Journeyman Exam Flashcards
What is used to increase or decrease AC voltages?
Transformer
What is the full-load current rating of a 240-Volt, single-phase 10kW commercial dishwasher?
42 Amps
10kWx1000/240=41.6A
I=P/E
What is the full load current rating of a 15 kW, 208V, single phase heat pump?
72 Amps
15kWx1000/208=72A
I=P/E
What is the total resistance of a 10 Ohm, a 15 Ohm, and a 20 Ohm resistor connected in series?
45 Ohms
10+15+20+25=45
RT=R1+R2+R3
The voltage drop for two 12 AWG conductors(0.40 ohms) that supply a 16A load and are located 100 ft. from the power supply?
6.40 Volts
16Ax .40=6.40V
EVD=IxR
What is the purpose of the NEC?
The practical safeguarding of persons and property
90.2(A)
What is the term for a device used to adapt a circuit from one configuration of an attachment plug or receptacle to another of the same current rating?
Adapter
Article 100 Definitions
The NEC defines a conductor’s ampacity as “the maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its:
Temperature Rating
Article 100 Definitions
Connected to establish electrical continuity and conductivity is defined as:
Bonded(Bonding)
Article 100 Definitions
What is the term for insulated conductors enclosed overall in a nonmetallic jacket?
Non-Metallic Sheathed Cable
Article 100 Definitions. Cable, Nonmetallic-Sheathed (Type NM)
A continuous load, as defined by the NEC is a load where the maximum current is expected to continue for___ hours or more?
Three
Article 100 Definitions. Continuous Load
Emergency Power Systems are intended to automatically supply power and/or illumination that is essential for___ and are legally required and classed as emergency by any governmental agency having jurisdiction.
Safety to human life
700.2 Definitions. Emergency Systems
What is a Ground-Fault Circuit Interrupter(GFCI)?
A device to protect personnel that deenergizes a circuit or portion thereof within an established period of time when a ground-fault current exceeds the values established for a Class A device
Article 100 Definitions. Ground-Fault Circuit Interrupter(GFCI)
Connected(connecting) to ground or to a conductive body that extends the ground connection.
Grounded(Grounding)
Article 100 Definitions. Grounded(Grounding)
True or False: Where this code specifies that one equipment shall be “in sight from”, “within sight from”, or “within sight”, and so forth, of another equipment, the specified equipment is to be visible and not more than 15M(50 FT) distant from the other.
True
Article 100 Definitions. In Sight From
Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction is:
Labeled
Article 100 Definitions. Labeled
What is the term for a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating, or of operation of equipment in excess of normal, full load rating? This does not include a ground fault or a short circuit, or any other kind of fault.
Overload
Article 100 Definitions. Overload
The overhead conductors between the utility electric supply system and the service point are known as a:
Service Drop
Article 100 Definitions. Service Drop
Conductors sizes are expressed in___ or in circular mils.
American Wire Gauge(AWG)
110.6 Conductor Sizes
When equipment is intended to interrupt power at fault levels, it must have an interrupt rating at least the nominal___ of the circuit, and the current available at the line terminals of the equipment.
Voltage
110.9 Interrupting Rating
The temperature rating associated with the ampacity of a conductor shall be selected and coordinated so as not to exceed the___ temperature rating of any connected termination, conductor, or device.
Lowest
110.14(C) Temperature Limitations
For a size 6 AWG THHW copper conductor connected to a fusible disconnect switch with terminals rated for 75C, what is the maximum current load, in amperes?
65 Amperes
110.14(C)(1) Equipment Provisions.
Table 310.16
The conductor on a 4-wire, delta-connected system, since it has higher voltage to ground, if the grounded conductor is also present to supply lighting or similar loads, shall be identified by which color?
Orange in color or by other effective means
110.15 High Leg Marking
Disconnecting means shall be capable of being___ in the open position.
Locked
110.25 Lockable Disconnecting Means
In front of electric equipment, the working space width must be at least___, or the width of the equipment, whichever is greater.
30 Inches
110.26(A)(2) Width of working space
In front of electric equipment, the working space must have space for doors or hinged panels to open___ degrees or more.
90 Degrees
110.26(A)(2) Width of working space
Support structures or other equipment for electrical installations, located above or below, may not extend more than___ beyond the front of the equipment.
6 Inches
110.26(A)(3) Height of working space
For the work space in front of a 120/240 Volt, single phase, 400 ampere rated disconnect switch located in a commercial occupancy, what is the minimum required height?
6.5 Feet
110.26(A)(3) Height of working space
The space equal to the width and depth of the equipment and extending from the floor to a height of___ above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation.
6 Feet
110.26(E)(1)(a) Dedicated Electrical Space
How should an insulated grounded conductor 6 AWG or smaller be identified?
