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NEC Article ______ defines breakers and fuses.
According to NEC Article 100, a device that opens and closes a circuit by nonautomatic means automatically closes for a predetermined overcurrent.
Annex _____ of NEC covers conduit fill.
Annex C of NEC covers conduit and tubing fill for conductors and fixture wire fill.
NEMA stands for National Electrical Manufacturers Association
True - NEMA is the acronym for National Electrical Manufacturers Association.
What does it mean when a receptacle has "NEMA 5-20R" on it?
A receptacle with NEMA 5-20R on it has an amperes rating of 20, will take a NEMA-5-15P or NEMA-5-20P plug, and has a voltage rating of 125.
NEC Tables 310-10 through 310-21 provide information on.
The sizes of copper and aluminum wire, as well as the coating of wire that has fewer than three current carrying wires in a cable or conduit or that is buried in the earth.
Which NEC tables(s) cover(s) the fill of metal boxes?
The fill of metal boxes appears in NEC Tables 314.6 A and B.
Which NEC articles cover the installation requirements for RMC, IMC, and EMT?
NEC Articles 342, 344, and 358 outline the installation requirements of RMC, IMC, and EMT.
IN NEC 2008, what does Table 370.6A cover?
Shows in two columns (milimeters and inches), how many wires in trade size you can place in a box.
What NEC table would you go to to find trade size of conduit and raceway size?
Chapter 9, Table 4 outlines trade size of conduit as well as raceway size.
NEC Articles _____ and _____ covers metallic and non-metallic raceways in buildings.
NEC Article 386 covers metallic or metal raceway; NEC Article 388 covers PVC pipe.
The Panel Board requirements for Application in Construction appear in NEC Article?
NEC Article 408 covers panel board applications.
The smaller kitchen counter requiring a receptacle is _____ inches.
A 12in. counter requires a receptacle because it holds small appliances.
What new code is needed for protection in all habitable spaces?
According to new codes, ARC fault protection is needed many additional parts of the house.
A 12-foot hallway requires one receptacle to meet code. (True or False)
True, One is required, Two are suggested.
NEC section 250-28A provides information on what material can be used for a main bonding jumper. (True or False)
A subpanel requires a bonding screw? (True or False)
False, A bonding screw is unneeded in a subpanel.
Name the methods of sizing bonding jumpers outlined in NEC Section 250-28D.
1. Bonding jumper is sized not less than 12.5% of the largest phase conductor.
2. Based on the largest ungrounded service conductor.
3. Based on the largest sum of the service conductors.
Which NEC reference identifies wire sizing and the temperature a wire can handle in amps?
NEC Tables Annex C1 and C2 identify both wire sizing and the temperature a wire can handle in amps.
Define a grounding system according to NEC.
A gounding system is connected to the ground or to a conductive body that extends the ground connection.
What is the NEC definition of a circuit breaker?
A device designed to trip when an overcurrent is detected.
______ are the subject of NEC Section 680-20.
Electrical installations at permanently installed pools.
Which NEC sections covers identification of equipment grounding conductors?
NEC Section 250-119 1-14
NEC Section 250-134 provides information on what topic?
Equipment fastened or connection between metal parts.
What is the proper procedure for bonding a motor conduit with metal flex?
A bonding jumper should be installed inside or outside raceway within 6ft. of attachment. (NEC 250.118)
Shoulder fittings with locknuts are allowable as bonding devices? (True or False)
True (NEC 250.92B)
What kind of information does NEC Section 250-66 cover?
Covers the sizes of alternating current grounding electrode conductors.
Give guidelines for using sheet metal screws as bonding agents.
Electricians can use sheet metal screws for bonding when those screws are green and have hexagonal heads (NEC 250.8), but it is generally considered unwise.
According to NEC, trees are approved service conductors. (True or False)
False, NEC does not approve tress as service conductors.
When a service entrance wire is under at least 2 in. of concrete, a disconnect is required between meter base and panel. (True or False)
False, No disconnect is required.
