Common Electrical Questions & Answers
- If you have an old house with old wiring how do you know if repairs are necessary? How extensive and costly can such repairs be?
- How does a three-prong plug work? What’s the benefit of using it?
- How does a polarized plug work? What’s the benefit of using it?
- What is a GFCI?
- How does the GFCI work?
- If the GFCI is working, is there any danger of electric shock?
- Do all GFCIs work in the same manner?
- If an appliance has a built-in shock protector, is an additional GFCI necessary?
- Can consumers install GFCIs?
- What is the big plug now found on such appliances as hair dryers?
- If the product has a three-prong grounding type plug, is a GFCI still necessary?
- What size extension cords should a consumer use? How can you tell if an extension cord is appropriate for the intended use?
- Are there any benefits to using circuit breakers instead of fuses?
If you have an old house with old wiring how do you know if repairs are necessary? How extensive and costly can such repairs be?
Electrical systems age and can become overloaded, particularly in older homes. Over the years as more lighting, appliances and equipment are added, the electrical system becomes overburdened and problems can develop. If fuses blow or circuit breakers protecting branch circuits trip frequently, new branch circuits or other repairs may be necessary. Depending on the condition of the equipment and the extent of the repairs, the cost may be nominal or could run into several thousand dollars. A qualified licensed electrician can determine if repairs are necessary and can estimate the cost.
The third prong on a three-prong cord set provides a ground path to your circuit breaker or fuses that can detect if electricity is straying or leaking from a product. This helps protect equipment and can help prevent electric shock.
A polarized plug is a plug with one large or wide prong and one narrow one. It ensures that the plug is inserted correctly in a socket and reduces the risk of electrical shock.
A Ground Fault Circuit Interrupter or GFCI, is an electronic device for protecting people from serious injury due to electric shock. They are often found on bathroom or kitchen circuits, or other circuits located close to water.
GFCIs constantly monitor electricity flowing in a circuit. If the electricity flowing into the circuit differs by even a slight amount from that returning, the GFCI will quickly shut off the current flowing through that circuit. The advantage of using GFCIs is that they can detect even small variations in the amount of leakage current, even amounts too small to activate a fuse or circuit breaker. GFCIs work quickly, so they can help protect consumers from severe electric shocks and electrocution.
Even if the GFCI is working properly, people can still be shocked. However, the GFCI can act quickly to prevent electrocution.
All GFCIs work in the same manner to protect people against ground faults. However, unlike the receptacle GFCI, the circuit breaker type GFCI also provides overload protection for the electrical branch circuit.
Appliances that have built-in shock protectors, as now required for hair dryers, may not need additional GFCI protection. However, other unprotected appliances still need GFCI protection.
Consumers are encouraged to use a qualified and certified electrician to install circuit breaker-type GFCIs. Individuals with strong knowledge of electrical wiring practices, who can follow the instructions accompanying the device, may be able to install receptacle-type GFCIs. The portable GFCI requires no special knowledge or equipment to install.
The large box-like device found on the ends of some appliance cords can be either an appliance leakage circuit interrupter (ALCI), an immersion detection circuit interrupter (IDCI) or a ground fault circuit interrupter (GFCI). They work in different ways, but they are all intended to shut off the power to an appliance under an abnormal condition such as immersion of the appliance in liquid. Just because you have an appliance with one of these devices, it doesn’t mean that it is okay to drop the appliance in water and retrieve it while it’s plugged in. If you should happen to drop an electrical appliance in in water, shut off power to the circuit into which the appliance is plugged, unplug the appliance, drain the water and retrieve the appliance. The rule that “electricity and water don’t mix” still applies.
GFCIs are necessary even if the product has a third wire to ground it. GFCIs provide very sensitive protection to consumers against electric shock hazards. Under some conditions, a shock hazard could still exist even if a product has a grounding wire.
What size extension cords should a consumer use? How can you tell if an extension cord is appropriate for the intended use?
Before purchasing an extension cord, consumers should consider how the cord will be used. Make sure the rating on the cord is the same as or higher than the number of watts needed by the product that will be plugged into the cord. Extension cords should never be used as a substitute for permanent wiring.
The main difference between circuit breakers and fuses is that circuit breakers can be reset while fuses operate only once and then must be replaced. If your breakers or fuses trip repeatedly, call an electrician because you may have a problem with your electrical system.