Proper grounding of your electrical system is essential to your safety. Electricity always follows the path of least resistance, and that path could be you whenever an appliance or another electrical component is not grounded. Read on to learn more about how electrical grounding works and how to keep your home safe and illuminated.
What is electrical grounding?
Grounding directs electrical energy into the earth by providing a conductor that is less resistant than you are. This is accomplished by attaching one end of the wire to the frame of an appliance and fastening the other end to a cold water pipe. Most plastic-coated electrical cable contains a bare wire, which carries the grounded connection to every electrical box, receptacle, and appliance in your home. You can usually tell whether your electrical system is grounded by checking the receptacles. If you have the kind that accepts plugs with two blades and one prong, your system should have three wires, one of which is a grounding wire. The prong carries the safety ground to the metal frame of any appliance with a three-wire plug and cord.
Safety Hazards of Improper Grounding
An appliance’s metal frame can pose a safety hazard to you and your family. If a power cord’s insulation wears away just at the point where the cord enters the metal frame, contact between the metal current conductor and the metal frame could make the whole appliance alive with electricity. Touching a charged metal frame of the appliance while simultaneously touching a water faucet or a radiator will make the current surge through you.
Other places throughout the electrical system exist where conductor/metal contact is a distinct possibility and a safety hazard. Inspect, maintain, and make repairs wherever wires enter a metal pipe (conduit), where the cord enters a lamp or lamp socket, and where the in-wall cable enters an electrical box. Surfaces at these points must be free of burrs that could chafe the wire and damage its insulation. Washers and grommets protect the wire at these various points of entry. However, the best thing you can do to ensure a safe electrical system is to ensure the whole system is grounded and the ground circuit is electrically continuous without any breaks.
Checking Branch Circuits
The first step of fixing a tripped circuit should be taken before a circuit trips. If you haven’t already done so, list all the branch circuits in your home by number and by what area each one controls. Then, you can determine which receptacles and fixtures are on each branch circuit. If you aren’t sure the list is accurate and complete, you can verify it with a simple procedure.
Remove a fuse or trip a circuit breaker to its OFF position, then check to see what equipment or devices are de-energized. Of course, it’s easy to see when a ceiling light goes out, but you can check a receptacle just as easily by plugging in a lamp. A small night light is an ideal indicator. Once you know which receptacles, fixtures, and appliances are connected to each branch circuit, write all the information on a card and attach the card to the door of the main entrance panel.
How to Restore a Circuit
The fuses or circuit breakers in your home electrical system are there for a purpose: to blow or trip if the circuit is overloaded. When that happens, as it does from time to time in almost every home, what do you do?
Identify and Disconnect
When a circuit goes off, there may be some visual or audible indication of the trouble spot, such as a bright flare from a lamp or a sputtering, sparking sound from an appliance that immediately leads you to the source of trouble. If so, disconnect the faulty equipment. Take a flashlight and go to the main entrance panel. Check which fuse is blown or which breaker has tripped, and determine from your information card which receptacles, appliances, and lighting fixtures are on the circuit. Then, disconnect everything on that circuit. You can then inspect those fixtures you can’t easily disconnect for signs (or smells) of malfunction.
Reset the Breaker
Replace the fuse or reset the breaker. If the circuit holds, it’s possible something you disconnected is faulty. Check for short circuits or other problems. If there’s no evidence of an electrical fault in the fixtures, the problem may be that the current draw is too much for the circuit to handle. In this case, some load should be removed from the circuit.
Troubleshooting
If the new fuse blows or the circuit breaker refuses to reset, the problem lies in the equipment still connected or in the circuit cable itself. Check the still-connected items, examining each for faults until you find the offending equipment. If the circuit still goes out when there are no loads connected to it, the wiring is faulty, probably due to a short in a junction or receptacle box or in the cable itself. If you suspect faulty electrical wiring, call an electrician.
A circuit breaker is a remarkably trouble-free device, but occasionally, it fails. The result is that the circuit will not energize, even when it’s fault-free. When a circuit goes out, if the circuit breaker itself has a distinctive burnt plastic smell, if the trip handle is loose and wobbly, or if the breaker rattles when you move it, the breaker has probably failed. Turn off the circuit, check the breaker with a continuity tester, and replace it as needed.
Coping With a Power Outage
What do you do when all the power in the house goes off? Usually, this is due to a general power outage in an entire neighborhood or district, but sometimes, the problem lies in an individual residential wiring system.
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Determine if the outage is isolated to your home.
The first step is to see whether the outage is a general power outage or restricted to your home. If it’s nighttime, look around the neighborhood to see if everyone else’s lights are off. During the day, call a neighbor to see if others are affected. Or, if you have a circuit breaker main disconnect, check to see whether it has tripped to the OFF position. If the main entrance is wired with fuses, pull the fuse block out and free the fuses. Check them with a continuity tester to see if they are still good. When a probe lead is touched to each end of the fuse, the tester light will turn on if the fuse is good.
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Turn everything off.
Go back through the house and turn off everything you can. Then, if you have a circuit breaker panel, flip all the breakers to the OFF position. Once the breakers are off, reset the main breaker to ON. One by one, trip the branch circuit breakers back on. If one fails to reset, or if the main breaker trips off again as you trip the branch breaker on, the source of the trouble lies in that circuit. The circuit will have to be cleared of the fault.
If all the breakers go back on and the main breaker stays on, you’re faced with two possibilities. One is that something you disconnected earlier is faulty. Go back along the line, inspect each item for possible faults, and plug each one back in. Sooner or later, you’ll discover which one is causing the problem, either visually or by noticing that a breaker trips off when you reconnect it. The other possibility is systemwide overloading.
This is characterized by recurrent tripping out of the main breaker when practically everything in the house is running but there are no electrical faults to be found. To solve this problem, you can either lessen the total electrical load or install a new larger main entrance panel with new branch circuits to serve areas of heavy electrical usage and help share the total load. This job requires a licensed electrician.
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Contact the power company.
If the trouble is a general power outage, all you can do is call the power company. If your main breaker is still in the ON position or both main fuses are good, but your neighbors have power, and you don’t, the fault lies between your main entrance panel and the power transmission lines. The reason could be a downed service drop, a faulty or overloaded pole transformer, or some similar problem. Call the power company; this part of your system is their responsibility. If you find a tripped main breaker or blown main fuses in your main entrance panel, the problem lies within the house and may be serious. Do not attempt to reset the breaker or replace the fuses. The difficulty may be a system overload, using more total current than the main breaker can pass. Or there may be a dead short somewhere in the house.
Assembling an Emergency Blackout Kit
Is your home susceptible to power outages due to the local utility company, windstorms, or other problems? Even if it’s not, you would be well served to make an emergency blackout kit that includes the following items:
- Flashlight, battery lantern, or other auxiliary light source for troubleshooting
- Correct and up-to-date circuit directory posted on main entrance panel door
- Tool kit with appropriate tools for making electrical repairs
- Circuit tester, preferably the voltage-readout type
- Two replacement plug fuses of each amperage rating in use, preferably Type S
- Four replacement cartridge fuses, including main fuses, of each amperage rating in use
- One replacement pulls circuit breaker of a rating equal to the smallest size in use or one of each size in use
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One replacement double-pull circuit breaker of each amperage rating in use
Selection of lightbulbs - One replacement duplex receptacle to match existing units
- One replacement single-pole switch to match existing units
- One replacement three-way or other special switches to match existing units
- Wire nuts and electrical tape
With a little preparation and knowledge, you can handle your next power outage without being left in the dark.
