Published onOctober 8th, 2020
Electricity 101: Basic Terms and Concepts
If you have property in New York City, whether you’re a single-family homeowner or manage a large apartment building, it’s helpful to understand basic vocabulary and principles related to construction and the trades. Here’s a list of key electricity terms and concepts from Bolt Electric. When you can speak the language of electricity, you are better equipped to explain your problems to us, as well as to understand what we’re talking about should you need service.
Electricity Terms and Concepts
AC (Alternating Current)
This is the standard type of electricity used in New York City and across the United States.
Amp is short for ampere, which is a unit of measurement for current (see below). The amp rating for an appliance, device, or cable determines how much current it can handle safely. It’s usually within a range of 15 and 60 amps.
This is an undesirable and potentially dangerous situation where electrical current passes between a gap in wiring using the air in the gap to complete the path.
A box is a housing unit for wire connections like those you would find at switches and receptacles (see below), or it’s a place where wires are spliced together (see Junction Box, below). You should always use the largest box possible to give wires and other elements adequate space.
This is a copper bar inside a service panel (see below) or circuit box. Busbars complete the electrical path (AKA circuit, see below) for both neutral and ground wires, either together on one bar or separately for each type of wire.
A circuit is a path of electrical flow on one loop. At the subatomic level, this is the flow of electrons through a conductor (see below). The path begins at a hot wire at the breaker (see below) and ends at the neutral busbar in the panel. For example, when wiring a residence, you may have the living room lighting on one circuit (AKA branch circuit) and the dining room lighting on a separate circuit to avoid overloading any single circuit.
A breaker is a switch in the service panel (see below), rated for the amount of current it can carry in amps. Circuit breakers are designed to shut off instantly and cut the flow of electricity to the related circuit if there is an overload or short circuit (see below). The bigger the appliance on a circuit, the higher the breaker rating.
A conductor is a material that allows electricity to pass through it. Most metals make excellent conductors, especially copper, which is why it is favored for wiring.
This is a tube or pipe through which electrical cable (wires in a protective sheath) passes. Conduits protect cabling from exposure and potential damage.
Current is simply electricity flowing from one location to another. Its volume is measured in amperes (AKA amps).
This is the diameter of electrical wire. The higher the number is, the thinner the wire will be.
Ground Fault Interrupter (GFI)
Also known as a ground fault circuit interrupter or GFCI, this is a safety device that breaks the flow of electricity if aberrations in current are detected, such as exposure to fluids like water. You will therefore frequently find GFI receptacles (see below) in kitchens and bathrooms, where they are required for safety purposes. You may also find GFI circuit breakers being used to protect the entirety of a branch circuit.
A grounding wire is used in modern-day electrical circuits to carry current to ground if there is an accidental short (see below). This prevents current from being transferred to a human, which would cause a shock or possibly electrocution.
This is a wire that’s carrying current in a circuit, also known as a live wire. Hot wires are typically coated with an insulator (see below) and colored red or black.
This is a material that resists electrical flow, such as vinyl plastic. At the subatomic level, insulators inhibit the flow of electrons from one atom to the next. Insulators are designed to contain electrical flow to prevent short circuits and even electrocution.
A junction box is a protective box where cables or electrical wiring are spliced together.
This is a tool that measures electricity.
Non-Metallic (NM) Cable
This type of cable is electrical wiring within a plastic sheath. Frequently found in residential wiring inside walls, NM cable is used for safety purposes.
Ohms measure the amount of resistance (see below) in a circuit.
A receptacle is just another name for an electrical outlet. It allows appliances and electronic items to tap into the electrical circuit. Most people are familiar with duplex wall receptacles that accept two electrical plugs, although there are other sizes available. Receptacles are sometimes called sockets by mistake, but a socket is technically the part of a light fixture where the bulb or tube screws in.
Resistance is opposition to electrical current flow, measured in ohms (see above). Conductors offer little resistance, whereas insulators offer high resistance. Resistance can be harnessed to create heat through friction, such as in the coils of a toaster. However, resistance in electrical cords can be a fire hazard. That’s why electronics use as short a cord as possible and why it’s not always recommended to use extension cords for certain items.
This is a fancy name for a dimmer switch. It works by altering the voltage going through it. A rheostat draws on the amount of available current, so depending on what else is operating on the same circuit, there may be more or less voltage available at any given moment. Rheostats do get slightly warm when operating. They can overheat and become unsafe if they are running more wattage (see below) than they are designed for.
Nowadays, this is most often a circuit panel, but it may also be a fuse box in older properties. Electricity coming into the building from the street enters through the service panel, where it is then distributed to the various branch circuits inside via the circuit breakers.
This is the accidental flow of electricity from a circuit to a conductor that’s not part of the circuit. This should cause a circuit breaker or GFI receptacle to trigger, shutting off the flow of electricity to prevent safety hazards.
A switch loop is a loop created by a cable going between a light fixture and a wall switch for on/off purposes.
Measured in volts, voltage is the force that causes electricity to flow. Also called the electromotive force or EMF, it is caused by a difference in potential between one end of a circuit and the other. For example, 120 volts would be available at the circuit breaker and would flow to the zero volts at an overhead light once the toggle switch is flipped to the “on” position.
Wattage is how electrical power is measured. It is the rate of energy used, such as by an electric heater or a lightbulb. Wattage is the product of amps times volts (amps x volts = watts).
Need more help understanding the electricity in your property or want to book an appointment for service? Call Bolt Electric at 212-434-0098 or use our easy online form to schedule at your convenience.