Master Electrician
Where a 20-ampere rated branch circuit supplies three (3), 15-ampere, 125 volt receptacle outlets, in compliance with the NEC®, the MAXIMUM load, in amperes, any one receptacle outlet is permitted to carry is _____.
12 amperes
A thermal barrier shall be required if the space between the resistors and reactors, of 600 volts or less, and combustible material is LESS than _____.
12 inches
When an equipment room houses electrical equipment rated at LEAST _____ or more, the personnel doors intended for entrance to and egress from the working space, shall open in the direction of egress.
1200 amperes
The branch circuit conductors supplying one or more units of information technology equipment shall have an ampacity of NOT less than _____ of the connected load.
125 percent
What is the MAXIMUM distance between supports for straight horizontal runs of trade size 1½ in. threaded rigid metal conduit (RMC)?
14 feet
Where a listed packaged spa or hot tub is installed outdoors, the unit is permitted to be cord-and-plug connected, provided the cord is NOT longer than _____ and protected by a GFCI.
15 feet
A recreational vehicle campground has one hundred-fifty (150) campsites provided with electrical power. Twenty-five (25) of the campsites are reserved as tent sites. How many of the sites are required to have a 20-ampere, 125-volt receptacles provided?
150
The MINIMUM committed burial depth for conduit or cables installed under an airport runway, concourse or tarmac is _____
1½ feet
When an electrical service is required to have a grounded conductor present, what is the smallest grounded conductor permitted for an electric service using size 1000 kcmil copper ungrounded (phase) conductors?
2/0 AWG copper
What is the MINIMUM size 75º C copper service-entrance conductors required for a 200 ampere rated commercial service? Assume ambient temperature and the number of current-carrying conductors in the raceway is not a consideration.
3/0 AWG THW
The MAXIMUM allowable ampacity of a size 750 kcmil XHHW aluminum conductor where there are six (6) current-carrying conductors in the raceway, installed in a dry location, where the ambient temperature will reach 22 deg. C is _____ .
361.92 amperes
Where a commercial building has a 600 ampere, 3-phase, 208Y/120 volt service supplied with two (2) parallel sets of size 350 kcmil copper conductors installed in separate raceways, determine the MINIMUM size aluminum grounding electrode conductor permitted to the metal water piping system used as the grounding electrode.
4/0 AWG
What is the MAXIMUM load, in VA, the branch-circuit conductors of a 20-ampere, 277-volt circuit are permitted to carry when supplying a continuous lighting load? Consider the overcurrent protection device protecting the branch circuit is not listed for operation at 100% of its rating.
4432 VA
For other than one-family dwellings, an emergency disconnect switch must be provided for spas and hot tubs NOT less than ____ away from the spa or hot tub and must be readily accessible to the users.
5 feet
In an aircraft hanger, the area that extends upward from the floor level _____ above the upper surface of aircraft wings, power plants and fuel tanks shall be classified as a Class I, Division 2 or Zone 2 location.
5 feet
What is the MAXIMUM distance allowed to support intermediate metal conduit (IMC) from a junction box, where structural members do not readily permit fastening?
5 feet
What is the MAXIMUM distance permitted between supports for straight horizontal runs of trade size 1½ in. PVC conduit?
5 feet
Where a hotel has a stationary electric sign installed inside a decorative fountain, the sign shall be at LEAST _____ inside the fountain, when measuring from the outside edges of the fountain.
5 feet
All 240-volt, twist-lock, 30-ampere receptacles on a construction site where supplied from a temporary service, are required to be provided with _____when not covered by an assured grounding program.
GFCI protection
Cabinets containing overcurrent protective devices shall NOT be located _____.
over steps of a stairway
An aluminum grounding electrode shall be _____.
prohibited
Conductors leading to a gasoline motor fuel dispensing pump shall be _____.
provided with a switch
When combination surface nonmetallic raceways are used both for signaling and for power and lighting circuits, the different systems shall be _____.
run in separate compartments
All 15- and 20-ampere, 125- and 250-volt, nonlocking receptacles installed in a wet location shall be listed _____ type.
weather-resistant
Type AC cable shall NOT be used _____.
where embedded in plaster in wet locations
AFCI protection is required for all 15- and 20-ampere, 120-volt branch-circuits supplying outlets located in _____.
guest rooms and guest suites of hotels and motels that are provided with permanent provisions for cooking
Flexible cord is permitted to be connected to fluorescent luminaires where the cord _____.
is visible its entire length
All metallic switchgear rated for over 600 volts shall be provided with a grounding busbar for the purpose of connecting the _____.
metallic shield of cables
When calculating the total load of an office building, and the number of general-purpose receptacles to be installed is not yet determined, an additional load of _____ volt-amp(s) per square foot is required for the receptacle outlets.
one
In general, what is the largest size transformer, in kVA, that may be installed in an area or room that is NOT constructed in a fire-resistant manner?
