Why an electric shock from a 240v supply can kill you but an 3000v DC supply from a static charge should not while walking across a nylon carpet and touching a metal door knock?

can dc volts kill you? It is in relationship to the amount of time the body is conducting the milliamp current. With your DC static charge, once the potential voltage has equalized by grounding the current flow stops. On a 240 volt system the voltage remains constant thereby causing the current to continually flow through the body. If you have ever has an electrical shock you know the feeling.