Above sidewalks accessible by pedestrians, a service drop not over 600V must be at least _____ft. high.
What is the service drop distance, in feet, of a 200-amp service crossing residential property?
According to NEC 230.9(A), an unsheathed service conductor must be _____ft. from a window that opens.
When bonding a plumbing system to the electrical system, it is not necessary to jump the water meter as this connection is built into the meter. (True or False)
False, run ground wire from panel to copper water pipe then jump the water meter using grounding clamps.
Explain the proper way to ground a subpanel in the same building.
To ground a subpanel in the same building, run a four-wire system from main panel to subpanel.
Discuss the proper way to ground a subpanel in another building.
To ground a subpanel in the another building, run bare copper wire from subpanel to ground rod inside or outside.
Something that is ______ is connected to ground or to a conductive body that extends the grounding connection.
Describe a grounding conductor.
A grounded conductor is a system or circuit that is intentionally grounded.
Define the term grounding conductor.
A grounding conductor is a conductor or circuit of a wiring system to a grounding electrode (ground rod).
What determines the severity of an electrical shock?
Voltage level, amount of protective clothing, and moisture on skin or outerwear all impact a ground connection.
Grounding reduces the voltage that might cause a fatal electrical shock by allowing excess current to flow to the ground. (True or False)
_____ and ______ are two types of electrical faults.
Ground and Arc are two types of electrical faults.
NEC allows electricians to ground gas pipes to existing, grounded water pipes. (True or False)
True, when those water pipes are grounded.
When is building steel permitted in an electro grounding system?
When only the steel is connected to earth ground.
_____ determines what size ground wire used on a service.
The size of the largest conductor determines what size ground wire used on a service.
What is meant by the term isolated grounded reciprocal?
An isolated grounded reciprocal is a separate ground from a device directly to a panel.
Explain the process of cad welding?
Exothermic welding involves the fusion of metal materials or copper to rebar.
Electricians may use rebar as a grounding means. (True or False)
True, Electricians may use rebar as a grounding means.
Electricians must use a(n) _____ to properly connect number 4 copper to a ground rod.
A Direct burial clamp is needed to properly connect number 4 copper to a ground rod.
Using NEC Section 250-8, identify five methods of making connections.
1. ed Pressures Connectors
2. Terminal Bars
3. Pressure Connectors ed As Ground and Bonding Equipment
4. Exothermic Welding
5. Machine screw-type fasteners that engage not less than two threads or are screwed with nuts
Underground service is simpler to troubleshoot and repair than overhead service? (True or False)
Relative to underground service, overhead electrical service is simpler to troubleshoot and repair and is the easier option when running electricity across roadways, waterways, and right-of-ways.
In NEC, Table _____ provides the sizing of grounding electrode conductors.
NEC 250.66 provides the sizing of grounding electrode conductors
Describe the process for bonding three 200-amp disconnects to make a proper grounding system.
To make a proper grounding system using three 200-amp disconnects, use a ground wire of sufficient size to go from panel to panel with a lug, screw, or ground bar, if provided.
In terms of AWG, what is the minimum grounding conductor size permitted?
The smallest grounding conductor permitted is 6 awg or larger.
The way to ground a transformer in a commercial building is to place a grounding rod inside the building? (True or False)
False, The way to ground a transformer in a commercial building is to place a grounding rod outside or beneath the building.
Why do stoves require a four-wire system?
Two hots are needed to operate the stove neutral. The timers and clocks can serve as ground for tripping mechanism.
Why do dryers require a four-wire system?
Two hots are needed to operate the heater neutral. The timers can serve as ground for tripping mechanism.
Air-conditioning units, hot water heaters, and baseboard heat require a four-wire system? (True or False)
False, a A/C unit needs only 220 and a ground to complete the circuit.
Which of the following NEC sections outlines which air-conditioning systems requires no grounding?
Explain where and why isolated systems are used.
Isolated systems are used in healthcare facilities due to explosive gases.
