Detecting Residual Currents at Mixed Frequencies
Type F RCDs
Type F RCDs are designed to provide protection against residual fault currents comprising of composite frequencies e.g, 10 Hertz + 50 Hertz + 1000 Hertz.
Installations where multi- frequency components can exist, e.g. inverters and motor control systems, residual currents at mixed frequencies can occur under fault conditions and cannot be detected by Type A RCDs. Type F RCDs provide the ideal protection device in such installations.
An additional advantage of Type F RCDs is that they have a higher level of immunity to surge currents than Type A RCDs and therefore are less prone to nuisance tripping due to lightning surges etc.
WA offers Type F RCD solutions in the form of technology that OEMs can integrate into their products compliant to IEC/EN 61008 and IEC/EN 62423.