The AC safety ground is the third pin on your plug that should be attached to the chassis of your washer/dryer on one end, and somehow connected to the neutral wire somewhere near your breaker box. You may well find that the wiring codes in your country mean you already have a residual current circuit breaker in place. An emergency isolation switch. Santeri Viinamäki [CC BY 3.0], via Wikimedia .
rcbo wiring diagram Image Schematics