Install grounding cords on motor-operated and "wet" appliances for safety
 
To take the shock hazard out of any metal-body electrical appliance, you have to do only two simple revamping jobs: 1) Add a grounding wire to the present cord and replace the present two-prong non-polarized plug by a three-prong polarized plug; 2) Replace existing two-prong outlets by three-prong receptacles to take the new plug, or use polarized adapters.

Actually, the easiest way to add the life-saving third wire is to use a length of new three-wire cord. In this the ground lead is colored green, and the current-carrying wires are black and white. Electrical and hardware stores now carry such cords in various lengths, with a polarized plug already molded permanently to one end. If you prefer, you can buy the cord and the plug separately.

Portable drills, saws and other motor-operated tools are prime customers for three-wire safety cords.  Old  cord is  probably  torn, so cut  it off.

With handle removed or case opened, two leads from motor are located, pulled out carefully and cleaned off. Colors are usually black and white.

Grounding prong on a polarized plug is the long round one, represented at other end by a green wire. Run a continuity check with volt-ohmmeter.
 
Pull end of new three-wire cord through hole in body of tool and solder black to black, white to white. To green wire solder lug that fits screw.

With your portable drill fitted with a three-wire cord, you can work in perfect safety even on a damp garage or cellar floor without danger of shock. In case of internal short-circuit, you only blow fuse.

After you tape the black and white splices, it is time to reassemble handle. Slip the ground lug over one screw and be sure to tighten well.
 
In order to take possible strain off your cord, as well as to increase its life, tape and then tie it securely to the under side of hand grip.

Make your own safety cord: Pull wire through polarized plug, trim off covering and insulation; clean and tin lightly to keep from coming apart.

Screwdriver points to green-colored terminal of ground prong of polarized plug. White lead must go to light prong and black lead to brass prong.
 
Old outlets in house or shop should be replaced by new polarized type to accommodate safety plug (left). However, satisfactory expedient. 75% safe, is in form of adapter.

For semipermanent use with a particular outlet, ground wire of polarized adapter can be fastened under mounting screw of receptacle cover plate, provided the box is grounded.

Polarized receptacle and a polarized plug with three-wire cord mean complete assurance against power-line leakage when wet appliances are used.

Study the accompanying pictures for practical how-to-do-it information on this important application of electricity. ·

This is a "crowfoot" plug with matching outlet, also used for voltages higher than 115. Bottom (vertical)  prong   is   used  as   ground  connection.

Screwdriver points to the green-colored ground screw of polarized outlet. Bare ground lead of non-metallic sheathed cable is shown connected.

The new polarized outlets look very much like the old ones except that they have three openings and three terminal screws. The one painted green is the ground connection. If metal outlet boxes are used with flexible armored cable ("BX") or rigid conduit, the ground connection to the green terminal is made automatically when an outlet is mounted, as this terminal is physically part of the mounting ears of the outlet. If non-metallic cable is used, the bare ground wire woven between the insulated wires must be connected to the green screw. Replacing an old outlet is a screwdriver operation that takes a few minutes. Remember, of course, to pull the fuses first!

Pencil points to special tandem-blade polarized plug for 208/230-volt machines. Blades are in line  but  standard  polarized  plug's  are parallel.

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