112 1/2 KVA
Where electrical metallic tubing (EMT) is installed under metal-corrugated sheet roofing decking, a clearance of at LEAST _____ must be maintained between the top of the tubing and the surface of the roof decking.
1 1/2 in.
What is the MINIMUM size equipment bonding jumper allowed for receptacles connected to a 20-ampere branch circuit in a critical care area of a hospital?
10 AWG
When connecting utilization equipment to a 20-ampere rated branch-circuit that also serves luminaires (lighting fixtures), the utilization equipment shall have an ampere rating of NOT more than _____.
10 amperes
Apply the general method of calculation for dwellings and determine the demand load, in kW, on the ungrounded service-entrance conductors for one (1) 18 kW residential electric range.
10.4 kW
In general, if a cablebus system is rated 95 amperes, the MAXIMUM allowable rating of the overcurrent device used to protect the cablebus is _____.
100 amperes
The NEC permits trade size 3/8 in. flexible metal conduit (FMC) to be used to enclose tap conductors for luminaires, provided the length of the FMC does NOT exceed _____ .
6 feet
An inverse time circuit breaker used as the disconnecting means for a 50 hp, 480-volt, three-phase continuous-duty, induction-type ac motor shall have an ampere rating of at LEAST _____.
75 amperes
After applying all demand factors, the ampacity of the service-entrance conductors are required to be NOT less than _____ where both the overcurrent device and its assembly are not listed for operation at 100 percent of their rating.
the sum of the noncontinuous loads plus 125 percent of the continuous loads
Luminaires located over an indoor installed hot tub and protected by a ground-fault circuit-interrupter shall be installed at a MINIMUM height of _____.
7½ ft.
Conductors supplying outlets for arc and xenon motion picture projectors of the professional type shall be a MINIMUM size of _____.
8 AWG
Where a conductor is marked RHW-2 on the insulation what does the "-2" represent?
The conductor has a maximum operating temperate of 90 degrees C.
Wiring methods associated with solar photovoltaic (PV) systems shall not be installed within _____ of the roof decking or sheathing except where directly below the roof surface covered by PV modules and associated equipment.
10 inches
An emergency system is required to have NO more than _____ to have power available in the event of failure of the normal electrical supply system.
10 seconds
Where a 90 ampere, 240-volt, single-phase load is located 225 feet from a panelboard and is supplied with size 3 AWG copper conductors, determine the approximate voltage drop on the conductors. (K = 12.9)
10 volts
Where a motor of more than 1 horsepower has a temperature rise of 50 deg. C indicated on the nameplate, for the purpose of selecting the overload device, this device shall be selected to trip at NO more than _____ of the motor's full-load ampere rating. (No exceptions or modifications permitted.)
115 percent
Determine the MAXIMUM permitted operational setting of an adjustable inverse time circuit breaker used for branch-circuit, short-circuit and ground-fault protection of a 15 hp, 208-volt, three-phase, squirrel cage, Design B, continuous-duty ac motor. Assume the rating you select will be sufficient for the starting current of the motor and exceptions need not be applied.
115.5 amperes
A 50 kVA transformer with a 480-volt, 3-phase, primary and a 208Y/120 volt, 3-phase secondary is to be installed. Overcurrent protection is required on both primary and secondary sides of the transformer. Determine the MAXIMUM standard size overcurrent protection device permitted on the primary side.
150 amperes
The ampacity of size 1/0 AWG THWN/THHN, dual-rated copper conductors enclosed in rigid metal conduit (RMC) when installed underground in direct contact with the earth is _____ .
150 amperes
A commercial building is to be supplied with a transformer having a 480Y/277 volt, 3-phase primary and a 208Y/120 volt, 3-phase secondary. The secondary will have a balanced computed demand load of 416 amperes per phase. The transformer is required to have a MINIMUM kVA rating of _____ .
150 kVA
An outdoor motor fuel gasoline dispensing pump is considered to be a Class I, Division 2 hazardous location up to _____ above grade level within _____ horizontally from any edge of the motor fuel pump enclosure.
18 inches - 10 feet
A 150 kVA service transformer has a 480Y/277 volt 3-phase primary and a 208Y/120 volt, 3-phase secondary. What is the approximate full-load ampere rating of the primary of the transformer?
180 amperes
Where rigid polyvinyl chloride (PVC) conduit is installed underground to supply a gasoline dispensing unit, threaded rigid metal conduit (RMC) or threaded intermediate metal conduit (IMC) shall be used for the LAST _____ of the underground run to where the conduit emerges.
2 feet
What percent of electrical supplied RV spaces in a recreational vehicle park must have 50-ampere, 125/250-volt receptacle outlets provided?
20 percent
What is the MINIMUM bend radius of trade size 4 in. rigid metal conduit (RMC) where the bend is not made with a one-shot or full-shoe bender?
24 inches
Where a rigid metal conduit (RMC), containing conductors rated less than 600 volts, cross under a public driveway at a retail shopping center, the RMC is required to be buried at a MINIMUM depth of _____.
