Chapter 7/8 House Wiring

Triplex Cable

A cable type used as the service drop for a residential service entrance; it consists of a bare messenger wire that also serves as the service grounded conductor and two black insulated ungrounded conductors wrapped around the bare wire

Grounding Electrode

A conducting object through which a direct connection to each is established

Grounding Conductor

A conductor used to connect equipment or the grounded conductor of a wiring system to a grounding electrode or electrodes

Bonding Jumper

A conductor used to ensure electrical conductivity between metal parts that are required to be electrically connected

Brushing

A fiber or plastic fitting designed to screw onto the ends of conduit or a cable conductor to provide protection to the conductors

Porcelain Standoff

A fitting that is attached to a service entrance mast, which provides a location for the attachment of the service drop conductors in an overhead service entrance

Equipment

A general term including material, fittings, devices, appliances, luminaries, apparatus, machinery, and other parts used in connection with an electrical installation

Supplemental Grounding Electrode

A grounding electrode that is used to back up a metal water pipe grounding electrode

Main Bonding Jumpers

A jumper used to provide the connection between the grounded service conductor and the equipment grounding conductor at the service

Riser

A length of raceway that extends up a utility pole and encloses the service entrance conductors in an underground service entrance

Mast kit

A package of additional equipment that is required for the installation of a mistype service entrance; it can be purchased from an electrical distributor

Transformer

A piece of electrical equipment used by the electric utility to step down the high voltage of the utility system to the 120/240 volts are required for a residential electrical system

Sill Plate

A piece of equipment that, when installed correctly, will help keep water from entering the hole in the side of a house that the service entrance cable from the meter socket to the service panel goes through

Service Mast

A piece of rigid metal conduit or intermediate metal conduit that provides service conductor protection and the proper height requirements for service drops

Concentric Knockout

A series of removable metal rings that allow the knockout size to vary according to how many of the metal rings are removed; the center of the knockout hole stays the same as more rings are removed; some standard residential wiring sizes are 1/2, 3/4, 1, 1 1/4.

Pad mounted transformer

A transformer designed to be mounted directly on a par foundation at ground level; single phase pad mounted transformers are designed for underground residential distribution systems where safety, reliability, and aesthetics are important

Utility Pole

A wooden circular column used to support electrical, video, and telecommunications utility wiring; it may also support the transformer used to transform the high utility company voltage down to the lower voltage used in a residential electrical system.

Drip Loop

An intentional loop put in service entrance conductors at the point where they extend from a weathered; the drip loop conducts rainwater to a lower point than the weatherhead, helping to ensure that no water will drip down the service entrance conductors and into the meter enclosure.

Accessible, Readily

Capable of being reached quickly for operation, renewal, or inspections without requiring a person to climb over or remove obstacles or to use portable ladders

Grounded

Connected to earth or to some conducting body that serves in place of the earth

Bonding

Connected to establish electrical continuity and conductivity; the purpose is to establish an effective path for fault current that facilitates the operation of the overcorrect protective device

Rain-Tight

Constructed or protected so that exposure to a beating rain will not result in the entrance of water under specified test conditions

Metal framing, A concrete encased electrode, Ground Ring, Plate Electrode, and Rod and Pipe electrodes

List atlas 5 items, other than a metal water pipe, that could be used as a grounding electrode for a residential service entrance.

Service entrance cable

Service entrance conductors made up in the form of a cable

3

The NEC recommends that both branch circuits and feeder circuits cab be sized to limit the voltage drop to no more than -%

10 ft

The NEC requires a clearance of at least ________ feet above final grade for service conductors where they are connected to the building, above sidewalks and other areas accessible to pedestrians

18 ft

The NEC requires a vertical clearance of at least ________ feet above public streets, alleys, roads, and parking areas subject to truck traffic.

Voltage Drop

The amount of voltage tat is needed to push the house electrical loa current through the wires from the utility transformer to the service panel and back to the transformer; the amount of voltage drop depends on the resistance of the wires and the actual current varied on the wires

Enclosure

The case or housing of apparatus or the fence or walls surrounding an installation too prevent personnel from accidentally contacting energized

Neutral Coductor

The conductor connected to the neutral point of a system that is intended to carry current under normal conditions; the neutral point is the midpoint on a single phase, three wire in this system; the voltage from either ungrounded hot wire in this system to the neutral point is 120 volts.

