The ULF series from RARA represents a pinnacle in resistor design, boasting a robust metal-clad, wirewound construction that stands out in high-power industrial applications. Encased in an extruded aluminum housing, this series not only ensures rugged protection but also secures UL approval, signifying compliance with stringent safety standards. This UL certification enhances the reliability of the ULF resistors, making them a trusted choice for demanding environments.

In terms of specific features, the ULF resistors showcase a compact and flat design, optimising space utilisation without compromising performance. This unique form factor facilitates excellent heat dissipation, a crucial aspect in industrial settings. With a notable power rating of up to 500W when mounted on a heat sink, these resistors cover a broad resistance range from 1Ω to 2.46kΩ. Customers can tailor their choice between cement or silicone filling materials based on specific application requirements. Operating effectively over a wide temperature range, from -55℃ to 200℃ for cement and -55℃ to 150℃ for silicone, these resistors maintain precise performance. The ULF series exhibits exceptional tolerances as low as ±0.5% and a maximum Temperature Coefficient of Resistance (TCR) of ±260ppm/℃, ensuring reliable and accurate operation in diverse industrial scenarios.

For those seeking a non-UL approved option with similar precision and reliability, the IRF series provides an alternative within RARA’s resistor lineup. Although lacking UL approval, the IRF series shares the outstanding features of its ULF counterpart, making it a viable choice for applications where this certification may not be a primary requirement.