Electrical Plug Detective

Problem: Plug sparks when used, does not carry power to lamp or appliance, or causes short circuits.

Background: There are eight or more different kinds of receptacle plug configurations, but they all fall within two major categories: flat wire plugs and round cord plugs. Replacement plugs are readily available for both kinds and may be found in two basic types: replacement plugs, which use screws to connect cord wires to the terminals, and quick-connect plugs, which have spikes inside that make contact with the wires. Plugs should be re placed whenever the casing is cracked or damaged, the prongs have be come loose or badly bent, the insulation faceplate is gone, or the cord near the plug has become damaged.

What to do: Clip off the old plug and take it with you when buying a re placement. When using a quick- connect flat wire replacement plug, read the general directions below, then proceed by following the manufacturer’s instructions, if any are given. For replacing the appliance-end plug, or appliance cord.

Flat wire plugs: With take-apart replacement plugs, the casing has a screw which allows the casing to be taken apart in two halves, freeing each prong which has a screw terminal. Re move about ½-inch of insulation from the wires, twist them and hook each wire around a terminal and tighten. Reassemble the casing and install the insulation cover.
Procedures vary in attaching a quick-connect replacement plug because there are at least three different kinds. One kind has a levered clamp at the back which is pulled up, the wire (slitted ¼ inch between strands) is pushed into a hole at the side, and the clamp is pushed back into the casing. With a second kind, the prongs are squeezed together so that the interior can be pulled out. The prongs are spread the wire inserted, the prongs are closed, and the interior part is pushed back into the casing. A third kind has a wrap-around casing which slips off, then the wire is simply inserted and the casing is slipped back on.
Round cord plugs: These will have screws to attach wires. Cut the damaged part of the cord off, then slip the plug onto the cord. Clip and separate the cord and tie what is called an underwriter’s knot (see illustration) and pull knot back into plug snugly. Remove ½ inch of the insulation from the ends of the wires, and twist the strands of each wire together clockwise. Wrap the end of the black wire around under the brass screw, wrap the end of the white wire around under the silver screw (insulation should not come under the screws), and tighten screws.
If the cord has solid wires, pre bend the ends clockwise with needle-nose pliers to fit under screw terminals. On a 3-prong plug there will be a third green wire which is attached to the ground screw terminal. Placing the insulation cover back on plug, and tightening any cord clamp, completes the replacement.

Special advice: Plug prongs some times don’t fit the receptacle properly. If not, try spreading the prongs of the plug to fit tighter into the receptacle. To pre vent damage to electrical plugs, make it a habit to always remove a plug from a receptacle by grasping the plug, not the cord. Pulling only the cord will cause unnecessary wear and premature failure of the plug.

Helpful hint: A wire stripping tool is a low-cost, pliers-like device which makes stripping insulation from wires more precise. Most have holes to accommodate wires in a range from 20- to 10-gauge. You simply select the proper hole, position the wire where you want the insulation to end, then squeeze the handles and pull. It is a worthwhile investment.

Electrical Circuit Fails

Problem: Fuses blow or circuit breakers trip because of problems at the main panel.

Background: Circuit breakers and fuses act as the first line of defence when an electrical failure occurs. When a fuse blows or a circuit breaker trips, it indicates that some thing is wrong within the circuit. Re placing the fuse or resetting the circuit breaker should not be done until the cause is determined. Ignoring this condition could cause a fire hazard, draw excessive power and run up your electric bill, or make appliances run below optimum levels, which could possibly damage motors and compressors.

What to do: Check for problems caused by short circuits, and for problems caused by overloaded circuits. Check below for circuit failures that are caused at the main panel. Do not work on a fused or breaker panel unless you are familiar with electrical safety procedures and are confident of your abilities.

Loose connection in a fused panel: After turning off the power, remove the fuses. (Warning: The connections where the main wires enter the panel are hot.) A loose screw may be found in one of the fuse sockets. If the bottom of the fuse is blackened, discolored, or pitted, a loose connection may be at fault.
Loose connection in a circuit breaker panel: After turning power off, remove cover from panel. Inspect the panel for darkened or pitted marks on the bus (the strip of metal where a number of connections are made on the panel) or circuit breakers. Also check the wires connected to the circuit breakers for signs of excessive heat.
Fuse poorly seated: Although the fuse window shows no indication of burn out, and the bottom is not pitted or discolored, the fuse may not be making contact with the bottom of the receptacle. Remove the fuse and replace it with one of adequate length to make contact.
Special advice: If any of the above conditions exist, contact an electrician. If there is an unused branch space in the existing panel, it may be possible to move the branch wire from the damaged fuse or circuit breaker to the unused space and in stall a new fuse or circuit breaker. If there are no unused spaces, the en tire panel may need to be replaced. If so, consider having the electrician install a larger service to meet future electrical needs more adequately.

Helpful hint: To avoid overloaded circuits, never insert a fuse in a panel that has a higher amperage rating than the rating on the wire for the circuit. Never use a penny or tin foil in a service panel instead of a fuse.