Equipment Grounding Conductor

The conductor used to connect the concurrent carrying metal parts of equipment, raceways, and the other enclosures to the system grounded conductor, the grounding electrode conductor, or both at the service equipment

Grounding Electrode Conductor

The conductor used to connect the system grounded conductor to a grounding electrode or to a point on the grounding electrode system

Service

The conductors and equipment for deserving electric energy from the serving utility to the wiring system of the premises served

Service Entrance Conductors

The conductors from the service point to the service disconnecting means

Ground

The earth

Service Head

The fitting that is placed on the service drop end of the service entrance cable or service entrance raceway and is designed to minimize the amount of moisture that can enter the cable or raceway; the service head is commonly referred to as a 'weatherhead'

5 feet

The meter socket is typically mounted at approximately --- to the top of the meter enclosure from finished grade

Service equipment

The necessary equipment connected to the load end of the service entrance conductors supplying a building and intended to be the main control and cutoff of the supply

Service Drop

The overhead conductors between the utility electric supply system and the service point

Threaded Hub

The piece of equipment that must be attached to the top of the meter socket so that a raceway or a cable connector can be attached to the meter socket

Service point

The point of connection between the wiring of the electric utility and the house wiring is called the

Service Point

The point of connection between the wiring of the electric utility and the premises wiring

Service Raceway

The rigid metal conduit, intermediate metal conduit, electrical metallic tubing, rigid PVC conduit, or any other approved raceway that encloses the service entrance conductors

Servie entrance conductors, underground

The underground service conductors between the service pint and the first point of connection to the service entrance conductors inside or outside the building wall

Meter Enclosure

The weatherproof electrical enclosure that houses the kilowatt-hour meter; also called the meter socket or meter trim

Roof Flashing/ Weather Collar

Two parts of a mast type service entrance that, when used together, will not allow water to drip down and into a house through the hole in the overhanging section of a roof that the device mast extends through

1) A main breaker panel that is installed inside the house. 2) A combination meter socket/ main breaker disconnect that is installed outside the house.

What are the 2 types of service equipment commonly used in residential wiring systems?

1) Using a service entrance cable installed on the side of house. 2) Using electrical conduit installed on the side of a house. 3) Using a mast style service installation

What are the 3 ways to install an overhead service entrance?

Main Breaker

What do sub panels normally not have?

Utility Company

What group is the final authority for determining the required vertical clearances for service conductors?

4-5 feet

What is the height of the meter socket when installed?

6 1/2 ft

What is the minimum headroom of working spaces around electrical service equipment is --- or the height of the equipment, whichever is greater.

30

What is the minimum width of the working space in front of the electric equipment must be the width of the equipment or --- inches.

8 ft

When installing service drop conductors above a residential roof, conductors must have a vertical clearance of at least ________ .

Intersystem Bonding Termination

a device that provides a means for connecting intersystem bonding conductors for communications systems to the grounding electrode system

Conduit LB

a piece of electrical equipment that is connected in-line with electrical conduit to provide for a 90-degree change of direction

Eccentric Knockout

a series of removable metal rings that allow a knockout size to vary according to how many of the metal rings are removed; the center of the knockout hole changes as more metal rings are removed; common sizes are the same as for concentric knockouts

Grounded Conductor

a system or circuit conductor that is intentionally grounded

Backfeeding

a wiring technique that allows electrical power from an existing electrical pane; to be fed to a new electrical panel by a short length of cable; this technique is commonly used when an electrician is upgrading an existing service entrance

12 in/ 30 in

service entrance cables must be supported by straps, staples, or other approved means within --- -- of the service head or any electrical enclosure and at intervals not exceeding --- --.

Line side

the location in electrical equipment where the incoming electrical power is connected; an example is the line side lugs in a meter socket where the outgoing electrical power conductors to the service equipment are connected

Service entrance conductors overhead

the overhead service conductors between the service point and the first point of connection to the service conductors at the building or other structure

Cable Hook

the part used to attach the service drop cable to the side of a house in an overhead service entrance installation

Backboard

the surface on which a service panel or sub panel is mounted; it is usually made on plywood and is often painted a flat black color

Service Lateral

the underground conductors between the utility electric supply system and the service point