Hoja de Referencia del Examen · Referencia Rápida

North Carolina Intermediate Electrical Contractor (I)

North Carolina  ·  PSI Services Contractor

Verificado, no estimado. Cada cifra a continuación proviene de la estructura oficial del examen que mantenemos: número de preguntas, puntaje de aprobación y ponderación de temas. Las preguntas de práctica están fundamentadas en la ley fuente con citas de estatutos. Omitimos cualquier cifra que no podamos verificar en lugar de adivinarla.
Total de preguntas
100
Puntaje de aprobación
70%
Tiempo del examen
360 min
Administrado por
PSI Services Contractor
Formato
Se permiten materiales de referencia

Porción Estatal de North Carolina 100 preguntas

Unión y Puesta a Tierra 11 Q · 11%
Systems and equipment requiring grounding and ground-fault protectionLocation of connection and required interconnectionsConductor identification and color codingBonding jumpersGrounding electrode conductorsEquipment grounding conductorsGrounding electrodesLow-voltage specificationsHigh-voltage specificationsBonding conductor connectionsBonding/bonding gridTermination
Protección contra Sobrecorriente 9 Q · 9%
Location in circuitSizing requirementsCircuit breakersPlug and cartridge fusesEnclosures and locationsHigh-voltage
Métodos de Cableado y Terminaciones 10 Q · 10%
Permitted applications and usagesCharacteristicsConduit and wireway fillPermitted applications and usagesCharacteristicsProtection from damageTraveling cables and controlsPermitted usages and ampacity ratingsCharacteristicsMiscellaneousOutdoorsSwitchboards, panelboards, switches, and cabinets +2 más
Cajas y Accesorios 7 Q · 7%
General informationSizing requirements
Acometida y Equipos 9 Q · 9%
Installation requirementsService equipmentGeneral sizing requirements
Motores y Cableado de Control 8 Q · 8%
General informationBranch circuit and feeder ampacityOverload protectionShort-circuit and ground-fault protectionDisconnects/controllersSizeTypeLocationSeparation of conductors
Ocupaciones Especiales y Lugares Peligrosos 9 Q · 9%
Emergency systemsHealth care facilitiesMobile homes and mobile home parksPlaces of assembly, theaters, and similar locationsSwimming poolsUnderwater lighting fixturesGeneral requirementsBulk storage plantsFinishing processesGas stations and commercial garages
Cálculos de Carga 11 Q · 11%
Branch circuitsTotal computed loadConductor ampacity requirementsLow-voltageHigh-voltage
Electrodomésticos, Equipos e Iluminación 7 Q · 7%
Air conditionersResidential, commercial, and industrial equipmentLighting fixturesSpace heating equipment and boilersTransformersMachine room
General 3 Q · 3%
DefinitionsInstallation requirements
Leyes, Reglamentos, Prácticas Comerciales Básicas y Aplicaciones Prácticas 16 Q · 16%
Electrical Contractors Licensing Law (General Statutes Chapter 87, Article 4)Board’s Rules for the Implementation of the Electrical Contractors Licensing Law (Title 21, North Carolina Administrative Code, Chapter 18B)NASCLA Contractors’ Guide to Business, Law and Project Management - North Carolina Electrical EditionLighting and Power Plans; Estimating and General KnowledgeNational Fire Alarm Code

Distinciones Clave

NEC 250.22 (prohibited grounding)vsNEC 250.21(A) (permitted ungrounded)

250.22 absolutely prohibits grounding certain circuits (e.g., crane circuits over combustible fibers in Class III locations), while 250.21(A) lists systems that are merely permitted but not required to be grounded.

NEC Handbook, Sections 250.22 and 250.21(A)
Supervised Industrial Installation conductor ampacity (240.91(B))vsStandard installation conductor ampacity (240.4(C))

In a supervised industrial installation with an overcurrent device rated over 800 A, conductor ampacity may be as low as 95% of the device rating; in all other installations the conductor ampacity must equal or exceed 100% of the device rating.

