An overvoltage protection arrangement includes a signal lead, a switch, and a comparator. The signal lead has a device segment and a bus segment. The switch is connected in series between the device segment and the bus segment. The comparator is operably connected to the switch to open the switch in response to sustained application of overvoltage to the bus segment of the signal lead. Aircraft electrical systems and methods of controlling voltage applied to electrical devices in electrical systems are also described.