There is a wide range of electric shower heads, with various designs and types of heating controls. The
heating element of an electric shower is immersed in the water stream, using an often replaceable
nichrome resistive heating element which is often not sheathed and electrically isolated, in which case isolation is provided by earthing electrodes that directly touch the water before it exits the head. Electric shower heads with sheathed and electrically isolated heating elements are often marketed as such (
chuveiros blindados in Portuguese) and are more expensive. Due to electrical safety standards as well as cost, modern electric showers are made of plastic instead of using metallic casings like in the past. As an electrical appliance that uses more
electric current than a clothes washer or a hair dryer, an electric shower installation requires careful planning, and generally is intended to be wired directly from the electrical distribution box with a dedicated
circuit breaker and ground system. A poorly installed system with old aluminum wires, bad connections or an unconnected ground wire (which is often the case) may be dangerous, as the wires can overheat or electric current may leak via the water stream through the body of the user to earth. ==References==