24 inches
For lighting systems operating at 30-volts or less, the output circuits of the power supply are to be rated for NOT more than _____.
25 amperes
A motel to be constructed will have two (2), 20-ampere, 120-volt branch circuits provided for the exterior electric signs. Determine the demand load, in VA, for the electric signs, on the feeder and service-entrance conductors.
3,000 VA
What is the MINIMUM size copper common grounding electrode conductor required to run through a building to four (4) separately derived systems (transformers) each having size 3/0 AWG copper secondary conductors?
3/0 AWG
X-ray equipment installed in a hospital may be served by a hard service cord with a suitable plug provided the branch-circuit rating does NOT exceed _____.
30 amperes
In general, direct-buried cables of 13,000 volts must be buried at a depth of NOT less than _____.
30 inches
Communications wires and cables shall have a voltage rating of NOT less than _____.
300 volts
Unless approved for a higher voltage, surface nonmetallic raceways are NOT permitted where the voltage is _____ or more between conductors.
300 volts
A twenty-five (25) ft. long tap conductor tapped from a 100 ampere rated feeder conductor, shall have an ampacity of NOT less than _____.
33.3 amperes
The overall length of a power-supply cord to mobile home is required to be NOT more than _____.
36 1/2 feet
Using the standard method of calculation, what is the demand, in kW, on the ungrounded (line) service-entrance conductors of an apartment complex that has thirty-five (35) electric ranges rated at 11.5 kW each?
50 kW
After all demand factors have been taken into consideration for an office building, the demand load is determined to be 90,000 VA. Where the building has a 120/240 volt, single-phase electrical system, what MINIMUM size copper conductors with THHW insulation are required for the underground installed ungrounded (phase) service-lateral conductors?
500 kcmil
Two (2) or more motors may be installed without individual overcurrent protection devices if rated less than 1 hp each, and the full-load current rating of each motor does NOT exceed _____ if they are on a 120-volt, 20-ampere branch circuit.
6 amperes
Liquid-tight flexible metal conduit (LFMC) is approved for use as an equipment grounding conductor if it does NOT exceed _____ in length.
6 feet
When rigid polyvinyl chloride conduit (PVC) is used to enclose conductors feeding a wet-niche luminaire in a permanently installed swimming pool, a _____ insulated copper grounding conductor shall be installed in this conduit, unless a listed low-voltage lighting system not requiring grounding is used.
8 AWG
Luminaires shall be installed so that the adjacent combustible material is not subjected to temperatures in excess of _____.
90 degrees C
A fifteen (15) ft. horizontal run of rigid metal conduit (RMC) is to be installed between two enclosures located in a Class II, Division 1 hazardous location. One enclosure is dust ignition-proof; the other is not. The NEC® requires a MINIMUM of _____ sealing fittings.
None required
Conductors other than service-entrance conductors shall be permitted to be installed in a cable tray with service-entrance conductors provided _____ .
a solid fixed barrier of material compatible with the cable tray is installed to separate the systems
Where portions of a cable, raceway or sleeve are known to be subjected to different temperatures and where condensation is known to be a problem, the raceway or sleeve shall _____.
be filled with an approved material
Disregarding exceptions, bonding between Class I locations and the point of grounding for service equipment may be done by _____.
bonding jumpers
Where a central vacuum assembly is located in a storage closet adjacent to the laundry room of a dwelling, accessible non-current-carrying metal parts of the assembly shall be ____.
connected to an equipment grounding conductor
The accessible portion of abandoned supply circuits and interconnecting cables located in an information technology equipment room shall be removed, UNLESS _____.
contained in a raceway
Fixed outdoor electric deicing equipment shall be considered as a _____ load.
continuous
Overcurrent protection of transformers, of 600 volts or less, is required to be sized _____.
in accordance with Table 450.3(B)
In movie theaters, all switches for controlling the emergency lighting systems shall be located _____.
in the lobby
Where a service riser is installed in a wet location and contains THWN insulated conductors, the wiring method used _____.
is permitted to be electrical metallic tubing (EMT)
Conductors tapped from a feeder and supplying the primary of a transformer need not have overcurrent protection, where the length of the tap conductors are not over 25 feet and have an ampacity of at LEAST _____ of the rating of the overcurrent device protecting the feeder conductors.
one-third
Electrical equipment such as switchboards, panelboards, industrial control panels, and motor control centers, located in commercial and industrial occupancies are required to be field marked to warn _____ of potential electrical arc flash hazards.
qualified persons
For a grounded electrical system supplied by a feeder or branch circuit, the equipment grounding conductor shall be sized in accordance with _____.
the overcurrent protective device
A panelboard is limited to 42 overcurrent protective devices where _____.
the panelboard is a "split-bus" type panelboard
Battery back-up exit lighting shall receive power from _____.
the same branch circuit serving the normal lighting in the area
