Über die Autorin bzw. den Autor

Paul Rosenberg is a leading voice in the industry. He has held nearly every position in the electrical construction industry and was a longtime master electrician. He is a frequent speaker at electrical trade shows and an instructor at various higher education institutions. He is also the author of several Audel books, including the forthcoming Audel Guide to the 2011 National Electrical Code.

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Your study guide for success

To pass your state and local licensing exams, you need knowledge and confi-dence. This comprehensive review guide gives you plenty of both. It's packed with sample questions to help you focus your efforts, review material on all aspects of the 2011 National Electrical Code (NEC)®, the lowdown on business competency requirements, and tips for studying and test-taking that will help you conquer anxiety.

• Learn the definitions, specifi-cations, and regulations of the 2011 NEC

• Acquire test-taking skills with examples of questions and answers that are similar to the ones on the license tests

• Brush up on taxes, unemploy-ment, workers compensation, OSHA, lien laws, and other aspects of the business competency exam

• Get up to speed on telecommunications issues

• Review electrical laws, components, circuits, motors, controllers, generators, electrical power distribution, welding, transformers, safety, and more

• Boost your confidence with studying and test-taking tips

www.audelbooks.com

Aus dem Klappentext

Your study guide for success

To pass your state and local licensing exams, you need knowledge and confi-dence. This comprehensive review guide gives you plenty of both. It's packed with sample questions to help you focus your efforts, review material on all aspects of the 2011 National Electrical Code (NEC)®, the lowdown on business competency requirements, and tips for studying and test-taking that will help you conquer anxiety.

• Learn the definitions, specifi-cations, and regulations of the 2011 NEC

• Acquire test-taking skills with examples of questions and answers that are similar to the ones on the license tests

• Brush up on taxes, unemploy-ment, workers compensation, OSHA, lien laws, and other aspects of the business competency exam

• Get up to speed on telecommunications issues

• Review electrical laws, components, circuits, motors, controllers, generators, electrical power distribution, welding, transformers, safety, and more

• Boost your confidence with studying and test-taking tips

www.audelbooks.com

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Audel Questions and Answers for Electrician's Examinations

John Wiley & Sons

Chapter One

Definitions are covered in Article 100 of the National Electrical Code (NEC). The questions that follow will not cover all of the definitions but only the more pertinent ones. The answers given here are the author's. Refer to Article 100 of the NEC for the official definitions. Some definitions appear in the Code elsewhere than Article 100 (see NEC, Index).

1-1 What does "accessible" mean as applied to wiring methods?

It means readily available to inspection, repair, removal, and so on, without disturbing the building structure or finish;not permanently closed by the structure or finish of a building.

1-2 What does "accessible" mean as applied to equipment?

It means equipment that may be readily reached without climbing over obstacles—that is, not in locked or other hard-to-get-at areas such as panelboards mounted inside kitchen cabinets or mounted in or on the walls above washers and dryers or in closets or bathrooms; service-entrance equipment that can be reached only by going into a closet, behind a stairway, or around some other obstacle. All of these would not be termed "accessible."

1-3 What does "ampacity" mean?

It means the amount of flowing current (in amperes) that a conductor can carry continuously for specific-use conditions and not exceed the temperature rating of the conductor (see NEC, Section 310.10).

1-4 What is a building?

A building may be a structure that stands by itself or one that is separated from another by a fire wall.

1-5 What does "dead front" mean?

It means that no live (energized) parts are exposed to a person operating that electrical equipment.

1-6 What does "approved" mean?

It means any appliance, wiring material, or other electrical equipment that is acceptable to the enforcing authorities. Underwriters Laboratories (UL) is (by far) the most acceptable authority to inspectors. A note of caution: Do not be fooled by a UL label on the motor or cord of an appliance but without such a label on the entire article (see NEC, Section 110.2). The entire appliance must be approved, not just the cord.

1-7 What does "identified" mean as it is applied to equipment?

It means that the equipment is suitable for the particular use or environment, and that it has been evaluated by a qualified electrical testing organization and features a product listing or label indicating its suitability.

1-8 What is a branch circuit?

A branch circuit is the portion of a wiring system that extends beyond the last overcurrent-protective device. In interpreting this, you must not consider the thermal cutout or the motor overload protection as the beginning of the branch circuit. The branch circuit actually begins at the final fusing or circuit-breaker point where the circuit breaks off to supply the motor.

1-9 What is a small-appliance branch circuit?

This is the circuit supplying one or more outlets connecting appliances only; there is no permanently connected lighting on this circuit, except the lighting that may be built into the appliance. This term is most often used in connection with Sections 210.11(C)(1) and 210.52(B) of the NEC, which refers to outlets for small-appliance loads in kitchens, laundries, pantries, and dining and breakfast rooms of dwellings.

1-10 What is a general-purpose circuit?

This is a branch circuit to which lighting and/or appliances may be connected. Lighting may be connected to this circuit, whereas lighting cannot be connected to the circuit mentioned in question 1-10.

1-11 What is a multiwire branch circuit?

A multiwire branch circuit has two or more ungrounded conductors with a potential difference between them and also has a grounded (neutral) conductor with an equal potential difference between it and each of the other wires, for example, a three-wire 120/240-volt system or a 120/208-volt wye system, using two- or three-phase conductors and a grounded conductor. However, in either case, the "hot" wires must not be tied to one phase but must be connected to different phases to make the system a multiwire circuit (see NEC, Section 210.4).

1-12 What is a circuit breaker?

It is a device that is designed not only to open and close a circuit nonautomatically but also to open the circuit automatically at a predetermined current-overload value. The circuit breaker may be thermally or magnetically operated; however, ambient temperatures affect the operation of the thermally operated type, so that the trip value of the current is not as stable as with the magnetic type.

1-13 What is a current-carrying conductor?

It is a conductor that is expected to carry current under normal operating conditions.

1-14 What is a non-current-carrying conductor?

It is one that carries current only in the event of a malfunction of equipment or wiring. An equipment grounding conductor is a good example; it is employed for protection and is quite a necessary part of the wiring system, but it is not used for carrying current, except in the case of faulty operation, where it aids in tripping the overcurrent-protective device.

1-15 What is a pressure connector (solderless)?

It is a device that establishes a good electrical connection between two or more conductors by some means of mechanical pressure. A pressure connector is used in place of soldering connections and is required to be of an approved type. A wirenut is the most common connector of this type.

1-16 What is meant by "demand factor"?

This is the ratio between the maximum demand on a system or part of a system and the total connected load on the same system or part of the system.

1-17 What is meant by "dusttight"?

It means the capacity to keep dust out of the enclosing case so that dust cannot interfere with normal operation. This is discussed further in connection with Articles 500 and 502 of the NEC, both of which cover hazardous (classified) locations.

1-18 What is meant by "explosionproof apparatus"?

It means an apparatus enclosed in a case that is capable of sustaining an explosion that may occur within itself and is also capable of preventing ignition of specified gases or vapors surrounding the enclosure by sparks, flashes, or explosion of the gases or vapors within; it must also operate at a temperature that will not ignite any flammable atmosphere or residue surrounding it. If an explosion does occur within the equipment, the gases are allowed to escape either by a ground joint or by threads, and the escaping gases are thereby cooled to a temperature low enough to inhibit the ignition of any external gases.

1-19 What are feeders?

Feeders are the circuit conductors between the service equipment or the source of a separately derived system and the final branch-circuit overcurrent device or devices. Generally, feeders are comparatively large in size and supply a feeder panel, which is...