All models of the PWR220 or PWR263 series, whether thick film or manganin foil technology, are able to dissipate large amounts of power and carry up to 50A of current, provided there is a sufficient thermal path between the resistor, its backplate and the mounting surface. The larger the aluminum heat sink that the resistor can be attached to, the lower the overall thermal resistance and the higher the amount of current that can be carried. The most important condition for operating this range of resistors is to keep the temperature of the backplate at 25°C under power. The maximum surface temperature of the resistor typically should be 155˚C.