The invention relates to earth connections to workpieces particularly a workpiece to which an arc is to be struck, and more particularly to a workpiece that is underwater. It is of considerable importance that a workpiece is properly connected to earth, and that the impedance of the connection is not such as will elevate dangerously the voltage on the workpiece. The objective of the invention is to solve this problem, an objective met by an earth connection for workplaces that comprises a loop in the connection of the workpiece to earth, the loop being connected at each end to and being completed by the workpiece, and there being a sensor means to sense current flowing in the loop above a predetermined level.