DIY Electrical repairs:
Q. I was changing the light switch in my bedroom to a dimmer switch and got quite a shock. I had turned off all the power to the bedroom and I even checked the outlets to make sure the power was off. When I removed the switch and touched one of the wires I received a shock. How is that possible when the power is turned off?
A. I strongly discourage any do-it-yourself electrical repairs, because the outcome can be fatal. One small mistake and you could be electrocuted and/or cause a fire.
If you must do electrical repairs, make sure all the circuits are off at the main breaker or at the fuse disconnect. Once the work is completed, have the repairs inspected by a municipal inspector or a licensed electrician before restoring the power.
Here’s a simple explanation of what may have happened.
The lighting circuits and bedroom outlets in the room where you were working are probably all on one circuit. A modern home uses Romex wiring where the black (positive) wire is used to feed power to the light or outlet and the white wire is used as the neutral. If you have an older home, you will find that the wiring is not color-coded and you would need the assistance of an electrician to make proper and safe connections.
If, at some point in the home, the feeder wire and neutral wire are reversed at a switch or outlet connection, the current can feed back to the neutral side of the electric panel to the wire you are touching. This is because all the neutral wires are connected to the same neutral buss bar inside the panel and they can become energized if there is a reversed polarity problem anywhere in the house.
Reversed polarity is quite dangerous and needs to be corrected. At switches and outlets, the neutral wire is connected to the silver screw and the feeder wire connects to the brass-colored screw. Modern outlets will even be marked for the white-wire connection. The green screw is for the bare or green grounding wire in the cable.
You can check outlets for reversed polarity by purchasing a plug-in polarity/grounding outlet tester. A simple tester retails for less than $12 and is available at home and hardware stores. If all the outlets check out as being wired correctly, then hire an electrician to inspect the wiring connections at the light fixtures and lighting switches where the black wire, not the white wire, is supposed to be switched.
Q. What is Romex wire? The person who inspected the house I’m selling will not return my calls to explain where the wires are located and why they have to be protected.
A. A professional home inspector cannot release information to you, to the selling agents or to anyone without the permission of the person who hired him.
The ethics code for the American Society of Home Inspectors (ASHI) states: “Inspectors shall not disclose inspection results or client information without client approval. Inspectors, at their discretion, may disclose observed immediate safety hazards to occupants exposed to such hazards, when feasible.”
This may be one reason your phone calls have not been returned. However, common courtesy would require the inspector to make some contact just to let you know why he cannot reveal information. If the wiring is dangerous, the inspector has an obligation to inform you.
Romex wire is a brand name commonly referred to in the trade as “nonmetallic sheathed cable,” typically found in residential construction. Romex consists of three separate wires all protected by an outer layer of insulating materials. Of these three inner wires, two are also insulated and one is an uninsulated or bare copper wire.
I understand that when the insulated Romex wire is installed in a location easily accessible by humans, it should be protected against accidental impact or contact. If the outer layer of insulation is accidentally damaged and one of the two insulated wires also is damaged, you would be exposed to a possible electrical shock.
I often see Romex wiring in good condition but exposed under kitchen sinks for a garbage disposal, or the wiring is exposed from the service box to an electric water heater.
In either instance, the Romex wire’s outer protective insulation could be damaged by accidental impact, which could expose the 120-volt wires to human contact. Such contact can cause a serious shock or even death, making the wiring’s protection extremely important.
Changing cover plates and lightbulbs is easy enough for anyone to do. But a handy homeowner can also take on other electrical tasks with just a few precautions. However, there are other tasks that should be left to professionals. Before you begin, always turn off the breaker that serves the circuit on which you are working. If in doubt, turn off the whole house with the main circuit breaker.
DO: Change a Light Fixture
New, updated light fixtures spruce up an outdated room. Changing them is as simple as disconnecting the old fixture and reconnecting the wires to the new one. An assistant that helps hold a heavy light fixture in place is a welcome addition.
DO: Replace an Old Receptacle
As receptacles wear out, they can loosen. Eventually they will be unable to hold a plug, and you will need to replace them.
DO: Change a Switch or Install a Dimmer
Flickering lights can mean an old, worn-out light switch. You can replace a worn one, or change out a standard switch for a dimmer.
DO: Change an Existing Ceiling Fan
Ceiling fan boxes need to be securely fastened into ceiling joists. An experienced homeowner can do this, but if you’re new at it, stick to replacing an existing fan only. Hire an electrician to install a new one.
DON’T: Alter Wiring in the Walls
Hire an electrician to trace out your circuits and repair, replace or install wiring that will be covered by walls. If you do your own wiring, have a certified electrician inspect it before you cover it with drywall.
DON’T: Install Hard-Wired Appliances
Leave it to an electrician to install ranges, dishwashers and other appliances that cannot simply be plugged in to an outlet. Loose or improperly made connections create fire hazards and are a common cause of household fires. These special appliances often require 220 voltage outlets as opposed to the standard 110 voltage service to the rest of the house. They also require higher capacity circuit breakers.
DON’T: Replace a Circuit Breaker
Working in your electrical panel poses a shock hazard and should always be left to an experienced electrician unless you are handy with electrical circuits and you have a basic understanding of the wiring process.
DON’T: Splice Between Junction Boxes
Never splice wires between junction boxes. This is the first safety precaution most budding electricians learn because it may result in a fire within a wall. A single length of wire should run from outlet to outlet or from outlet to switch or from switch to light fixtur