Electricians should put grounded conductors on yellow reciprocal screws? (True or False)
False, grounding conuctors belong on the green screws.
On a 200-amp service, the electrician should use _____ or _____ size grounded conductor in the service cable.
2/0 or 4/0
When using 500 MCM, _____ or ______ size ground wire is appropriate on a 400-amp service.
350MCM or 400MCM
Name a common application for high impedance grounding.
High impedance grounding is used for grounding radio towers. NEC 250.20(E)
What is the proper way to test conduit for proper grounding?
To test conduit for proper grounding, check ohms or use 120V receptacle and touch to ground to check for voltage.
How does an NEC violation affect the occupancy of an existing installation?
Per NEC 90.4, 510.2, and various local codes, occupancy is permitted in the event of a code violation as long as the occupancy remains unchanged and no hazardous condition exists.
The maximum operating temperature of type FFH-2 fixture wiring is?
Per NEC 402.3, FFH-2 fixture wiring is useable up to 75 degrees C
FMT conductors are appropriate for battery storage areas. (True or False)
False, Per 360.12, FMT is disallowed from battery storage areas
A circuit that cannont cause a fire in a hazardous condition is called a(n) _____ system.
An Intrinsically Safe System.
When local ordinance superseded or administers NEC, NEC uses what phrase?
"Authority Having Jurisdiction (AHJ)"
NEC 90.1(A) states that the purpose of NEC is the "practical safeguarding of _____ from hazards arising from the use of electricity".
people and property
NEC Article 426 recognizes which three kinds of heating systems?
Resistive, impedance, and skin effect.
What is proper phase arrangement when wiring a three-phase panelboard?
Per NEC 450.3, phases must arrange in a particular order: A, B, C, from left to right or from top to bottom as seen from the front.
When installing an autotransformer, it is important to remember to insert an OCPD in series with the shunt winding. (True or False)
False, Per NEC 450.4 a OCPD is no needed.
When NEC Article 100 describes "Feeder" as.
"All circuit conductors between the service equipment, the source of a separately derived system, or other power source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device,"
NEC Chapters 1-4 governs basic practices in effect in hazardous areas, except as modified by specific requirements outlined in NEC Chapter _____.
General-purpose enclosures are NEC approved for intrinsically safe apparatuses. (True or False)
True, Intrinsically safe areas are safe with out enclosure, but enclosure are required for other protections.
Fusing the load side of a transformer sufficiently protects the transformer. (True or False)
False, Fuses on the load side do not protect the transformer.
Per NEC 450.3, when a transformer is enclosed, install _____ fuses at the transformer's primary.
The NEC defines ampacity as,
"the current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating"
Leads to an unused current transformer should be.
NEC 110.23 states that, "Unused current transformers associated with potentially energized circuits shall be short circuited."
In what sections does NEC outline the requirements for appliance calculations?
NEC 220.16 - 220.20 cover appliance calculations.
Typically, transformers are available in one of two types: _____ and _____.
Liquid Filled and Dry Versions
NEC Chapter 9, Table 5, states,
To locate wire type and size to be installed. Repeat for each conductor, keeping a running total. Derate by 40% to ge the total raceway area.
NEC Chapter 9, Table 4, states,
For a raceway to be used. Find a value for area larger than the raceway area calculated previously.
The "3-ft. rule" for clearances around things like control panels is adequate. (True or False)
False, Depending on the location and environment, 3ft. may be insufficient clearance. While grouping apparatuses tightly may save space, repair and maneuvering options are limited should a device fail.
When establishing ground clearance in new construction. It is best to make the ground clearance slightly more than the NEC-stated requirement to provide a margin for error. (True or False)
True, It is a good idea to exceed the requirements by a foot or two.
Service drops must be installed so as to be "readily accessible." (True or False)
False, Per NEC 230.24, Service drop connectors shall not be readily accessible.
Extension cords are acceptable in wet areas. (True or False)
True, Per NEC Article 400, only when rated for wet areas.
