outdoor environments.”