NEC, Section 240.91(B)
Grounding electrode conductor connected at transformervsGrounding electrode conductor connected at first disconnecting means

For a separately derived system, the grounding electrode conductor must be connected at the same point where the system bonding jumper is connected—whether that is at the transformer or at the first system disconnecting means.

NEC, Section 250.30(A)(5)
Branch-circuit inverse time circuit breaker (as motor controller)vsInstantaneous-trip breaker (as motor controller)

An inverse time circuit breaker rated in amperes may serve as a controller for ALL motors under 430.83(A)(2), whereas an instantaneous-trip breaker may only be used as a controller if it is adjustable and part of a listed combination motor controller.

NEC, Section 430.83(A)(2)
Guest rooms WITHOUT permanent cooking provisions (overcurrent device access)vsGuest rooms WITH permanent cooking provisions (overcurrent device access)

Under NEC 240.24(B)(2), in hotels where management provides continuous electrical supervision, overcurrent devices for guest rooms without permanent cooking provisions may be accessible only to management; rooms with permanent cooking provisions do not qualify for this allowance.

NEC Handbook, Section 240.24(B)(2)
Field-marking grounded conductors 4 AWG or largervsFactory-identified grounded conductors 6 AWG and smaller

Conductors 4 AWG or larger may be field-identified at terminations with a distinctive white or gray marking per NEC 200.6(B)(4), while conductors 6 AWG and smaller must use factory-applied white/gray finish or stripes per 200.6(A).

NEC, Section 200.6(B)(4)
Cost-plus contractvsLump-sum contract

Under a cost-plus contract the owner reimburses all actual labor and material costs plus a markup fee, so the owner bears cost-overrun risk; under a lump-sum contract the contractor agrees to a fixed price and absorbs all risk including unforeseen cost overruns.

NASCLA Contractors Guide, Contract Management chapter — Cost-Plus Contract section
MediationvsCollaborative law

In mediation an independent neutral third party facilitates dialogue while the disputing parties themselves set the terms of any agreement; in collaborative law the parties use their own advocates (typically lawyers) to negotiate a mutually beneficial result with no neutral mediator or arbitrator.

NASCLA Contractors Guide, Contract Management chapter — Alternative Dispute Resolution section
Performance bondvsPayment bond

A performance bond guarantees the contractor will complete the contract within its time frame and conditions, whereas a payment bond guarantees that subcontractors and suppliers will be paid for work properly performed.

NASCLA Contractors Guide, Managing Risk chapter — Types of Bonds section
C CorporationvsS Corporation

A C Corporation faces double taxation (corporate profits taxed, then dividends taxed again to shareholders), while an S Corporation avoids double taxation but is limited to no more than 100 shareholders who are U.S. citizens or legal residents.

NASCLA Contractors Guide, Choosing Your Business Structure chapter — C Corporations section
Bar chart schedulingvsCalendar scheduling

Both methods fail to show interdependencies between activities, but calendar scheduling's primary advantage is the ability to link tasks to specific dates such as delivery dates, payment schedules, and holidays, making it better suited to smaller, less complex projects.

NASCLA Contractors Guide, Scheduling and Project Management chapter — Bar Chart Scheduling section
Room AC cord at 120 VvsRoom AC cord at 208/240 V

Per NEC 440.64, a flexible supply cord for a 120-volt room air conditioner may not exceed 3.0 m (10 ft), while a cord for a 208- or 240-volt unit may not exceed 1.8 m (6 ft).