The requirements for liquid-filled transformers are the same regardless of the liquid used in the transformer. (True or False)
False, Per NEC 450.23-26 liquid-filled transformers have different requirements based on the dielectric fluid.
Disconnects and switches used with appliances must indicate, on their switches, the on- and off-positions. (True or False)
True, Per NEC 422.35
In a three-phase delta system, the leg with the highest voltage must be _____.
Identified as the "B" leg
Branch circuits must be loaded equally in terms of wattage per unit area. (True or False)
True, Per NEC 210.11
An electrician can safely recess a panel board into a flammable wall. (True or False)
False, NEC 312.3, disallows recessing panels in flammable walls.
All metallic boxes and components must be grounded unless a grounding conductor is absent. (True or False)
False, NEC 314.4, requires all metallic boxes to be grounded.
Nameplates that rate protective devices describe which of the following?
Per NEC 422.11, The size of the breaker to use.
NEC maintains no ampacity requirements for fixture wiring because all fixtures undergo the UL approval process. (True or False)
False, NEC 402.5 defines ampacity requirements for fixture wires.
The calculations for protecting motor circuits are the same as those for non motor circuits. (True or False)
False, Protecting a motor and a motor circuit are two very different things
Per NEC Article 410, luminaires may mount on drop-ceiling tiles. (True or False)
False, ceiling tiles are never appropriate device support.
The requirements for burying 240V conductors are found in NEC _____.
NEC 300.5, provides requirements up to 600V
A garage door opener is considered an appliance for NEC purpose. (True or False)
True, Per NEC 422.31
Appliances with motors over 0.125 hp must have a separate means of disconnect. (True or False)
True, Per NEC 422.31
When running new work over old, hanging a second support from a primary support is acceptable practice. (True or False)
True, Per NEC 300.11 hanging a second support when running new over old is acceptable and a common practice.
Installation of a floor drain in a vault intended for wet transformer(s) is ______.
Per NEC 450.46 only transformers over 100KW require a drain, however installing a drain in case of dielectric spills is good practice.
A TVSS provides adequate protection against lighting strikes. (True or False)
False, a TVSS is only for protecting against predictable anomalies, and short-duration spikes of high-voltage.
It is possible to violate the NEC by tightening a bolt or fastener too tight. (True or False)
True, all equipment must be installed per manufacturer's instructions and specifications, The apparatus is void and violates NEC if this is not done.
When installing a cable tray, only the sections nearest the terminations must be grounded. (True or False)
Per NEC 392.7(B) Bonding of all cable tray sections is required.
How would demand be calculated in a commercial environment in which a branch circuit could effectively handle 20 KW?
Per NEC 220.13, use 100% of the first 10KW and 50% of the demand above 10KW. In this case, the demand factor would be 10,000 plus half the remaining 10,000 or 15,000W
NEC allows how many disconnects per service entrance?
Per NEC 225.34, a maximum of six disconnects are allowed per service entrance.
Overcurrent insufficient to trip a breaker can prove hazardous under the right conditions. (True or False)
Name 3 situations AFCI protection is required.
1. Branch circuit in which the initial run is encased in AC up to the first receptacle, which is mounted in a plastic box.
2. Branch circuit in which the initial run is encased in AC up to the first receptacle, which is mounted in a metal box.
3. clothes closet measuring more than 10 sq ft.
In a multiphase system in which one phase is used as a single-phase source, which conductor serves as ground?
Per NEC 250.26, The Neutral conductor serves as ground.
Property owners can act as their own AHJs. (True or False)
Per NEC 100, Property owners can act as their own "Authority Having Jurisdiction" (AHJ)
What demand factor applies when calculating loading requirements for an apartment building with 21 units? A building with over 100 units?
Per NEC 220.84, A 21 unit building would be rated at 32% and any occupancy over 62 units rated at 23%
NEC defines "Bonding" as,
"The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed."
NEC Table 250.66 applies to the derived conductors of separately derived AC systems. (True or False)
A ground ring encircling a building or structure, in direct with the earth consisting of at least _____ft. of bare copper not smaller than _____ AWG, shall be permitted as an electrode.
