Amperes refer to how much electricity is flowing. The more amperes that flow, the thicker the wire needed to carry it. Wire is measured by gauge and National Electric Code specifies wire thickness for specific amounts of current.
Branch Circuits – a branch circuit begins at a circuit breaker in a service panel. The branch circuit may supply a single outlet, a permanently wired appliance or multiple outlets. The most common residential branch circuit has all the outlets for a room including the lighting outlet.
A Connector can refer to either a romex connector or an EMT conduit connector. A romex connector is used to connect romex cable to electrical boxes. EMT connectors are used to connect EMT conduit to electrical boxes.
A breaker panel is the electrical service panel which contains your house breakers. Most homes have an electrical panel outside which holds the main breakers and all of the 220 volt breakers. There can also be another panel inside the house which will contain all the 110 volt breakers.
EMT is a thin walled metal electrical conduit. In the past before Romex was accepted for residential use, Emt was the main conduit product used in construction. Emt conduit did not need to be threaded and was bent to meet the requirements of the job. Emt has fittings such as connectors and couplings in order to connect the individual pieces and connect to metal boxes.
A fuse is a protective electrical device. A fuse is rated for a maximum amount of current flow which is measured in amps. Electrical current is measured in amperes also called amps. When the current flow exceeds the amperage rating on the fuse, the fuse link in the fuse will open and stop the flow of current. Years ago everything, both AC and DC current, were protected with fuses. Today most have been replaced with electrical breakers.
A ground fault circuit interrupter, called a GFCI or GFI, is an electrical device that can either be installed in your electrical system or built into a power cord to protect you from severe electrical shocks. A GFCI constantly monitors current flowing through a circuit. If the current flowing into the circuit differs by a very small amount (as little as 0.006 amperes) from the returning current, the GFCI interrupts power faster than a blink of an eye to prevent a lethal dose of electricity. GFCIs are designed to operate before the electricity can affect your heartbeat. A GFCI works even on two-slot receptacles.
A ground fault is an unintentional electrical path between a power source and a grounded surface. Ground faults most often occur when equipment is damaged or defective, such that live electrical parts are no longer adequately protected from unintended contact. If your body provides a path to the ground for this current, you could be burned, severely shocked or electrocuted.
A ground rod is a copper or aluminum rod which is 1/2 inch (minimum) in diameter and normally eight feet long. It is driven in the ground near the outside electrical service and is used as an electrical ground for the electrical service.
The grounded conductor is often called the neutral wire. Every 120-volt branch circuit requires a grounded conductor. The grounded conductor carries current back to the service panel after it has been used by an appliance. At the main service panel, the grounded conductor connects to earth ground. Grounded conductors must be white or natural gray.
Ground wires – don’t confuse ground wires with grounded conductors. A ground wire attaches to anything that might conduct electricity but is not supposed to. The sheet metal of an electric dryer is a good example. If the hot wire accidentally came loose and touched the metal exterior, someone touching the dryer could receive a shock. A ground wire provides a safe path to ground in the event the hot wire touches something it should not. Ground wires are bare or have green insulation.
A home run refers to the main line that runs from the electrical service panel to the first device in the electrical circuit.
Hot wire – the hot wire in a circuit carries current from the service panel to the outlet. If a circuit is controlled by a switch, the switch must be on the hot wire. The hot wire in wiring is usually black or any other color wire except white, gray or green.
Neutral wire – a true neutral wire only exists on the line that runs between the electric utility transformer and the service entrance or on branch circuits that use a combination of 125 volts and 250 volts. The neutral wire carries the difference between the two hot wires in these circuits.
A receptacle is an electrical device used to furnish an electrical source for electrical tools or appliances. Receptacles are often referred to as outlets. Other outlets include light fixtures for recessed and non-recessed lighting, wall sconces and dryer and range receptacles. Any light fixture is considered a single outlet even though it may have multiple light bulbs. Receptacles can provide either 110 volt or 220 volt supply. Receptacles can also be switched from a light switch to operate a light.
Romex is a particular type of electrical wiring used mainly in new home construction. Romex consists of a certain size wires wrapped in a plastic sheath. A particular type of romex might be marked as 10/3 with ground. This romex cable will consist of 3 runs of colored coded 10 gauge wire and one run of bare copper wire which will be the ground. The colored coded wires should be red, black, and white. The red and black wires will be hot wires and the white wire will be the common wire. This type wire would be used in a 220 volt circuit.
Service panel – the service panel goes by many names, including circuit breaker box, breaker box, circuit panel and fuse box. The main service panel holds the main circuit breaker and the circuit breakers for branch circuits. It may also serve other panels, called sub panels, that also distribute power to branch circuits.
A switch is an electrical device which is used to turn other devices on and off. It does this by opening the electrical connection to the device.
A switch leg is the wire connected to the switch which controls the on and off of the device.
Two gang is a term used to refer to a particular type of electrical box. A two gang box will hold two switches, two receptacles, or one switch and one receptacle.
Wire nuts are used to connect multiple wires together. They provide a good electrical connection after twisting the wire nuts tight.