3 white stripes on any color insulation but green, a continuous outer gray or white finish or several other options
200.6(A)
Grounded(Neutral) conductors larger than size 6 AWG may be identified by the terminations having__ colored phase tape, at the time of installation.
White
200.6(B)
For devices with screw shells, the terminal for the ___ conductor shall be the one connected to the screw shell.
Grounded
200.10(C)
For conductors on a branch circuit that supplies luminaires in a residence, what is the maximum allowable voltage between conductors on a branch circuit supplying luminaires in a residence?
120 Volts
210.6(A)(1)
True or False: In dwelling units, all 125-volt, single phase, 15- and 20- ampere receptacles installed in the following locations shall have ground-fault circuit-interrupter(GFCI) protection for personnel; areas with sinks and permanent provisions for food preparation, beverage preparation, or cooking, basements, bathrooms, bathtubs, or shower stalls with receptacles installed within (6 FT) of the outside edge, boathouses, crawl spaces- at or below grade level, garages & accessory buildings at or below grade level, indoor damp and wet locations, kitchens, laundry areas, outdoors, sinks with receptacles installed within (6 FT) of the top inside edge of the bowl.
True
210.8(A)
Where should type AC cable not be used?
In damp or wet locations or where subject to physical damage
320.12
Where receptacles in kitchens are made available to serve countertop surfaces, what outlets must be GFCI protected?
All
210.8(A)(6)
What total minimum volt-amperes(VA) shall be included when calculating the demand load for small appliance and laundry circuit loads for a one family dwelling?
4500 VA
210.11(C)
Sinks located in areas other than kitchens where receptacles are installed within__ of the outside edge of the sink, require GFCI protection.
6 Feet(1.8M)
210.8(A)
The total__ load and the rating or size of circuits used will determine the minimum number of branch circuits.
Calculated
210.11(A)
Listed Arc-Fault circuit interrupters should protect all 120-Volt, single phase, 15- and 20- ampere branch circuits in dwelling units, supplying outlets installed in:
Dining, family & living rooms, hallways, kitchens, libraries & parlors
210.12(B)
If a branch circuit served by size 12 AWG conductors is protected by a 15- ampere circuit breaker, what kind of rating does it have?
15 Amperes
210.18
Branch circuit conductors must have an ampacity of at least the __ load to be served, after any adjustments or corrections.
Maximum
210.19
When a branch circuit supplied any combination of noncontinuous and continuous loads, the minimum branch circuit conductor size, before the application of correction or adjustment factors, must have an allowable ampacity of at least ___ of the continuous load plus the noncontinuous load. Exceptions ignored.
125 Percent
210.19
What is the minimum voltage recommended by the NEC for a 40A, 240V rated single phase load that is a total of 200 ft from a panelboard(150 ft from load to junction box, 20 ft from junction box to panelboard) where the panelboard is 240 Volts?
232.8 Volts
240x3%=7.2V
240-7.2=232.8V
215.2(A)(2)
The overcurrent device size required for a 45A continuous load for a circuit in a raceway with 14 current carrying conductors is:
60 Amperes
45Ax125%=56.25A
210.20(A)
215.3
When a 20 ampere branch circuit serves a single receptacle outlet, the rating of the receptacle generally must be at least:
20 Amperes
210.21(B)(1)
What is the maximum rating allowed of any one cord and plug connected appliance connected to a 20 ampere branch circuit?
16 Amperes
20Ax80%=16A
210.23(B)(1)
Appliance receptacles outlets installed in a dwelling unit for specific appliances, such as laundry equipment, shall be installed within ___ feet of the intended location of the appliance.
6 Feet
210.50(C)
Required 125 volt, 15 and 20 ampere receptacles in dwelling units shall not be located higher than ___ feet above the floor.
5.5 Feet(1.7M)
210.52
Required 125 volt, 15 and 20 ampere receptacles in dwelling units shall be installed so that no pint measured horizontally along the floor line of any wall space is more than __ feet from a receptacle outlet.
6 Feet(1.8M)
210.52(A)(1)
Required 125 volt, 15 and 20 ampere receptacles in dwelling units shall be installed in any wall space __ feet or more in width.
2 Feet(600MM)
210.52(A)(2)
A general use receptacle outlet must be provided in any dwelling unit bedroom wall that is at least ___ wide.
2 feet(600MM)
210.52(A)(2)
Unless they are within __ of the wall, receptacle outlets in floors may not be counted as a part of the minimum required number of receptacle outlets.
1.5 Feet(18 In)
210.52(A)(3)
Receptacles installed in a kitchen to serve countertop surfaces shall be supplied by not fewer than ___ small appliance branch circuits.
Two
210.52(B)(3)
A receptacle outlet shall be installed so that no pint along the wall line is more than ___ inches from a receptacle outlet.
24 Inches(600MM)
210.52(C)(1)
Receptacles outlets must be no more than__ above a work surface or countertop.
