When mains filters are used in the power circuits supplying an electrical or electronic assembly, e.g., a variable frequency drive or an AC-DC power converter, leakage currents will flow through the "Y" capacitors that are connected between the live and neutral conductors to the earthing or grounding conductor. The current that flows through these capacitors is due to the capacitors' impedance at power line frequencies.[6][7] Some amount of leakage current is generally considered acceptable, however, excessive leakage current, exceeding 30 mA, can create a hazard for users of the equipment. In some applications, e.g., medical devices with patient contact, the acceptable amount of leakage current can be quite low, less than 10 mA.