ADS is one of several different methods of providing some protection against electric shock under fault conditions, and works by limiting the duration of the shock current. ADS considers metallic parts that would normally be safe to touch but would made hazardous live by a failure of basic insulation - for example the metal cases of electrical equipment. These parts are normally connected to Earth and also the source of the supply is also connected to Earth - such that if a fault does make that part live then a short-circuit is created and protective devices can then detect the short circuit and automatically disconnect the circuit - so removing the hazard. Depending on the details of the Earthing arrangement the protective device might be a simple fuse or a circuit breaker, or might need to be a residual current device.
ADS is one of several different methods of providing some protection against electric shock under fault conditions, and works by limiting the duration of the shock current. ADS considers metallic parts that would normally be safe to touch but would made hazardous live by a failure of basic insulation - for example the metal cases of electrical equipment. These parts are normally connected to Earth and also the source of the supply is also connected to Earth - such that if a fault does make that part live then a short-circuit is created and protective devices can then detect the short circuit and automatically disconnect the circuit - so removing the hazard. Depending on the details of the Earthing arrangement the protective device might be a simple fuse or a circuit breaker, or might need to be a residual current device.
