HOME SAFETY : Electrical Tools Used Outside Need Grounding

Your best guarantee of safety while using electrical tools outside or in damp areas is to be sure that everything you use is plugged into a ground fault circuit interrupter. This electrical device instantly detects a hazardous situation and cuts the flow of power before a fatal shock is delivered.

Current electrical codes require outside outlets and those in the bathroom and kitchen or in damp areas be protected by this device. New homes must have it, but homes those built before 1974 have only grounded circuits with a circuit breaker or fuse protector. Neither is as safe as circuit interrupter protection in conjunction with a fuse or circuit breaker.

Also, double-insulated tools and tools with a heavy-duty, three-wire grounded cord offer good protection against shock, but their safety feature can be interrupted by accident or improper use.

Circuit interrupters are inexpensive and easy to install. It’s a simple to add one to a three-wire cord. To do this, you replace the receptacle end of the cord with a circuit interrupter receptacle housed in a weatherproof box.

A circuit interrupter current (amps) flowing to and from electric tools and equipment. Under normal operating conditions, the current flowing to the tools is the same as that returning to the electrical panel. When a ground fault occurs, some of the current is diverted to the ground by a short somewhere in the circuit. If the short is through you to the ground, you are in for a shocking experience.

The device senses current-flow imbalance--as little as 5 milliamps (which can’t hurt most people) and shuts off current flow in a fraction of a second.

It can be added to a metal or plastic box. Metal exterior boxes come threaded for box connectors. Plastic boxes may be threaded, but many brands require an adapter. If you plan to use a plastic box, get the necessary plastic parts so the box can accept a standard clamp-type box connector.

Aside from the ground fault circuit interrupter receptacle, you need the following materials and tools: a 25-foot 14-2 extension cord (14-gauge wire, 2 wires with ground), a weatherproof rectangular outdoor box that accepts dual receptacles, a combination wire cutter and stripper, locking pliers and a screwdriver.

To make the extension cord, cut off the cord’s receptacle and strip about one-half inch of insulation from the ends of the wires. Screw the connector into the end of the box and tighten with locking pliers.

Loosen the clamp on the box connector and pull about a foot of extension cord into the box; connect the wires to the terminals. If you use a metal box, you have to ground it. To do this, run a short section of wire from the green screw on the circuit-interrupter receptacle to the ground screw inside the box. Use wire connectors to join the conductors to the receptacle if it is equipped with wire leads instead of terminal screws.

Pull the excess cord out of the box to make room for the receptacle. Make sure none of the cord’s bare or insulated conductors is exposed outside the box. Tighten the screws on the box connector to clamp the cord in place and install the cover.