Shingles is the reactivation of a viral infection in the nerves to the skin that causes pain, burning, or a tingling sensation, along with an itch and blisters in the skin supplied by the affected nerve. It is caused by the varicella zoster virus[1] , or VZVâthe same virus that causes chickenpox.
Types of electrical circuits. There are three main types of circuits encountered in a domestic situation. They are ring circuits, radial circuits and lighting circuits.
Class 2 and 3 Circuits. Class 2 and 3 circuits are defined as the portion of the wiring system between the power source and the connected equipment. Because of the power limitations of Class 2 circuits, many consider them to be safe from a fire initiation standpoint and to provide an acceptable level of protection from electrical shock.