Electrical: NEC Level 4, Entire First Semester

Electrical equipment and wiring methods in or on portable structures for carnival or circuses shall have mechanical protection where subject to ____.

physical damage

NEC Article 518 contains _____.

requirements for places of assembly

Line isolation monitors must have a green signal lamp that glows when the system is isolated from ground and located _____.

so it is visible to staff in the anesthetizing location

When making service calculations for multi-family dwellings, additional demand factors must be applied to the portion of the neutral load greater than _____.

200A

What is the adjusted ampacity for each of six No. 4/0 THHN copper current-carrying conductors in a single conduit? (Given: the ampacity of 4/0 THHN is 260A.)

208A 260A x 80% = 208A

When used in a circuit, an LED is generally operated at about _____.

20mA or less

GFCI protection is required for 15A, 20A, and 30A 125V and 125V/250V receptacles that are part of a portable generator used for temporary wiring rated not greater than ____.

15kw

If a store lighting load is 14,000VA (continuous), which of the following must be used for the circuit calculation?

17,500VA 1.25 x 14,000VA = 17,500VA

In Class I, Division 1 locations, conduit seals shall be installed within __ in. from the enclosure or as required by the enclosure marking.

18

The demand lighting load for a 20,000 ft2 motel with no dining room or ballroom is _____.

18,000VA Demand lighting load = 2VA/ft2 x 20,000VA = 40,000VA First 20,000 VA x 50% = 10,000VANext 20,000 VA x 40% = 8,000 VA Total Load = 18,000VA

In assembly occupancies of fire-rated construction, nonmetallic raceways encased in not less than ____ in. of concrete shall be permitted.

2

In commercial garages, Type PVC conduit, Type RTRC conduit and Type HDPE conduit shall be permitted where buried under not less than ____ ft of cover.

2

Refer to Figure 1. What is the total load a feeder serving four 2hp motors, three 5hp motors, one 15hp motor, and one 25hp motor? All motors are 208V.

219.8A

What is the feeder ampacity for a three-phase, 120/208V subpanel with a connected load of 84,563VA?

235A I = VA ÷ (V x √3) = 84,563VA ÷ (208V x 1.732) = 235A

In a medical facility, receptacles should be mounted _____.

24" (600 mm) above the floor

What is the load for 40 non-dwelling unit receptacles? (Assume that the load is not continuous.)

7,200VA 180VA per receptacle x 40 receptacles = 7,200VA

Which of the following supplies power to the areas that are directly related to patient care, including emergency rooms and pharmacies?

Critical Branch

Which part of an EES supplies power to major electrical equipment that is not directly related to patient care?

Equipment Branch

In Class I. Division 1 locations, all utilization equipment shall be ____ for the use in a Class I, Division 1 location.

Identified

In addition to the NEC®, emergency electrical power for hospitals is governed by the _____.

Joint Commission

Optional standby systems are covered in _____.

NEC Article 702

An optional method for determining feeder to schools is covered in _____.

NEC Section 220.86

The figure above shows the electrical symbol for a(n) _____.

NPN transistor: Collector \ /^Emitter | Base

When the overcurrent protection for a conductor is located on the load end rather than the supply side of a conductor it is considered to be a(n) _____.

tap conductor

Hospital-grade receptacles are _____.

tested for superior mechanical strength

Transfer switches are sized based on ____.

the calculated continuous current

In marinas, boatyards, and commercial and noncommercial docking facilities, the bottom of enclosures for transformers shall not be located below ____.

the electrical datum plane

The difference between an N-channel and a P-channel JFET is _____.

the polarity of the voltage

A storage battery must supply at least what percentage of the system voltage for the total load of circuits supplying legally required standby power?

87.5%

Health care facilities that do not require a Type 1 or Type 2 EES may use batteries for emergency power provided that they maintain 87-1/2 percent of their voltage under full load for a period of _____.

90 Minutes

Wiring methods and materials permitted in Class 1, Division 1 locations include _____.

All of these: threaded rigid metal or threaded steel IMC flexible fittings listed for Class I, Division 1 locations boxes approved for Class I, Division 1 locations

Equipment shall be identified not only for the class of hazardous (classified) location, but also for the explosive, combustible, or ignitable properties of the specific ____ present.

