This situation violates Section 410-58(d). Grounding type attachment plugs and mating cord connectors and receptacles must be designed so that the grounding connection is made before the current-carrying connections. The pin in the plug was removed, which is a typical scenario on many construction sites. There are many reports of lives lost because of this situation, and this condition also brings a heavy fine by enforcing authorities. Also, understand that grounding-type attachment plugs should be used only with a cord having an equipment grounding conductor. See Section 410-58(e).
Section 250-114 requires that exposed noncurrent-carrying metal parts of cord and plug connected equipment likely to become energized must be grounded, unless they are protected by a system of “double insulation” or its equivalent. Double-insulated equipment shall be distinctively marked. Double insulation protects the user against electric shock by creating a non-conducting barrier between the operator and the electric components inside the tool.
