In any circuit design, the question must be asked: “What happens if a component fails in the circuit?” Considering the dryer example again, the input is connected to a 240 VAC high voltage source capable of delivering up to 30 A which is very dangerous. Since the X capacitor is directly across the line and neutral, the capacitor is seeing the high AC voltage over the entire lifetime of operation of the dryer. If the X capacitor were to fail, the 240 VAC would now be shorted to neutral which will either blow a fuse or result in a fire. If a Y capacitor were to fail and the ground connection of the dryer were compromised, the 240 VAC would now be on the chassis ground which is connected to the metal enclosure. This would result in a scenario of the metal enclosure being energized by the high AC voltage and risking electric shock to the user. Therefore, it can be assumed that the reliability of X and Y capacitors for AC line filtering are critical to the safety of the user operating the device. The capacitor must be able to not only operate at a constant high AC voltage, it must also survive transient voltage spikes due to lightning surges.