20 inches(500MM)
210.52(C)(3)
If a receptacle is installed in a countertop, it must__ for such use.
Listed
210.52(C)(3)
Receptacles installed in work surfaces must be listed for:
Work surfaces or countertops
210.52(C)(3)
For dwelling units, at least one receptacle outlet accessible at grade level and not more than __ feet above grade shall be installed at the front and back of each dwelling.
6.5 Feet(2.0M)
210.52(E)(1)
What is the maximum distance a receptacle in a residential garage may be from the floor?
5.5 Feet(1.7M)
210.52(G)(1)
In dwelling units, hallways of __ feet or more in length shall have at least one receptacle.
10 Feet(3.0M)
210.52(H)
What is the minimum number of general purpose receptacles required to be readily accessible when installed in sleeping rooms of dorms, or guest rooms of hotels and motels?
Two
210.60(B)
One receptacle outlet shall be installed at an accessible location for the servicing of heating, air conditioning, and refrigeration within ___ feet and on the same level as the equipment.
25 Feet(7.5M)
210.63
At least one wall switch controlled lighting outlet shall be installed in every __ room, kitchen, laundry area, and bathroom.
Habitable
210.70(A)(1)
For dwelling units and garages, at least one wall switch controlled lighting outlet shall be installed to provide illumination on the ___ side of outdoor entrances of exits with grade level access
Exterior
210.70(A)(2)
Interior stairs shall have switches at each end, where the stairway between floor levels has __ risers or more.
Six
210.70(A)(2)
At least one __ containing a switch or controlled by a walls switch must be installed attics or underfloor spaces containing equipment requiring servicing, such as heating, air conditioning, and refrigeration equipment. One or more pointy of control should be at the normal point of entry for such spaces.
Lighting Outlet
210.70(C)
The calculated load for circuits supplying lighting units that have autotransformers, ballasts, or transformers will be based on:
Total ampere ratings of units and not total watts of the lamps
220.11(B)
The load for an electric sign or outline lighting system should be computed at a minimum of __ volt-amps when sizing the service calculation.
1200
220.14(F)
Loads for convenience receptacle outlets shall be computed at not less than__ volt-amperes for each single or each multiple receptacle on one yoke.
180
220.14(I)
General lighting in dwelling units is required to have a unit load of at least __ VA.
3
220.41
For a dwelling with 2600 square feet of habitable space, what is the required minimum number of 15 ampere, 120 volt, general lighting branch circuits?
5 Lighting Circuits
2600 sq. ft x 3VA=7800 VA (total lighting VA of house)
120V x 15A=1800 VA (one circuit)
7800 VA(load) / 1800 (one circuit)=4.3=5
If they are served by the same feeder or service in a one family, two family, or multifamily dwelling, is is allowable to apply a demand factor of 75% to the nameplate rating load of __ or more appliances fastened in place, other than air conditioning equipment, clothes dryer, electric ranges, or space heating equipment
4
220.53
The load for household electric clothes dryers in a dwelling unit(s) shall be__ watts(volt-amperes) or the nameplate rating, whichever is larger, for each dryer served.
5000
220.54
What is the feeder demand for a 4.40kW electric clothes dryer in a dwelling unit?
5kW
220.54
The branch circuit demand load for one 6kW cooktop and two 3kW ovens in a dwelling unit would be:
8kW
220.55(Note 5 & 6)
Overhead conductors for festoon lighting shall not be smaller than__ AWG unless the conductors are supported by messenger wires.
12 AWG
225.6(B)
When overhead conductors for festoon lighting are in spans more than__ ft., they must be supported by messenger wire. All such conductors may not be less than 12 AWG unless supported by messenger wires.
40 Feet(12M)
225.6(B)
When overhead spans of open conductors and open multiconductor cables of 600 volts or less, nominal, with a voltage of 150 volts to ground or less, pass over sidewalks, or come from any platforms or projection where someone might reach them, and accessible to pedestrians only, the minimum clearance is __ ft.
10 Feet(3.0M)
225.18
What is the minimum clearance in feet for overhead spans of open conductors and open multiconductor cables of 600 volts or less, nominal, over residential property and driveways, and those commercial areas not subject to truck traffic where the voltage does not exceed 300 volts to ground?
12 Feet(3.7M)
225.18
What is the minimum clearance over residential driveways of overhead spans of open conductors of up to 300 volts to ground?
12 Feet(3.7)
225.18
The minimum clearance over residential property and driveways, and those commercial areas not subject to truck traffic where the voltage is over 300 volts to ground is:
15 Feet(4.5M)
225.18
Where overhead spans of open conductors and open multiconductor cables of 600 volts or less, nominal, pass over alleys, driveways on other than residential property, parking areas subject to truck traffic, roads, and other land traversed by vehicles such as cultivated, forest, grazing, and orchard, the clearance must be at least:
18 Feet(5.5M)
225.18
When overhead spans of open conductors and open multiconductor cables pass over a roof, the vertical clearance must be at least__ above the surface. Exceptions ignored.