20ft. of bare copper not smaller than 2 AWG
Where a main bonding jumper or a system bonding jumper is a screw only, the screw shall be identified with a _____ finish that shall be visible with the screw installed.
NEC Table 220.42 can be used to calculate lighting loads in a restaurant dining area. (True or False)
False, demand factors of lighting does not apply to this table.
Outdoor lighting installations exceeding _____ are subject to the clearance requirements outlined in NEC 225.7
Open conductors belonging to separate circuits must be separated by?
Per NEC 225.14, separated by 4in.
A tree over 50 ft. high may be used as an overhead service support for a single-story residence only. (True or False)
Per NEC 230.10, vegetation is disallowed as a support device.
What is the maximum number of sets of service conductors a service drop or lateral may supply?
Per NEC 230.40, "Every service drop or lateral shall supply only one set of service entrance conductors."
The maximum amount of electrical current a conductor or device can carry before sustaining immediate or progressive deterioration.
Is a measure of the amount of electric charge passing a point in an electric circuit per unit time.
In electric circuits, a load usually converts electrical energy to _____, _____, or _____.
Heat, Magnetism, and Light
A circuit has a source of 10V and a resistance of 2hm. A fuse in this circuit should have what value?
Using ohms law, the fuse value would be 10V/2ohms or 5 amperes. However, if the voltage increased slightly and harmlessly, the fuse would blow. Therefore the fuse should be based on the nature of the load.
In electrical work, electrons are always balanced between two points. (True or False)
False, The term electricity is defined as the imbalance in the negative charges, or electrons, between two points.
Differentiate between AC and DC.
In DC, electrons flow in one direction only. In AC, electrons "saw" back and forth in the load. AC is easier to manufacture and is most often delivered and used in a residence, business, or factory.
Which of the following is not a conductor? Gold, Silver, Copper Water, Air.
Air, does not conduct electricity.
Insulators like air, paper or rubber prevent arcing. (True or False)
False, Arcing is the phenomenon in which electrons jump across insulators to positive terminals, which can occur through air, paper, rubber, or any other insulator.
A circuit using 2 amps of current with 12V applied dissipates how much current?
Given that power equals voltage times resistance, power in this example is 24 watts (2amp x 12V)
All electrical equipment and supplies should be considered _____ until determined otherwise.
active or live
A voltage of 1V applied across a 1ohm resistance produces a 1amp current. If the voltage is doubled and the resistance is halved, the current does what?
The current stays the same cause the doubling is offset by the halving.
All voltages in a circuit are referenced to Earth ground via a black wire. (True or False)
False, via a green wire
Define a parallel circuit?
In a parallel circuit, each load is connected in a separate path. In a circuit schematic, the branch lines are parallel.
The most important aspect of becoming an electrician is learning about _____.
Safety is the most important aspect of an electrician's job.
A transformer has a voltage ratio of 8:1 and an input of 120V. What is the output Voltage?
When an ammeter is connected in parallel with a load, ______.
Damage may occur in the meter and or personal injury.
Motors and generators work the same way. (True or False)
True, motors convert electricity to rotational motion, while generators convert rotary motion to electricity.
The organization that sponsors the NEC, is the _____.
The National Fire Protection Association (NFPA) sponsors the NEC
The negative terminal of a battery has a surplus of protons.(True or False)
False, The negative terminal has a surplus of electrons and the positive terminal has a surplus of protons
Which of the following lacks insulation properties? Rubber, Air, Water, Mica, Paper
Water, lacks insulation qualities because it conducts electricity. As a result, it is one of the most hazardous substances in an electrical environment.
In the standard U.S. system of wire sizes, from No.50 through No.4/0, the lower the number the _____ the wire.
The thicker the wire. Gauge was designed to reflect the number of wires that can fit through an opening.
The major cause of death from electrical shock is _____.
Heart fibrillation is the major cause of death from electrical shock. The shock disrupts the normal electrical brain to heart signals.
