Electrical Systems


  • The relatively new home, or the one with an updated electrical system, will allow for safe and reliable use of the latest electric "toys". But, houses built under older codes often suffer from outdated electrical systems not designed for today's uses.

    These older systems typically have a fuse box with a 60 or 100 amp capacity, and individual circuit wires insulated with ceramic tubes and spindle-like knobs ("tube and knob wiring". These systems were designed primarily to be used for simple lighting circuits. The assumption was that most rooms would have a single overhead light and possibly one floor lamp. Such a wiring system, if well maintained, will continue to serve for its original purpose--namely lighting. But the designer of this system could not envision the proliferation of electric appliances.

    Our microwaves, video recorders and other electronic toys are items that, in combination, can often cause an overload. In addition, the old wiring systems were not designed to accommodate the many portable heaters on the market today.

  • Fire departments list electrical problems as one of the major causes of fires in the home.

    Typically, such a fire starts with the homeowner replacing the original 15 amp fuses with, for example, a 30 amp fuse, in the mistaken belief that a larger fuse is better because it blows less often. The homeowner now has inadvertently destroyed the very system designed to protect the home.

    The danger lies in the overheating of the wire at its weakest link. An example of this can be seen in attaching a new, higher capacity wire to an old tube and knob circuit. If such an installation is over-fused and overloaded, it is possible for the old tube and knob wiring inside the wall or crawl space to overheat and possibly start a fire. The fire can start without blowing the oversized fuse or any other sign of a problem in the new segment of wiring.

    An inspector or qualified electrician may be needed to determine whether a home has an electrical system adequate for today's needs.

  • The electrical system that will accommodate most of today's electric appliances is usually characterized by the following:

    • A single, 125 amp or larger electrical panel with circuit breakers. A label on the inside of the panel will indicate the amperage capacity.
    • Electrical receptacles for three-pronged plugs.
    • Receptacles placed within six feet along wall surfaces.
    • Ground fault circuit interrupters (GFI) protecting receptacles in the bathroom and, in the newest homes, in the kitchen and out-of-doors. The presence of an interrupter may be indicated by the presence of two small test/reset buttons on the three-pronged receptacles.
    • Arc Fault Interrupters (AFIs) are the latest safety device and help prevent electrical fires. The latest electrical codes require their use in bedroom circuits.
    • Wiring neatly done. All connections inside a plastic or metal electrical box. All electrical boxes have a proper cover.

    However, a little knowledge can be dangerous: just because the receptacle is of the newer 3 pronged variety does not mean that it was wired correctly, the same can be true about the GFIs and AFIs.

    • Larger fuse sizes used to "prevent fuses from blowing." Note: It is probable that 30 amp fuses or larger are the proper size for the water heater, dryer and stove, but not for other circuits.
    • 15 or 20 amp fuses blow regularly.
    • Extension cords used as a permanent part of the system.
    • Lights dim when an electric appliance is turned on.
    • Use of adapters to increase the number of appliances plugged into one receptacle.
    • Use of converter plugs to allow appliances with three-pronged plugs to be plugged into two-pronged receptacles.
    • Three or more electrical panels in a single family home.
    • Messy wiring practices.

  • Most older home electrical systems can be upgraded into safe and fully functional systems without a complete re-wiring of the home. Some of the original wiring - even some of the old "tube and knob" - may be safely used for lighting circuits and other low amperage utility circuits. The "87 gig drive" needs a newer grounded circuit, but the light and table radio next to the computer will work fine in a properly functioning 1910 circuit.

    So, if you get a bid from an electrician for a re-wiring of the house, here are a few questions to ask:

