2014 NEC Electrical Knowledge

30"

A 14" wide 100 amp service equipment panelboard is installed on the wall in the basement of a building. The Code requires that a space of at least _______ be maintained about this panelboard.

4X or 6P

A housing for a motor controller located in a corrosive environment must have a _______ type enclosure.

7'

A wall, screen, or fence must be ________ tall that encloses an outdoor electrical installation over 600 volts to deter access by unqualified persons.

wooden plugs

According to the National Electrical Code, ______ shall not be used to mount electrical equipment onto a masonry wall.

equivalent to

All splices, joints and free ends of conductors are required to be covered with an insulation _______ the conductor.

100

An underground pull box used for circuits of over 600 volts shall have the cover locked, bolted or screwed on, or the cover is required to weight over _______ pounds.

CM

Conductor sizes are given in AWG and ______.

60

Conductors must have their ampacity determined using the _______ •C column of Table 310.16 for circuits rated 100 amps or less or marked #14 through #1 conductors, unless the equipment terminals are listed for use with higher temperature rated conductors.

copper

Conductors shall be _______ unless otherwise provided in the Code.

#10

Connection by means of wire binding screws or studs and nuts having upturned lugs or equivalent shall be permitted for _______ or smaller conductors.

the purpose is evident

Each disconnecting means must be legibly marked to indicated its purpose unless located and arranged so ______.

workmanlike

Electrical equipment shall be installed in a near and ______ manner.

conspicuous

Entrances to rooms and other guarded locations containing exposed live parts shall be marked with _______ warnings signs forbidding unquantified persons to enter.

available

Equipment intended to break current at fault levels shall have an interrupting rating at nominal circuit voltage sufficient for for the current which is _______ at the line terminals of the equipment.

interrupting

Equipment intended to interrupt current at fault levels shall have an _______ rating at nominal circuit voltage sufficient for the current that is available at the line terminals of the equipment.

6"

Equipment such as raceways, cables, wireways, cabinets, panels, etc. can be located above or below other electrical equipment when the associated equipment does not extend more than _______ from the front of the electrical equipment.

24

For equipment rated 1200 amperes or more 600 volts or less, and over 6 feet wide, containing overcurrent devices, switching devices, or control devices, there shall be one entrance not less than _______ inches wide and 6 1/2 feet high at each end.

metal plugs and plates

How would you seal unused ko's in panels and boxes?

mechanical strength and arching effects

In judging equipment, considerations such as the following shall be evaluated:

when the terminal is identified as allowing more than one conductor

It is permissible to install two wires under the same terminal _______.

the instructions included in the listings or labeling.

Listed or labeled equipment shall be installed, used, or both, in accordance with _______.

1/4"

Metal plugs or plates used with non-metallic boxes shall be recessed _______.

200

Minimum headroom shall be provided for all working spaces about service equipment, switchboards, panelboards, or motor control centers except in service equipment or panelboards in dwelling units that do not exceed _______ amperes.

suitable

Only wiring methods recognized as _______ are included in this Code.

Article 225

Outdoor electrical installations over 600 volts that are open to unqualified persons shall comply with _______.

between any circuit conductor and the grounding conductor or enclosing metal raceway and between two or more of the circuit conductors

Overcurrent protective devices shall be selected and coordinated as to permit the circuit protective devices used to clear a fault without the occurrence of extensive damage to the electrical components of the circuit. This fault shall be assumed to be _______.

they extend not more than 6 inches beyond the front of the equipment

Panelboards, switches, gutters, raceways or transformers are permitted to be mounted above or below one another if ________.

balconies, mezzanine floors and platforms

Permanent ladders or stairways shall be provided to give safe access to the working space around electric equipment over 600 volts installed on _______ or in attic or roof rooms or spaces.

26"

Round access openings in a manhole shall not be less than _______ in diameter.

joined mechanically

Soldered splices must be ______ so as to be electrically secure before soldering.

orange

The Code has assigned the color _______ to the high-leg of an4-wire delta connected secondary.

trademark and manufacture's name

The _______ , or other descriptive markings by which the organization responsible for the product may be identified, shall be placed on all electric equipment.

approved

The conductors and equipment required or permitted by this code shall be acceptable only if ________.

3

The floors of vaults constructed with a vacant space or other stories below it, the floor shall have adequate structural strength for the lost imposed on it and a minimum fire resistance of _______ hours.

4"

The floors of vaults in contact with the earth shall be of concrete that is not less than _______ thick for equipment over 600 volts.

Enclosures or guards

The following must be provided in locations where electrical equipment would be exposed to physical damage:

6' 6"

The minimum headroom of working spaces about control centers shall be _______.

no minimum illumination

The minimum illumination permitted by Code about service equipment, switchgear, panelboards, etc. operating at less than 600 volts is _______.

42"

The minimum working space in front of a 480 volt panel to a concrete wall is ______.

30"

The width of working space in front of electric equipment shall be the width of the equipment or ________, whichever is greater.

storage

The work space required by the Code for electrical equipment shall be used for _______.

36"

The working clearance in front of a 2300 volts switchboard to a wooden wall is _______.

36"

The working clearance in front of a switchboard or switchgear shall be not less than ________.

48"

The working space or clearance in front of a 120/208 volt panel to the front of a 277/480 volt panel on the other side of a hallaway is _______.

operates

Through the Code, the voltage considered shall be that at which the circuit _______.

9'

Unguarded live parts above working space shall be maintained at an elevation of ______ for 4160 volts.

9'

Unguarded live parts above working space shall be maintained at an elevation of ________ for 4160 volts.

9.5 '

Unguarded live parts operating at 30,000 volts located above a working space must be elevated at least ______ above the working space.

damp or wet locations and where exposed to gases, fumes, vapors, liquid, etc.

Unless identified for use in the operating environment, no conductors or equipment shall be located in _______ having a deteriorating effect on the conductors or equipment.

50

Unless specified otherwise, live parts of electrical equipment operating at ______ volts or more shall be guarded.

Not less than the height of the equipment

What is the required minimum headroom for electrical equipment that exceeds 6 1/2 feet in height?

reversed

When installing ventilation system electrical controls, they shall be arranged so the airflow can be ________.

With screws driven into wooden plugs in the wall.

Which of the following is NOT an acceptable method of mounting electrical equipment to a masonry wall?

30

Working space for equipment operating at 600 volts, nominal, or less to ground and likely to required examination, adjustment, servicing, or maintenance with exposed live parts on one side shall be _______ inches wide or the width of the panel or enclosure allowing the door (s) to open 90 degrees.

Permanent ladders or stairways

_____ shall be provided to give safe access to the work space around equipment over 600 volts installed on platforms, balconies, mezzanine floors, or in attic or roof rooms or space.

Abrasives

_______ must not be allowed to come in contact with interior parts of electrical equipment.

Leather

_______ plugs driven into holes in masonry, concrete, plaster, or similar materials shall not be used.