NEC, Section 440.64

Términos Clave

Prohibited-from-grounding circuits (NEC 250.22) NEC Handbook, Sections 250.22 and 250.21(A)
NEC 250.22 absolutely forbids grounding certain circuits, including electric crane circuits operating over combustible fibers in Class III locations.
System bonding jumper connection point (NEC 250.30(A)(5)) NEC, Section 250.30(A)(5)
NEC 250.30(A)(5) requires the grounding electrode conductor of a single separately derived system to be connected at the exact point where the system bonding jumper connects.
Acceptable grounding/bonding connections (NEC 250.8) NEC, Section 250.8(A) and (B)
NEC 250.8(A) lists permitted methods for connecting grounding electrode conductors and bonding jumpers; 250.8(B) expressly prohibits connections that depend solely on solder.
Grounded conductor routing in AC systems (NEC 250.24(C)) NEC, Section 250.24(C)
NEC 250.24(C) requires that in a grounded AC system of 1000 V or less, the grounded conductor be routed with the ungrounded conductors to each service disconnecting means and connected to its grounded conductor terminal or bus.
One-family dwelling service disconnecting means rating (NEC 230.79(C)) NEC, Section 230.79(C)
NEC 230.79(C) requires the service disconnecting means for a one-family dwelling to be rated not less than 100 amperes, 3-wire.
Hermetic refrigerant motor-compressor branch-circuit conductor ampacity (NEC 440.32) NEC, Section 440.32
NEC 440.32 requires branch-circuit conductors for a single motor-compressor to have an ampacity not less than 125% of the motor-compressor rated-load current.
Hermetic motor-compressor overcurrent device maximum rating (NEC 440.22(A)) NEC, Section 440.22(A)
NEC 440.22(A) sets the protective device maximum at 175% of rated-load current, or up to 225% when the 175% rating is insufficient for starting current.
Machine screw thread engagement for bonding (NEC 250.8(A)(5)) NEC, Section 250.8(A)(5)
NEC 250.8(A)(5) requires a machine screw-type fastener used to terminate a bonding jumper to engage not less than two threads, or be secured with a nut.
Continuous load NEC Article 100 — Definitions (edition-independent)
A load whose maximum current is expected to continue for 3 hours or more; conductors and overcurrent devices serving continuous loads are generally sized at 125% of the load.
Labor burden NASCLA Contractors Guide, Bidding and Estimating chapter — Labor Burden section
The additional employer costs (employment taxes, insurance, etc.) added to base labor cost, approximating 30% of that cost.
Bid peddling NASCLA Contractors Guide, Bidding and Estimating chapter — Bid Peddling section
An unethical practice where a losing subcontractor approaches the general contractor after contract award and offers to undercut the winning subcontractor's price.
Working capital NASCLA Contractors Guide, Financial Management chapter — Balance Sheet section
A liquidity measure calculated as Current Assets minus Current Liabilities.
Watt Basic electrical theory — units of measurement
The unit used to measure electrical power, i.e., the rate at which electrical energy is used or produced.
kcmil Conductor sizing units (kcmil)
A conductor size unit equal to 1,000 circular mils; used for conductors larger than 4/0 AWG.
Punch list NASCLA Contractors Guide, Scheduling and Project Management chapter — Job Completion and Closeout section
A document developed during the post-completion walkthrough that records remaining work items or corrections required before a project is formally closed out.
OSHA fatality reporting deadline NASCLA Contractors Guide, Jobsite Safety and Environmental Factors chapter — OSHA Recordkeeping section
Employers must orally report any work-related fatality to the nearest OSHA Area Office within 8 hours of its occurrence.

Fórmulas que Debes Saber

Branch-circuit conductor ampacity — single motor-compressor (hermetic)Minimum ampacity = Rated-load current × 1.25
Branch-circuit conductor ampacity — supervised industrial installation (>800 A device)Minimum ampacity = Overcurrent device rating × 0.95
Standard conductor ampacity vs. overcurrent device ratingMinimum conductor ampacity ≥ 100% of overcurrent device rating
Conduit fill area — two conductors (31% fill column)Required conduit area = Number of conductors × Individual conductor area; select conduit whose 31%-fill area ≥ result
Power (Watts) from horsepowerWatts = Horsepower × 746
Net employee payNet pay = Gross pay − (Federal income tax + Social Security tax + Medicare tax + State income tax + Other deductions)
Working capitalWorking capital = Current assets − Current liabilities
Labor cost with burdenTotal labor cost = Base labor cost × 1.30
Bid markupBid price = Total cost × (1 + markup rate); standard industry markup = 15%