8.5 Feet(2.6M)
225.19(A)
When overhead spans of open conductors and open multiconductor pass over a roof, the vertical clearance must be maintained for at least __ ft. in all directions from the edge of the roof. Exceptions ignored.
3 Feet(900MM)
225.19(A)
Final Spans to buildings shall be permitted to be attached to the building, but they shall be kept not less than__ feet from windows that are designed to be opened.
3 Feet(900MM)
225.19(D)(1)
Where raceways are on exteriors of buildings or other structures, they must be arranged so they drain, and designated as __ for wet locations.
Suitable for use
225.22
The disconnecting means for a building or structure served, where the conductors p[ass thorough the building or structure, must be installed___, and it must be in a readily accessible location, closest to the point of entrance of the conductors. Exceptions ignored.
Either inside or outside
225.32(B)
The disconnecting means shall be at a __ accessible location nearest the point of entrance of the conductors.
Readily
225.32(B)
There shall be no more than __ disconnects per supply grouped in any one location.
Six
225.33
Each disconnect shall be marked to indicate the __ served.
Load
225.34
In a multiple occupancy building, each occupant shall have __ to the occupants supply disconnecting means.
Access
225.35
When there are a combination of branch circuits, feeders, or services for a building or structure__ there must be a directory or permanent plaque installed at each branch circuit disconnection location and feeder, showing other branch circuits, feeders, and services supplying the building or structure or passing through it, and what area is served by each one
Passing through it or supplying it
225.37
For a one family dwelling, the feeder disconnecting means shall have a rating of not less than__ amperes, 3-wire.
100
225.39(C)
When conductors are installed under at least __ in. of concrete beneath a building or other structure, they shall be considered outside of a building or other structure.
2
230.6
When conductors are installed within a building or other structure in a raceway that is encased in concrete or brick at least __ in. think, they shall be considered outside of a building or other structure.
2 Inches (50MM)
230.6
Conductors other than service conductors shall not be __ in the same service raceway or service cable.
Installed
230.7
Generally, service conductors installed as open conductors must have a minimum clearance of __ from balconies, doors, porches, and windows that are designed to be opened.
3 Feet(900MM)
230.9(A)
Overhead service drop conductors shall have a vertical clearance of not less than __ feet above the roof surface.
8.5 Feet(2.6M)
230.24(A)
What is the minimum vertical clearance from final grade for open overhead service conductors up to 1000 volts over public driveways?
12 Feet(3.7M)
230.24(B)
Service entrance cables shall be supported at intervals not exceeding __ inches.
30 Inches(750MM)
230.51(A)
Service entrance cables shall be supported by straps or other approved means within __ inches of every service head, gooseneck, or connection to a raceway or enclosure.
12 Inches(300MM)
230.51(A)
Service entrance cables must be equipped with a __ listed for use in wet locations.
Service Head
230.54(B)
Service disconnecting means shall not be installed in___.
Bathrooms
230.70(A)(2)
What is the minimum rating for a service disconnecting means when supplied with a 120/240 volt, 3-wire, single phase service for a one family dwelling?
100 Amperes
230.79(C)
Conductors must be protected against overcurrent in accordance with their ampacities, except for:
Flexible cords, flexible cables, and fixture wires
240.4
310.14
Overcurrent devices are designed to open all conductors of a circuit, including a grounded conductor, so that no pole can operate__, so other than overload protection no overcurrent device may be connected in series with any conductor that has been intentionally grounded.
Independently
240.22
Overcurrent devices must be readily accessible and installed so the center of the operating handle grip of the circuit breaker or switch, when in its highest position, is___ above the floor or working platform, or less. Exceptions ignored.
6 Feet 7 Inches(2.0M)
240.24(A)
What dwelling unit area are panelboards NOT allowed to be located in?
Bathrooms
240.24(E)
Plug fuses of the Edison base type shall be classified at not over 125 volts and __ amperes and below.
30 Amperes
240.51(A)
Which of the following is only for replacements in existing installations and is NOT allowed in new installations?
Class H renewable cartridge
240.60(D)
Circuit breakers used as__ in 120 volt and 277 volt fluorescent lighting circuits shall be listed and shall be marked SWD or HID.
Switches
240.83(D)
Electrical Systems that are__ shall be connected to earth in a manner that will limit the voltage imposed by lighting, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operations.
Grounded
250.4(A)(1)
Normally non-current-carrying conductive materials enclosing electrical conductors or equipment shall be connected together, and to the electrical supply source, in a manner that establishes an effective__ current path.
Ground-Fault
250.4(A)(3)
