HAW569 Surge Arresters Endress+Hauser HAW569 Surge Arresters are easy to install and operate to protect electronic components in field devices from being destroyed. These simple HAW569 devices ensure that overvoltage surges in power lines, signal cables (such as 4mA to 20mA), and fieldbus communication lines (HART, PA, FF) are safely passed into the ground. The functionality of the protected electronic component is not affected because interference voltage drops cannot be introduced thanks to the impedance-free connection of the protection unit. Endress+Hauser HAW569 Surge Arresters are ideally suited for process-related instrumentation in industries and sectors such as oil and gas, food, chemicals, pharmaceuticals, and water and wastewater.