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Electrical Terminology


Amps (Amperage) - Is a measurement of electricity. The higher the number of amps the more electricity you have available to you.

Branch Circuit - Is a circuit attached to a main circuit.

BX Wiring - Also called armored cable; the wiring is enclosed in flexible conduit type sheathing.

Circuit - Wiring from a load center to a series of outlets or fixtures etc. Each fuse or breaker controls one circuit.

Doubled Up Conductors - The wiring of two or more circuits to a fuse/breaker. Possibly a code violation.

Ground Fault Interrupter - Commonly called a GFI or GFCI. These units are installed on exterior outlets, or in areas where there is a water source (bathroom or kitchen sink) near the outlet. GFI units are designed to protect people from electrocution from hazardous ground faults or short circuits by automatically turning off electricity when a fault is detected. There are two types available, one replaces a standard circuit breaker with a special GFI circuit breaker. The other is a GFI protected outlet that takes the place of a regular outlet. When installed, this outlet will also protect all the outlets "down the line" from it on the circuit

Ground - Electrical systems must be grounded to provide a safe service. The ground acts as a safety device in case of a short circuit. It takes electricity out of the system sending it to ground, which is a copper rod hammered into the ground beside your home.

Grounded Outlets - These outlets are distinguishable by their three-hole pattern. On this type of outlet the ground hole is wired to the ground system in the home.

Knockouts - Pre-punched sections/blanks that can be removed to connect electrical conduit to a load center or junction boxes. They can also be located on the front panel of a breaker board.

Knob and Tube Wiring - Old style of wiring recognizable by porcelain knobs that hold the single strands of wire and the tubes that insulate the wires as they pass through rafters or floor joists. In some cases this wiring is acceptable. In most cases previous homeowners adding outlets or lights might have tampered with it. An evaluation by an electrician is strongly recommended if this type of wiring is present.

Load Center - The fuse board or breaker panel that distributes the incoming electrical power to the various circuits in the home.

Over Fused Circuit - A circuit for the fuse or breaker where the amperage is too high for the wiring. This is a dangerous condition!

Open Ground - Commonly found on electrical outlets, this means that the outlet does not have a properly attached ground wire. This is a dangerous condition and needs repair.

Open Junction Box - Electrical junction box without a cover. All junction boxes must have a cover.

Overhead Service - Where the incoming electrical service is aboveground.

Overloaded Circuit - A circuit that has too many electrical outlets, switches, etc. for the wiring and or breaker size. Dangerous!

Reversed Polarity - Usually noted on outlets. This condition means that the hot and the neutral wires have been reversed.

Service Drop - The overhead service connection from the utility pole to the house.

Service Panel - see load center

Short Circuit - Result of the hot and neutral wires being crossed; improper wiring, a wet appliance etc. Not good!

Voltage - Most electrical accessories in the home use 110 volts. Voltage is like horsepower; it is a measure of the electricity's strength. Large appliances, i.e. stoves, electric clothes dryers, central air, hot tubs use the larger 220 volts.

Underground Service - This is where the incoming electrical supply for the home is buried underground.

Ungrounded Outlets - Older style outlet that only accepts two-pronged plugs. These outlets do not have a ground wire. While they are acceptable in homes with older type wiring, they are not as safe as grounded outlets.

U-Guard - A plastic shield that protects electric wires on the side of utility poles or a house. It is recognizable by its gray color.

Weather Head - The steel pole mounted on the home to which the incoming overhead electrical supply is attached.