Any of these: Fibers/Flyings Gas or Vapor Dust

Attachment plugs and receptacles in hazardous locations must be listed for use in _____.

Class I, Group C locations

Which of the following commercial loads can be fed from a regular circuit rather than an emergency circuit?

Computer equipment

Installation of X-ray equipment is governed by _____.

NEC Article 517, Part V

The rules governing the design of circuits supplying power to boats is covered in _____.

NEC Article 555

A transistor is made by joining how many layers of semiconductor material?

Three

Any facility that admits patients on electrical life support equipment must have a _____.

Type 1 EES

Which of the following statements is true about Type MC cable in patient care spaces?

Type MC cable with a health care facility rating must be used.

The most common method of cooling standby generator sets is _____.

a mounted radiator with an engine-driven fan

Temporary wiring methods shall be acceptable only if ____, based on the conditions of use and any special requirements of the temporary installation.

approved

Flexible cords used in Class II, Division 1 or 2 locations shall _____, except as permitted for pendant luminaires.

be listed for extra-hard usage

In the figure above, the lead marked C is the transistor _____.

collector

Overcharging a lead-acid battery will _____.

destroy the positive plate

In a Class III location, pendant luminaires suspended by stems longer than __ft shall be provided with a fitting or flexible connector identified for the location, or shall be provided with effective bracing.

1

Mobile home and manufactured home feeder circuit conductors shall have a capacity not less than ____.

100A

Low-voltage equipment that is typically in contact with patients must be moisture-resistant and operate on _____.

10V or less

A farm has three buildings with loads of 82A, 65A and 15A. What is the total demand load? Assume that there are no dwellings or motors, and each building is an independent single load.

117A (82A x 1) + (60A x 0.5) + [(5A +15A) x 0.25] = 82A + 30A + 5A = 117A

Using the VA/linear foot method, the total VA that must be used in a service calculation for a 50' show window is _____.

12,500VA 200VA per linear foot x 50' = 10,000VA 10,000VA x 1.25 = 12,500VA

The minimum ampacity for a feeder supplying ten 30A shore power receptacles in a marina is _____.

120A 10 x 30A x 120V = 36,000VA 36,000VA x 0.8 = 28,800VA 28,000VA ÷ 240V = 120A

The nominal open circuit voltage of a lead-acid cell is _____.

2.0V

Refer to Figure 1. What is the total load of a feeder serving four 230V motors rated 5hp, 15hp, 20hp, and 40hp?

241.2A 125% of the largest motor's FLA from NEC Table 430.250: 40hp = 1.25 x 104A = 130A Add this amperage to the other loads: 15.2A + 42A + 54A + 130A = 241.2A

The cross-sectional area of the conductors or optical fiber tubes permitted in a sealing fitting shall not exceed ____ percent of the cross-sectional area of RMC of the same trade size.

25

What is the park electrical wiring system load, after applying the demand factors, for a mobile home park having six mobile homes?

27,840 VA 550.31(A) and Table 550.31 16,000 VA x 6 = 96,000 VA 96,000 VA x 0.29 = 27,840 VA

Before it is considered a continuous load, a load must operate for at least how many hours without interruption?

3

NEC Table 220.12 requires a minimum general lighting load for office buildings to be based on _____.

3-1/2 VA/ft2

The disconnecting means for a shore power connection shall be not more than ____ in. from the receptacle it controls.

30

The smallest size locking and grounding type receptacle that may be used to provide shore power for boats is _____

30A

Use of the 100' tap rule is limited to installation in high-bay manufacturing buildings with wall heights over _____.

35 feet

Operating rooms must be provided with a minimum of _____.

36 receptacles

Which of the following lighting loads would be used in a residence that is 1,650 ft2?

4,950VA 1,650 x 3VA per square foot = 4,950VA

The interior lighting load for a school building with 175,000 square feet of floor space is _____.

525,000VA 175,000 ft2 x 3VA/ft2 = 525,000VA

Each portable structure at a carnival, circus, or fair shall be provided with a means to disconnect it from all ungrounded conductors within sight of and within __ ft of the operator's station.

