Electricity 3 Final Study Guide

A cable, raceway, or box installed under metal-corrugated sheet roof decking shall be supported so the top of the cable, raceway, or box is not less than ______in. from the lowest surface of the roof decking to the top of the cable, raceway, or box

1 1/2

When installing PVC conduit underground without concrete cover, there shall be a minimum of ________ in. of cover.

18

Receptacle outlets shall be calculated at not less than ____ volt-amperes for each single or for each multiple receptacle on one yoke

180

Conductor adjustment factors shall not apply to conductors in raceways having a length not exceeding _____ in.

24

Adjustment Factors must be used if more than ______ current carrying conductors are grouped together in a conduit or cable without maintaining spacing

3

NEC Article ____ contains the rules and table for establishing the ampacity of conductors.

310.14

Within Sight

50ft

In straight pulls, the length of the box or conduit body shall not be less than _____ times the trade size of the largest raceway.

8

where 6 current carrying conductors are run in the same conduit. ampacity of each conductor shall be lowered to what percent of compacity?

80%

Continuous Load

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

Dry Location

A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.

Panel boards shall be mounted in _____ and shall be dead-front

Cabinets, cutout boxes, identified enclosures

Ohm's Law for DC

E=IxR

Grounding, electrode, conductor, or supply side bonding jumper's or conductors shall not be permitted within raceways containing service conductors.

False

Supplies only one utilization equipment

Individual Branch circuit

Damp Location

Locations protected from weather and not subject to saturation with water or other liquids but subject to moderate degrees of moisture.

Each switchboard, switchgear, or panelboard, if used as service equipment, shall be provided with a ____

Main bonding jumper

Power formula for DC

P=IxE

When mounting an enclosure in a finished surface, the enclosure shall be _____ secured to the surface by clamps, anchors, or fittings identified for the application.

Rigidly

The ____ shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.

Service Disconnecting means

The ampacities listed in 310.16 do not take ____ into consideration

Voltage Drop

Accessible (as applied to equipment)

admitting close approach; not guarded by locked doors, elevation or other effective means

Each cable entering a cutout box _____.

shall be secured to the cutout box

The interior of underground raceways shall be considered a _______ location.

wet

Ground fault protection shall be provided for solidly grounded wye electrical systems of more than 150 volts to ground, but not exceeding 1000V phase to phase for each individual device used as a building or structure main disconnecting means rated ____ or more, unless specifically exempted.

1,000A

Ground-Fault Protection of Equipment shall be required for a feeder disconnect if rated _____

1,000A, 208V

Sign and outline lighting outlets shall be calculated at a minimum of ____ volt-amperes for each required branch circuit specified in 600.5(A)

1,200

In general, the minimum size conductor permitted for use in parallels installations is ____ AWG

1/0

According to the NEC, the volume of a 3 x 2 x 2 device box is _____ cu in

10

When counting the number of conductors in a box, a conductor running through the box with an unbroken loop or coil not less than twice the minimum length required for free conductors shall be counted as _____ conductor(s).

2

NEC Article ____ allows the next higher standard overcurrent device rating (above the ampacity of the conductors being protected) to be used with restrictions. This can be thought of as the "next size up" rule.

240.4(B)

At least one 125V, single phase, 15A or 20A rated receptacle outlet shall be installed in an accessible location within ____ ft of the indoor electrical service equipment and be located within the same room or area as the service equipment

25 ft

The required working space for access to live parts of equipment operating at 300 volts-to-ground, where there are exposed live parts on both sides of the workspace is _____ ft.

4ft

The total voltage drop in a feeder should not exceed ______ percent

5

Where angle or U pulls are made, the distance between each raceway entry inside the box or conduit body and the opposite wall of the box or conduit body shall not be less than _____ times the trade size of the largest raceway in a row plus the sum of the trade sizes of the remaining raceways in the same wall and row.

