You don’t have to be an electrician to be knowledgeable about how electricity works. The more you know, the better prepared you can be when problems arise and when to call a Pat Murphy electrician.

Facts And Information Related To Electricity

Circuit Breakers and Fuses

Circuit breakers and fuses are safety devices that break an electric circuit if the amount of electrical current flowing through it exceeds a safe level.  A fuse consists of a strip of wire that melts and breaks if the current exceeds a safe level. A circuit breaker is an automatic device for stopping the flow of current in an electric circuit as a safety measure. In the electric service panel, each circuit has a circuit breaker or fuse designed to interrupt the flow of electricity when too much current is drawn through the circuit. Generally, newer panels use circuit breakers, while older panels use fuses. The service panel has one main circuit breaker or fuse to shut off all power to the house in case of extreme emergency. Once a circuit breaker is tripped or a fuse is blown, some of the appliances that caused the problem should be turned off before the circuit is reset. Switching a tripped circuit breaker all the way to the off position and then back to the on position resets it. Blown fuses must be replaced. If you have a fuse box, you should have spare fuses on hand. Fuses come in different sizes for different circuits. For safety reasons, a burned out low-amp fuse should never be replaced with a higher-amp fuse. For example, do not replace a 15-amp fuse with a 30-amp fuse.

County Electrical Inspections

County electrical inspectors typically inspect all new construction, room additions, basement finishing, etc. The electrician gets the permit and arranges for the inspection. Minor electrical repair, such as replacing an outlet or installing a ceiling fan, is typically not inspected. If in doubt as to whether or not an inspection is required, call the county inspector?s office.

Grounding

The ground leg, the third round leg on most power cords, is designed for safety. The ground provides a path for electricity to travel safely out of the house and into the earth in an emergency. Breaking off the ground leg on a power cord is both dangerous and illegal. By breaking off the ground leg, the homeowner assumes all liability for the appliance or product and voids all manufacturers? warranties.

Insurances

Electricians, like all other companies working at the home, should carry both workers? compensation insurance and liability insurance. You should verify this insurance directly with the insurance company.

Common Electrical Terms

While some homeowners shy away from anything mechanical in their homes, many fancy themselves the next Super Do it Yourselfer. But when it comes to the residential electrical system and its components, every homeowner should have a basic understanding of what that system is and how it works. Not only will this knowledge come in handy when you?re working with electricity, but it also could help keep you and the house safe.

Arc-Fault Circuit Interrupter (AFCI)

The arc-fault circuit interrupter, or AFCI, is a device that monitors the flow of electricity in a circuit. When it recognizes the unique current and/or voltage signatures associated with arcing faults, it interrupts the circuit. New homes are required to have AFCI protection on all bedroom circuits; AFCI circuit breakers located in the control panel are the most common form of protection.

Bonded (Bonding)

Connected to establish electrical continuity and conductivity.

Branch Circuit

The circuit conductors between the final over current device protecting the circuit and the outlet(s).

Breaker Panel

Usually located somewhere within the home, the control panel is the central location of the home?s circuit breakers or fuses. It should contain the individual circuit breakers or fuses, as well as the main breaker switch for the home.

Circuit Breaker

The circuit breaker is designed to open and close a circuit by non-automatic means. If an over-current, or power overload, travels through the circuit, it will trip, or shut off the power for that circuit. Fuses, which were in use before circuit breakers, also protect against over-current. A fusible part is heated and severed if an over-current
passes through it.

Continuous Load

A load where the maximum current is expected to continue for 3 hours or more.

Device

A unit of an electrical system that carries or controls electric energy as its principal function.

Ground

A ground, or grounding electrode, is a rod, pipe or other device that provides a termination point to the earth. Equipment grounding conductors connect the non-current- carrying metal parts of equipment, raceways and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the breaker panel.

Grounded Conductor

A system or circuit conductor that is intentionally grounded.

Grounding Electrode

A conducting object through which a direct connection to earth is established.

Grounding Electrode Conductor

A conductor used to connect the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system.

Ground Fault Circuit Interrupter GFCI

The ground fault circuit interrupter, or GFCI, is an electronic device that monitors the flow of electricity in a circuit. This helps protect against electric shock and electrocution. Most homeowners will recognize GFCI outlets?those outlets with ?test? and ?reset? buttons. These are especially crucial in bathrooms, kitchens, garages, crawlspaces and any other area that is exposed to water.

Meter Base

Located outside the home, the meter base contains the usage meter installed by your utility company.

Switch

Most familiar to homeowners, the switch is used to turn on and off lighting and other electrical equipment. Receptacles in outlets are the point at which we plug in items requiring electricity. And an uninterrupted power supply is a device that utilizes a battery to keep the power going if the electricity is cut off.

Basics of How Electricity Works in the Home

Armed with some of the basic terminology, there are three basic components that make up any electrical system: power supply, circuit wiring and protection, and the load.

The power supply is the electricity that runs through the system. The circuit wiring is the wiring that connects all the components of the system. No. 12 gauge copper wire is the most common for residential wiring. This conductor can carry up to 20 amps of current safely. Circuit breakers or fuses work to protect the system.

The load is anything that uses electricity. This can range from a small night light in the hallway to larger loads such as central heating and air conditioning systems, electric water heaters, electric ovens, air compressors and others.

The data on this page is presented for information purposes only and is not meant to provide advice for performing any type of electrical installation or repair.