6

Individual branch circuits are not required for portable X-ray equipment requiring no more than _____.

60A

When performing load calculations for farm buildings, the load that must be included in the calculation at 100% demand must be at least _____.

60A

A commercial kitchen with more than six pieces of kitchen equipment is subject to a demand factor of _____.

65%

What is the demand factor allowed by the NEC® for calculating the neutral conductor size for an electric range load?

70%

Which type of engine-driven AC generator is commonly used as a standby system because they have a longer life and require less maintenance?

Diesel-powered

A No. 1 isolated conductor must be identified using which of the following colors?

Orange

When calculating the service requirement for a particular building, the first step is to _____.

determine the floor area of the building

All areas designated as hazardous (classified) locations shall be properly _____ and shall be available to those authorized to design, install, inspect, maintain, or operate electrical equipment at these locations

documented

A building or portions of a building where engine overhauls, painting, body and fender work, and repairs the require ___ of the motor vehicle fuel tank are performed defines the term "Major Repair Garage."

draining

In Class II, Division 2 locations, enclosures for fuses, switches, circuit breakers, and motor controllers, including pushbuttons, relays, and similar devices shall be ____.

dusttight or otherwise identified for the location

Each general care (category 2) space patient bed location shall be provided with a minimum of ____ receptacle(s), which can be single, duplex, quadruples, or any combination of these.

eight

In the figure above, the lead marked A is the transistor _____.

emitter

Power to low-voltage equipment must be supplied from a(n) _____.

individual portable isolation transformer

Where an equipment grounding conductor is installed underground within an agricultural building, it shall be _____.

insulated

Systems installed to protect loads such as communications, ventilation, or lighting systems that, when stopped, could create hazards or hamper rescue or fire-fighting operations are known as _____.

legally required standby systems

The "Critical Care (Category 1) Space" of patient care spaces in health care facilities are spaces in which failure of equipment or a system is likely to cause _____ injury or death to patients, staff, or visitors.

major

In a health care facility, a television is an example of a(n) _____.

nonessential load

Each patient bed location in a healthcare facility must be supplied by _____.

one or more circuits from the normal electrical system and one or more from the emergency system

Battery capacity can be determined by _____.

performing a load test

An atom that loses a negatively-charged electron becomes a(n) _____.

positive ion

Isolated power systems are used to prevent _____.

power interruption

The devices or disconnects for attended self-service motor fuel dispensing facilities shall be ____ to the attendant.

readily accessible

Temporary wiring shall be ____ immediately upon the completion of construction or purpose for which the wiring was installed.

removed

Health care facilities are often supplied by two or more distribution points; this is known as a(n) _____.

spot network

A single-conversion UPS system _____.

supplies AC power directly to critical loads through a series transformer

Sizing of a generator set for a particular application is _____.

typically done using computer software or manufacturer's literature

Multiwire branch circuits for temporary wiring shall be provided with a means to disconnect simultaneously all ____ conductors where the branch circuit originates.

ungrounded

When possible, transistor casings will have some marking to indicate _____.

which leads are connected to the emitter, collector, or base

All 15A and 20A, 125V, single-phase receptacles installed _____ of agricultural buildings shall be GFCI protected.

Any of these: in areas having and equipotential plane outdoors in dirt confinement areas for livestock

In order to permit the emergence of the maximum number of photons in an LED, the conducting surface _____.

connected to the P-type material is much smaller

Boxes and fittings shall be ____ where installed in a Class III location.

dusttight

Patient bed locations in non-critical spaces must have a minimum of _____.

eight receptacles

In an AC generator, the field windings are energized by the _____.

exciter

A hospital is a building or portion thereof used for the medical, psychiatric, obstetrical, or surgical care, on a 24-hour basis, of ____ or more inpatients.

four

Luminaires installed in Class I, Division 2 locations shall be protected from physical damage by a suitable ____.

guard or by location

The difference between an SCR and a diode is that an SCR _____.

has three terminals

In most cases, feeder conductor size is adjusted when _____.

there are more than three current-carrying conductors in the raceway