6

Conductor ampacity shall be determined using the ______ column of table 310.16 for circuits rated 100A or less or marked for 14AWG through 1AWG conductors

60C

When Type NM cable is used with nonmetallic boxes not larger than 2 1⁄4" x 4" securing the cable to the box shall not be required if the cable is fastened within _____ in. of that box.

8

When installed in a raceway conductors _____ AWG and larger should be stranded

8

Conduit Fill Chart

Annex C

Ohm's Law for AC

E=IxZ

Is a branch circuit that supplies two or more receptacles or outlets used for appliances or lighting.

General purpose Branch Circuit

Metal boxes shall be _____ in accordance with Article 250.

Grounded and Bonded

Working space ____ must not be less than 6.5 feet or at least as high as the equipment

Height

Wet Location

Installations underground or in concrete slabs or masonry in direct contact with earth; in locations subject to saturation with water or other liquids; and in unprotected locations exposed to weather.

Type MC cable is a factory assembly of one or more insulated circuit conductors with or without optical fiber members enclosed in an armor of ____ metal tape, or a smooth or corrugated metallic sheath.

Interlocking

Equipment intended to interrupt current at other than fault levels shall have a(n) _____ at nominal circuit voltage at least equal to the current that must be interrupted.

Interrupting Rating (IR)

Short-Circuit Current Rating

The prospective symmetrical fault current at a nominal voltage to which an apparatus or system is able to be connected without sustaining damage exceeding defined acceptance criteria.

Where one or more internal cable clamps are present in the box, a single volume allowance in accordance with Table 314.16(B) shall be made based on the largest conductor present in the box.

True

____ for circuit breakers and switches shall be closed using identified closures, or other approved means that provide protection substantially equipment to the wall of the enclosure.

Unused Openings

Other than the required interconnections and control wiring, only those conductors that are intended for termination in a ____ of a switchboard or switchgear shall be located in that section.

Vertical Section

The ___ of a fuse or circuit breaker shall not be less than the nominal voltage of a circuit to which it is connected.

Voltage Rating

Working space ____ must be the greater of 30 inches or the width of equipment.

Width

Nonmetallic-sheathed cables can enter the top of surface-mounted cabinets, cutout boxes, and meter socket enclosures through non flexible raceways not less than 18 in. and not more than _______ ft in length if all of the required conditions are met.

10

NEC Article ____ requires that the temperature rating associated with the ampacity of a conductor shall be selected and coordinated so as not to exceed the lowest temperature rating of any connected termination, conductor, or device. This can be though of as the "weakest link" rule.

110.14(C)

The working space in front of the electric equipment shall not be less than _____ in. wide, or the width of the equipment, whichever is greater.

30in

The wiring space within enclosures for switches and overcurrent devices shall be permitted for other wiring and equipment subject to limitations for specific equipment as provided in _________

312.8(A) 312.8(B)

Box Sizes

314.16(A)

Wire Volume

314.16(B)(1)

When pulling three conductors or cables into a raceway, if the ratio of the raceway diameter to the conductor diameter is between 2.8 and 3.2, jamming can occur. With ____ or more conductors or cables, jamming is highly unlikely.

4

Where raceways contain insulated circuit conductors _____ AWG and larger, the conductors shall be protected from abrasion during and after installation by a fitting that provides a smooth, rounded insulating surface.

4

Equipment associated with the electrical installation can be located above or below other electrical equipment within their working space when the associated equipment does not extend more than _____ from the front of the electrical equipment.

6in

Where cables or nonmetallic raceways are installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is ________ the nearest age of the wood member.

Not less than 1 1/4in from

Where the circuit breaker handles are operated vertically, the up position of the handle shall be ____

On

A building or structure by a maximum _____ service(s), unless specifically permitted otherwise.

One

Power formula for AC

S=IxE

Enclosures for switches or overcurrent devices are allowed to have conductors feeding through where the wiring space at any cross section is not filled to more than _______ percent of the cross-sectional area of the space

40

Dimensions and Percent Area of Conduit

Chapter 9 Table 4

Weatherproof

Constructed or protected so that exposure to the weather will not interfere with successful operation.