As the diameter of wire increases, resistance to flow increases. (True or False)
False, the smaller the diameter increases resistance to flow.
If you have 750 watts total in bulbs, how many amps is it at 120V?
6.25amps, 750 watts divided by 120V is 6.25amps
If you have 1,800 watts for baseboard heat, at 240V how many amps are there?
7.5amps, 1,800 watts divided by 240V is 7.5amps
A home has dimensions of 28 x 52 ft., which includes a 28 x 12 ft. garage. What is the home's total living area in square feet?
Because garage space is not considered livable space, subtract its area from the total living area. The home's livable area 28 x 40 is 1,120ft.
How many watts should be allocated per square foot in a residence?
NEC requires a minimum of 3 watts per residential sq ft. The kitchen may require more for better lighting.
A finished basement should have GFCI protection.
Although not required by NEC, in general any receptacles below grade, including those in finished basements, should be GFCI protected. Receptacles in dwelling accessory building with floors at or below grade level require GFCI protection. unfinished basements require GFCI-protected receptacles.
A receptacle or a switch with 14-2 entering it counts as _____ cubic inches.
Each receptacle or switch counts as 2 conductors, and 14 AWG wire conductors require 2 cu.in. each. Therefore, 2 conductors x 2 cu.in. = 4 cu. in. Add to this 2 for the yoke and 2 for the ground for a total 0f 8 cu.in.
Which of the following is considered a service ground?
1. water pipe
2. ground rod(s)
3. ceramic well housing
4. chain link fence post
Water Pipe, A grounding system designed as a main service ground takes priority over a system that provides grounding alone. While requiring as large a grounding surface area as possible is advantageous, the grounding system must be able to support the service on its own.
According to good engineering practice, a sump pump requires a dedicated circuit.
True, like a refrigerator the appliance should continue running when another component fails, the grounding system must be able to support the service on its own.
How many cubic inches does each wire take for:
14 gauge ________.
12 gauge ________.
10 gauge ________.
14 gauge; 2
12 gauge; 2.25
10 gauge; 3
What is an outlet?
According to the NEC, an outlet is defined as a point in a circuit at which current is taken.
What are NEC requirements for a receptacle on a peninsula?
Receptacles must be installed on a peninsula when the peninsula's long edge is at least 24in. and its short edge is at least 12in.
What is the approach for determining the number of receptacles on a 20-amp circuit?
First determine whether the application is residential. For residential applications, the NEC provides no guidance. The answer for nonresidential applications is based on box fill. For these applications, most electricians calculate between 1 and 1.5 amperes per receptacle.
A whirlpool tub requires GFCI protection. (True or False)
Per NEC 680.90(A), GFCI protection Must reside on whirlpool tubs.
What three areas of a residence require 20-amp circuits?
Three residential areas that require 20-amp circuits are the kitchen, bathroom, and laundry room.
In front of a panel from floor to ceiling, how much clearance depth is needed?
NEC requires a clearance width of 30in. and a clearance depth of 36in.
Is a receptacle needed close to an air-conditioning unit? If so, how close must it be?
Yes, a receptacle is required in close proximity to an air-conditioning unit. At most, it must be 25ft. distant.
An attic with a furnace requires a receptacle. (True or False)
True, An attic with a furnace requires a receptacle to honor safety and sound wiring requirements.
A _____-amp breaker goes on a 12 AWG wire.
Although a 15amp breaker is above code, it is preferable when considering expansion.
A metal fence should be attached to a ground rod?
Per NEC 250.116 ground rods should attach to metal fences
It is proper procedure to install an exhaust fan and light in a shower area. (True or False)
False, unless it is 8ft above the rim of the shower zone and ed for wet environments.
All new wiring receptacles must be grounded to a neutral bar in the panel box. (True or False)
True, Receptacles fed from subpanels must have their equipment grounding bar that is electrically isolated from the neutral bar.
Identify four parties who should be satisfied with the electrical work in a new residence.
1. The Builder