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Flexible wiring can be used for extension cords or power supply cords. Power supply cords can be removable or permanently attached to the appliance.

flexible wiring—cables with insulated and stranded wire that bends easily

A 29-year-old male welder was assigned to work on an outdoor concrete platform attached to the main factory building. He wheeled a portable arc welder onto the platform. Since there was not an electrical outlet nearb , he used an extension cord to plug in the welder. The male end of the cord had four prongs, and the female end was spring-loaded. The worker plugged the male end of the cord into the outlet. He then plugged the portable welder s power cord into the female end of the exten- sion cord. At that instant, the metal case around the power cord plug became energized, electrocuting the worker.

An investigation showed that the female end of the extension cord was broken. The spring, cover plate, and part of the casing were missing from the face of the female connector. Also, the grounding prong on the welder s power cord plug was so severely bent that it slipped outside of the connection. Therefore, the arc welder was not grounded. Normall , it would have been impossible to insert the plug incorrectly. But, since the cord s female end was damaged, the “bad” connection was able to occur.

Do not let this happen to you. Use these safe practices:

  • Thoroughly inspect all electrical equipment before beginning work.

  • Do not use extension cords as a substitute for fixed wiring. In this case, a weatherproof receptacle should have been installed on the platform.

  • Use connectors that are designed to stand up to the abuse of the job. Connectors designed for light-duty use should not be used in an industrial environment.

DO NOT use flexible wiring in situations where frequent inspection would be difficult, where damage would be likely, or where long- term electrical supply is needed. Flexible cords cannot be used as a substitute for the fixed wiring of a structure. Flexible cords must not be . . .

Don’t use flexible wiring where it may get damaged.

run through holes in walls, ceilings, or floors;

run through doorways, windows, or similar openings (unless physically protected);

attached to building surfaces (except with a tension take-up device within 6 feet of the supply end);

hidden in walls, ceilings, or floors; or

hidden in conduit or other raceways.

Section 7

Page 43

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