How to Hook Up a Male Electrical Plug
The male power plug is, for many electrical devices, the component that fails first, long before the appliance is no longer serviceable. The plug is the part of a lamp or appliance that often receives the most physical stress, causing it to separate or crack, or the wires to loosen or become damaged. By replacing the power plug, you may gain years of service from a previously nonfunctional device. Does this Spark an idea?
Other People Are Reading
Things You'll Need
- Replacement plug
- Wire cutter
- Wire stripper
- Utility knife
- Needle nose pliers
- Screwdriver
- Ohmmeter (optional)
Instructions
-
-
1
Inspect the lamp or appliance, and the power cord. Make sure there are no other cracks or splits in the cord, and that there is no bare copper wire showing. If there is, you will need to replace the entire power cord.
-
2
Purchase a replacement plug at a hardware store. The new plug must have the same number of prongs as the existing plug (either two or three). The new plug must also have the same power capacity as the appliance or lamp to which it is connected.
Examine the appliance--there is usually a plate somewhere that will list the wattage and amperage that the appliance requires. Choose a plug that is rated for this amperage or greater.
For table lamps, any commercially available plug will suffice.
If the appliance is such that its cord is often yanked to unplug it from a distance, consider a plug that has an external clamp to hold the plug to the cord. This will prevent the wiring from coming loose when the cord is yanked.
-
-
3
The wire nearest the existing plug may be damaged, so cut approximately 4 inches of wire and the plug off the existing cord.
-
4
If there is an outer insulation cover on the wires (like some vacuum cleaner cords), expose the individual conductors by cutting the insulation lengthwise with a utility knife.The distance will be governed by the configuration of the replacement plug, but in general, you do not want any individual conductor wires exposed at the rear of the replacement plug.
If the wire is two conductors with molded insulation (a typical lamp cord), separate these by pulling them apart. The length of wire you need to separate is governed by configuration of the replacement plug. In general, you do not want separated conductors visible at the rear of the replacement plug.
-
5
Strip approximately 1 inch of insulation from each of the conductors.
-
6
Feed the cord through the housing (back end) of the new power plug.
If there is no external cord clamp, and there is sufficient room inside of the housing, tie an underwriters knot in the cord to relieve tension caused by someone pulling on the cord.
-
7
If this is a three-prong plug, connect the ground wire to the ground terminal. The ground wire will either be bare copper or have green insulation. The ground terminal is the center prong, and the screw terminal will often be green.
With your needle nose pliers, wrap the uninsulated section of the wire clockwise around the screw and tighten the screw. There should be no bare copper wire visible, and no insulation trapped under the screw.
-
8
Identify the neutral wire coming from the lamp or appliance. The neutral wire will be silver, or will have ridges on the insulation, or if there are separate conductors inside an outer insulation, it will be the white wire.
Connect the neutral wire to the neutral screw terminal on the plug. This will be the wider prong, and will often be marked by a silver screw.
With your needle nose pliers, wrap the uninsulated section of the wire clockwise around the screw and tighten the screw. There should be no bare copper wire visible, and no insulation trapped under the screw.
-
9
The remaining wire is the hot wire. It will be gold, have unmarked insulation, or if there are separate conductors inside an outer insulation, it will be the black wire.
Connect the hot wire to the hot prong. This will be the narrow prong, and will often be marked by a gold screw.
With your needle nose pliers, wrap the uninsulated section of the wire clockwise around the screw and tighten the screw. There should be no bare copper wire visible, and no insulation trapped under the screw.
-
10
Assemble the plug housing and tighten as necessary.
-
1
Tips & Warnings
If the neutral wire is not clearly marked, you may use an ohmmeter (or the ohmmeter section on a multimeter) to determine its location. For a lamp, touch one lead of the ohmmeter to the outside of the bulb socket and the other lead to the bare end of one of the wires. When you have a reading of zero ohms, that is the neutral wire.
Some small capacity plugs may not have screw terminals, but instead rely on small metal pincers, which pierce the insulation when the plug is assembled. For these plugs, do not strip the insulation from the wires before inserting into the plug.
Mixing up the hot and neutral wires greatly increases the risk for electrical shock from a lamp or appliance, even though the appliance will still be functional.