    • Could the existing electrical entrance provide me with enough amperage if I switched some of the larger appliances to natural gas or propane? (Note: a larger home may not need more than a 100 amp. entrance if most of the cooking, heating, water heating and clothes drying is done with gas or propane).
    • Conversely, does this work take into account next years project? For example, a new kitchen may require further upgrades to the electrical capacity of the entrance.
    • Can some of the existing circuits be used in conjunction with some new circuits?
    • If some of the new wiring is being performed during a remodel, would this be a good time to add new circuits to neighboring rooms?
    • Are some of the proposed upgrades required in new construction but not required in existing older homes? And, if not, do I need them? For example, today's code requires a receptacle within 6 feet of any wall surface. But that code does not apply to most existing walls in an older home. Adding receptacles in some walls may be very useful in some areas but not in others.
    • Will the electrical work damage any surfaces, trim or other elements of the home? Is the restoration included in the bid? (Note: electricians who specialize in remodeling and upgrades may be able to perform the work with less damage to the home).
    • Does the bid include permit (and any hookup) costs?
    • Which fixtures (if any) are included in the bid?
    • What about additional telephone and cable wiring?
    • Is this a good time to add a new bath fan or ducted kitchen fan? (George's Tip: Some of the newer bathroom fans are very quiet, pick one with a "sone" rating of 1.5 or less. Quiet fans are used more often, and more frequent fan usage reduces moisture damage and mildew).

    A note about electricians and other specialty contractors: Some electricians, as well as some roofers, plumbers etc., suffer from the "specialist disease". They are expert in their area of work, but may not be thinking about related items and issues. For example, how to reduce electrical capacity requirements by using natural gas, or how to reduce the need and frequency of bathroom re-painting by installing a better quality fan.

    • When purchasing an extension cord, select a cord which is rated for the desired use, for example, a desk lamp, a 13 amp portable saw or a computer.
    • Make sure that the extension cord is plugged into a properly wired receptacle.
    • Utility extension cords plugged into a ground fault interrupter receptacle for yard or power tools should follow the guide on the extension cord package.
    • One standard, indoor-use extension cord to connect a table or floor lamp to a receptacle.
    • Temporary use according to instructions; for example, Christmas tree lights.
    • Always use the shortest extension cord possible.

    • Never connect an extension cord to the house or furniture with tape, staples or nails.
    • Never cover an extension cord with carpet, pillows, or other material.
    • Never connect one extension cord to another unless you know how to calculate electrical loads.
    • Never use extension cords to "solve" the shortcomings of a house with one or two receptacles per room.
    • Never use a long cord before uncoiling it.

  • Bathroom accessories; i.e., electric toothbrush, hair dryer, electric shaver: Use a circuit protected with a Ground Fault Interrupter (GFI). Note: Most standard bathroom circuits are designed for hair dryers using no more than 1000 watts. Check the label on your hair dryer, it may be too strong for a "normal" bathroom circuit.

    Microwave ovens: A separate 20 amp "dedicated" circuit on its own fuse or circuit breaker.

    Dishwasher: Needs a separate 20 amp "dedicated" circuit.

    Larger vacuum cleaners and irons: Plug directly into a 20 amp receptacle--usually found in kitchen and utility rooms.

    TV, stereo, VCR, audio tape system: Check the wattage rating on each unit and limit load to 500 watts on a single room circuit. Add a separate circuit if necessary.

    Electric blankets: Plug directly into an adequate receptacle with a 15 or 20 amp fuse or circuit breaker.

    Personal computer system: A separate "dedicated" circuit on its own fuse or circuit breaker.

    Portable electric space heater: Plug directly into a 3-pronged, grounded receptacle with a 15 or 20 amp fuse or circuit breaker. (1000 watt limit on any 15 amp circuit. 1500 watt limit on any 20 amp circuit.)

    Outdoor equipment: Ground fault interrupter (GFI).

    Home workshop tools: Purchase "double insulated" power tools.

    Portable hot tub or spa: Needs a "dedicated" circuit with a GFI circuit breaker. Requires a 125 amp, or larger, electrical panel.

    Kiln or arc welder: 220 volt circuit which may require a 200 amp, or larger, electrical panel.

  • Many homeowners like to do their own electrical work. Unfortunately, much of the electrical work done by nonprofessionals does not meet the electrical code and is dangerous. Poorly installed panels and wiring can cause home fires.

    The homeowner who decides to do his or her own electrical work should keep in mind the following guidelines:

    • An unlicensed electrician may only work on his or her own residence.
    • Most modifications to electrical systems require an electrical permit. Permits may be obtained from your local building department, or from the state Department of Labor and Industries.
    • The home electrical system is the most complex and potentially dangerous system in the home. The untrained individual is best advised to hire a licensed electrician.
    • However, if you decide to do your own electrical work, there are good books and manuals from the Sound Home Bookstore that explain the current electrical code and techniques for residential wiring.