Water-Tight

Constructed so that moisture will not enter the enclosure under specified test conditions.

A storage type water heater with a capacity of less than 120 gallons or less is considered to be a ____ load

Continuous

Working space ____ is measured from the enclosed dead front

Depth

Building

A structure that stands alone or that is cut off from adjoining structures by fire walls with all openings therein protected by approved fire doors.

Feeder

All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

Ground Fault

An unintentional, electrically conductive connection between an ungrounded conductor of an electrical circuit and the normally non-current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth.

Is a branch circuit that supplies energy to one or more outlets to which appliances are to be connected and that had no permanently connected lighting fixtures

Appliance Branch Circuit

Service conductors do not have overload protection until they reach the main service disconnecting means overcurrent protective device. Therefore, if service conductors are installed inside of a building, they must ____.

Be kept as short as possible

Exposed

Being capable of being inadvertently touched or approached nearer than a safe distance by a person

Accessible, Readily (Readily Accessible)

Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to actions such as to use tools, to climb over or remove obstacles, or to resort to portable ladders, and so forth.

Accessible (as applied to wiring methods)

Capable of being removed or exposed without damaging the building structure or finish, or not permanently closed in by the structure or finish of the building

Areas of Wire Sizes

Chapter 9 Table 5

Each switchboard, switchgear, or panelboard shall be provided with a _____ that identifies every circuit and circuit modification legibly as to its clear, evident, and specific purpose or use.

Circuit directory or Circuit identification

Openings in cabinets, cutout boxed, and meter socket enclosures through which conductors enter shall be _____.

Closed in an approved manner

In walls constructed of wood or other ____ material, electrical cabinets shall be flush with the finished surface of project therefrom.

Combustible

Compression fittings for EMT are classified as raintight and ____-tight types.

Concrete

Fixed Electric Space-Heating Equipment is considered to be a ____ load

Continuous

A ____ overcurrent protective device is one that cuts off a fault current in less than one-half cycle, thereby preventing short-circuit currents from building up to their full available values.

Current Limiting

____ is a zone equal to the width and depth of the equipment and extending from the floor to a height of 6 feet above the equipment or to the structural ceiling.

Dedicated electrical space

Each strap containing one or more devices shall count as a _____ volume allowance in accordance with Table 314.16(B), based on the largest conductor connected to a device(s) or equipment supported by the strap.

Double

____ is the maximum current that the fuse can continuously conduct without interrupting the circuit.

Interrupting Rating (IR)

Identified (as applied to equipment)

Recognized as suitable for the specific purpose, function, use, environment, and application

A ____ system may contain components that have a short-circuit rating lower than the actual available fault current but are listed by the manufacturer to be able to withstand the actual available fault current. Extreme care must be exercised when working on such systems to avoid potentially catastrophic damage.

Series Rated

______ at other than dwelling units shall be legibly field marked with the maximum available fault current, include the date the fault current calculation was performed, and be of sufficient durability to withstand the environment involved.

Service Equipment

The point of connection between the facilities of the serving utility and the premises wiring is called the ____. This can be described as the point of demarcation between where the serving utility ends and the premises wiring begins. The serving utility generally specifies this location based on the conditions of service

Service Point

Conductors other than service conductors shall not be installed in the same ____ in which the service conductors are installed

Service raceway, service cable

The ____ of a piece of equipment (the entire assembly) must be greater than or equal to the available fault current in order for the equipment to withstand the thermal and magnetic forces of a fault without sustaining damage exceeding defined acceptance criteria.

Short Circuit Current Rating (SCCR)

Parallel conductors

Should have the same length, material, and size in circular mil area

Where one or more equipment grounding conductors enter a box, a _____ volume allowance in accordance with Table 314.16(B) shall be made based on the largest equipment grounding conductor.

Single

Guarded

Surrounded by a case, housing, fence, or wall(s) that prevents persons from accidentally contacting energized parts.

Branch Circuit

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

Ampacity

The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.